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-rw-r--r--drivers/Kconfig2
-rw-r--r--drivers/Makefile1
-rw-r--r--drivers/block/Kconfig6
-rw-r--r--drivers/block/Makefile2
-rw-r--r--drivers/block/lguest_blk.c421
-rw-r--r--drivers/block/virtio_blk.c308
-rw-r--r--drivers/char/Kconfig4
-rw-r--r--drivers/char/Makefile2
-rw-r--r--drivers/char/hvc_lguest.c177
-rw-r--r--drivers/char/virtio_console.c225
-rw-r--r--drivers/kvm/Kconfig4
-rw-r--r--drivers/lguest/Kconfig13
-rw-r--r--drivers/lguest/Makefile10
-rw-r--r--drivers/lguest/core.c568
-rw-r--r--drivers/lguest/hypercalls.c177
-rw-r--r--drivers/lguest/interrupts_and_traps.c125
-rw-r--r--drivers/lguest/io.c626
-rw-r--r--drivers/lguest/lg.h189
-rw-r--r--drivers/lguest/lguest.c1108
-rw-r--r--drivers/lguest/lguest_asm.S93
-rw-r--r--drivers/lguest/lguest_bus.c218
-rw-r--r--drivers/lguest/lguest_device.c373
-rw-r--r--drivers/lguest/lguest_user.c138
-rw-r--r--drivers/lguest/page_tables.c250
-rw-r--r--drivers/lguest/segments.c28
-rw-r--r--drivers/lguest/x86/core.c577
-rw-r--r--drivers/lguest/x86/switcher_32.S (renamed from drivers/lguest/switcher.S)7
-rw-r--r--drivers/net/Kconfig6
-rw-r--r--drivers/net/Makefile2
-rw-r--r--drivers/net/lguest_net.c555
-rw-r--r--drivers/net/virtio_net.c435
-rw-r--r--drivers/virtio/Kconfig8
-rw-r--r--drivers/virtio/Makefile2
-rw-r--r--drivers/virtio/config.c13
-rw-r--r--drivers/virtio/virtio.c189
-rw-r--r--drivers/virtio/virtio_ring.c313
36 files changed, 2911 insertions, 4264 deletions
diff --git a/drivers/Kconfig b/drivers/Kconfig
index 34f40ea0ba6..f4076d9e990 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -94,5 +94,5 @@ source "drivers/kvm/Kconfig"
source "drivers/uio/Kconfig"
-source "drivers/lguest/Kconfig"
+source "drivers/virtio/Kconfig"
endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index cfe38ffff28..560496b4330 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -91,3 +91,4 @@ obj-$(CONFIG_HID) += hid/
obj-$(CONFIG_PPC_PS3) += ps3/
obj-$(CONFIG_OF) += of/
obj-$(CONFIG_SSB) += ssb/
+obj-$(CONFIG_VIRTIO) += virtio/
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index ce4b1e484e6..4d0119ea9e3 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -425,4 +425,10 @@ config XEN_BLKDEV_FRONTEND
block device driver. It communicates with a back-end driver
in another domain which drives the actual block device.
+config VIRTIO_BLK
+ tristate "Virtio block driver (EXPERIMENTAL)"
+ depends on EXPERIMENTAL && VIRTIO
+ ---help---
+ This is the virtual block driver for lguest. Say Y or M.
+
endif # BLK_DEV
diff --git a/drivers/block/Makefile b/drivers/block/Makefile
index 014e72121b5..7691505a2e1 100644
--- a/drivers/block/Makefile
+++ b/drivers/block/Makefile
@@ -25,10 +25,10 @@ obj-$(CONFIG_SUNVDC) += sunvdc.o
obj-$(CONFIG_BLK_DEV_UMEM) += umem.o
obj-$(CONFIG_BLK_DEV_NBD) += nbd.o
obj-$(CONFIG_BLK_DEV_CRYPTOLOOP) += cryptoloop.o
+obj-$(CONFIG_VIRTIO_BLK) += virtio_blk.o
obj-$(CONFIG_VIODASD) += viodasd.o
obj-$(CONFIG_BLK_DEV_SX8) += sx8.o
obj-$(CONFIG_BLK_DEV_UB) += ub.o
obj-$(CONFIG_XEN_BLKDEV_FRONTEND) += xen-blkfront.o
-obj-$(CONFIG_LGUEST_BLOCK) += lguest_blk.o
diff --git a/drivers/block/lguest_blk.c b/drivers/block/lguest_blk.c
deleted file mode 100644
index fa8e42341b8..00000000000
--- a/drivers/block/lguest_blk.c
+++ /dev/null
@@ -1,421 +0,0 @@
-/*D:400
- * The Guest block driver
- *
- * This is a simple block driver, which appears as /dev/lgba, lgbb, lgbc etc.
- * The mechanism is simple: we place the information about the request in the
- * device page, then use SEND_DMA (containing the data for a write, or an empty
- * "ping" DMA for a read).
- :*/
-/* Copyright 2006 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-//#define DEBUG
-#include <linux/init.h>
-#include <linux/types.h>
-#include <linux/blkdev.h>
-#include <linux/interrupt.h>
-#include <linux/lguest_bus.h>
-
-static char next_block_index = 'a';
-
-/*D:420 Here is the structure which holds all the information we need about
- * each Guest block device.
- *
- * I'm sure at this stage, you're wondering "hey, where was the adventure I was
- * promised?" and thinking "Rusty sucks, I shall say nasty things about him on
- * my blog". I think Real adventures have boring bits, too, and you're in the
- * middle of one. But it gets better. Just not quite yet. */
-struct blockdev
-{
- /* The block queue infrastructure wants a spinlock: it is held while it
- * calls our block request function. We grab it in our interrupt
- * handler so the responses don't mess with new requests. */
- spinlock_t lock;
-
- /* The disk structure registered with kernel. */
- struct gendisk *disk;
-
- /* The major device number for this disk, and the interrupt. We only
- * really keep them here for completeness; we'd need them if we
- * supported device unplugging. */
- int major;
- int irq;
-
- /* The physical address of this device's memory page */
- unsigned long phys_addr;
- /* The mapped memory page for convenient acces. */
- struct lguest_block_page *lb_page;
-
- /* We only have a single request outstanding at a time: this is it. */
- struct lguest_dma dma;
- struct request *req;
-};
-
-/*D:495 We originally used end_request() throughout the driver, but it turns
- * out that end_request() is deprecated, and doesn't actually end the request
- * (which seems like a good reason to deprecate it!). It simply ends the first
- * bio. So if we had 3 bios in a "struct request" we would do all 3,
- * end_request(), do 2, end_request(), do 1 and end_request(): twice as much
- * work as we needed to do.
- *
- * This reinforced to me that I do not understand the block layer.
- *
- * Nonetheless, Jens Axboe gave me this nice helper to end all chunks of a
- * request. This improved disk speed by 130%. */
-static void end_entire_request(struct request *req, int uptodate)
-{
- if (end_that_request_first(req, uptodate, req->hard_nr_sectors))
- BUG();
- add_disk_randomness(req->rq_disk);
- blkdev_dequeue_request(req);
- end_that_request_last(req, uptodate);
-}
-
-/* I'm told there are only two stories in the world worth telling: love and
- * hate. So there used to be a love scene here like this:
- *
- * Launcher: We could make beautiful I/O together, you and I.
- * Guest: My, that's a big disk!
- *
- * Unfortunately, it was just too raunchy for our otherwise-gentle tale. */
-
-/*D:490 This is the interrupt handler, called when a block read or write has
- * been completed for us. */
-static irqreturn_t lgb_irq(int irq, void *_bd)
-{
- /* We handed our "struct blockdev" as the argument to request_irq(), so
- * it is passed through to us here. This tells us which device we're
- * dealing with in case we have more than one. */
- struct blockdev *bd = _bd;
- unsigned long flags;
-
- /* We weren't doing anything? Strange, but could happen if we shared
- * interrupts (we don't!). */
- if (!bd->req) {
- pr_debug("No work!\n");
- return IRQ_NONE;
- }
-
- /* Not done yet? That's equally strange. */
- if (!bd->lb_page->result) {
- pr_debug("No result!\n");
- return IRQ_NONE;
- }
-
- /* We have to grab the lock before ending the request. */
- spin_lock_irqsave(&bd->lock, flags);
- /* "result" is 1 for success, 2 for failure: end_entire_request() wants
- * to know whether this succeeded or not. */
- end_entire_request(bd->req, bd->lb_page->result == 1);
- /* Clear out request, it's done. */
- bd->req = NULL;
- /* Reset incoming DMA for next time. */
- bd->dma.used_len = 0;
- /* Ready for more reads or writes */
- blk_start_queue(bd->disk->queue);
- spin_unlock_irqrestore(&bd->lock, flags);
-
- /* The interrupt was for us, we dealt with it. */
- return IRQ_HANDLED;
-}
-
-/*D:480 The block layer's "struct request" contains a number of "struct bio"s,
- * each of which contains "struct bio_vec"s, each of which contains a page, an
- * offset and a length.
- *
- * Fortunately there are iterators to help us walk through the "struct
- * request". Even more fortunately, there were plenty of places to steal the
- * code from. We pack the "struct request" into our "struct lguest_dma" and
- * return the total length. */
-static unsigned int req_to_dma(struct request *req, struct lguest_dma *dma)
-{
- unsigned int i = 0, len = 0;
- struct req_iterator iter;
- struct bio_vec *bvec;
-
- rq_for_each_segment(bvec, req, iter) {
- /* We told the block layer not to give us too many. */
- BUG_ON(i == LGUEST_MAX_DMA_SECTIONS);
- /* If we had a zero-length segment, it would look like
- * the end of the data referred to by the "struct
- * lguest_dma", so make sure that doesn't happen. */
- BUG_ON(!bvec->bv_len);
- /* Convert page & offset to a physical address */
- dma->addr[i] = page_to_phys(bvec->bv_page)
- + bvec->bv_offset;
- dma->len[i] = bvec->bv_len;
- len += bvec->bv_len;
- i++;
- }
- /* If the array isn't full, we mark the end with a 0 length */
- if (i < LGUEST_MAX_DMA_SECTIONS)
- dma->len[i] = 0;
- return len;
-}
-
-/* This creates an empty DMA, useful for prodding the Host without sending data
- * (ie. when we want to do a read) */
-static void empty_dma(struct lguest_dma *dma)
-{
- dma->len[0] = 0;
-}
-
-/*D:470 Setting up a request is fairly easy: */
-static void setup_req(struct blockdev *bd,
- int type, struct request *req, struct lguest_dma *dma)
-{
- /* The type is 1 (write) or 0 (read). */
- bd->lb_page->type = type;
- /* The sector on disk where the read or write starts. */
- bd->lb_page->sector = req->sector;
- /* The result is initialized to 0 (unfinished). */
- bd->lb_page->result = 0;
- /* The current request (so we can end it in the interrupt handler). */
- bd->req = req;
- /* The number of bytes: returned as a side-effect of req_to_dma(),
- * which packs the block layer's "struct request" into our "struct
- * lguest_dma" */
- bd->lb_page->bytes = req_to_dma(req, dma);
-}
-
-/*D:450 Write is pretty straightforward: we pack the request into a "struct
- * lguest_dma", then use SEND_DMA to send the request. */
-static void do_write(struct blockdev *bd, struct request *req)
-{
- struct lguest_dma send;
-
- pr_debug("lgb: WRITE sector %li\n", (long)req->sector);
- setup_req(bd, 1, req, &send);
-
- lguest_send_dma(bd->phys_addr, &send);
-}
-
-/* Read is similar to write, except we pack the request into our receive
- * "struct lguest_dma" and send through an empty DMA just to tell the Host that
- * there's a request pending. */
-static void do_read(struct blockdev *bd, struct request *req)
-{
- struct lguest_dma ping;
-
- pr_debug("lgb: READ sector %li\n", (long)req->sector);
- setup_req(bd, 0, req, &bd->dma);
-
- empty_dma(&ping);
- lguest_send_dma(bd->phys_addr, &ping);
-}
-
-/*D:440 This where requests come in: we get handed the request queue and are
- * expected to pull a "struct request" off it until we've finished them or
- * we're waiting for a reply: */
-static void do_lgb_request(struct request_queue *q)
-{
- struct blockdev *bd;
- struct request *req;
-
-again:
- /* This sometimes returns NULL even on the very first time around. I
- * wonder if it's something to do with letting elves handle the request
- * queue... */
- req = elv_next_request(q);
- if (!req)
- return;
-
- /* We attached the struct blockdev to the disk: get it back */
- bd = req->rq_disk->private_data;
- /* Sometimes we get repeated requests after blk_stop_queue(), but we
- * can only handle one at a time. */
- if (bd->req)
- return;
-
- /* We only do reads and writes: no tricky business! */
- if (!blk_fs_request(req)) {
- pr_debug("Got non-command 0x%08x\n", req->cmd_type);
- req->errors++;
- end_entire_request(req, 0);
- goto again;
- }
-
- if (rq_data_dir(req) == WRITE)
- do_write(bd, req);
- else
- do_read(bd, req);
-
- /* We've put out the request, so stop any more coming in until we get
- * an interrupt, which takes us to lgb_irq() to re-enable the queue. */
- blk_stop_queue(q);
-}
-
-/*D:430 This is the "struct block_device_operations" we attach to the disk at
- * the end of lguestblk_probe(). It doesn't seem to want much. */
-static struct block_device_operations lguestblk_fops = {
- .owner = THIS_MODULE,
-};
-
-/*D:425 Setting up a disk device seems to involve a lot of code. I'm not sure
- * quite why. I do know that the IDE code sent two or three of the maintainers
- * insane, perhaps this is the fringe of the same disease?
- *
- * As in the console code, the probe function gets handed the generic
- * lguest_device from lguest_bus.c: */
-static int lguestblk_probe(struct lguest_device *lgdev)
-{
- struct blockdev *bd;
- int err;
- int irqflags = IRQF_SHARED;
-
- /* First we allocate our own "struct blockdev" and initialize the easy
- * fields. */
- bd = kmalloc(sizeof(*bd), GFP_KERNEL);
- if (!bd)
- return -ENOMEM;
-
- spin_lock_init(&bd->lock);
- bd->irq = lgdev_irq(lgdev);
- bd->req = NULL;
- bd->dma.used_len = 0;
- bd->dma.len[0] = 0;
- /* The descriptor in the lguest_devices array provided by the Host
- * gives the Guest the physical page number of the device's page. */
- bd->phys_addr = (lguest_devices[lgdev->index].pfn << PAGE_SHIFT);
-
- /* We use lguest_map() to get a pointer to the device page */
- bd->lb_page = lguest_map(bd->phys_addr, 1);
- if (!bd->lb_page) {
- err = -ENOMEM;
- goto out_free_bd;
- }
-
- /* We need a major device number: 0 means "assign one dynamically". */
- bd->major = register_blkdev(0, "lguestblk");
- if (bd->major < 0) {
- err = bd->major;
- goto out_unmap;
- }
-
- /* This allocates a "struct gendisk" where we pack all the information
- * about the disk which the rest of Linux sees. The argument is the
- * number of minor devices desired: we need one minor for the main
- * disk, and one for each partition. Of course, we can't possibly know
- * how many partitions are on the disk (add_disk does that).
- */
- bd->disk = alloc_disk(16);
- if (!bd->disk) {
- err = -ENOMEM;
- goto out_unregister_blkdev;
- }
-
- /* Every disk needs a queue for requests to come in: we set up the
- * queue with a callback function (the core of our driver) and the lock
- * to use. */
- bd->disk->queue = blk_init_queue(do_lgb_request, &bd->lock);
- if (!bd->disk->queue) {
- err = -ENOMEM;
- goto out_put_disk;
- }
-
- /* We can only handle a certain number of pointers in our SEND_DMA
- * call, so we set that with blk_queue_max_hw_segments(). This is not
- * to be confused with blk_queue_max_phys_segments() of course! I
- * know, who could possibly confuse the two?
- *
- * Well, it's simple to tell them apart: this one seems to work and the
- * other one didn't. */
- blk_queue_max_hw_segments(bd->disk->queue, LGUEST_MAX_DMA_SECTIONS);
-
- /* Due to technical limitations of our Host (and simple coding) we
- * can't have a single buffer which crosses a page boundary. Tell it
- * here. This means that our maximum request size is 16
- * (LGUEST_MAX_DMA_SECTIONS) pages. */
- blk_queue_segment_boundary(bd->disk->queue, PAGE_SIZE-1);
-
- /* We name our disk: this becomes the device name when udev does its
- * magic thing and creates the device node, such as /dev/lgba.
- * next_block_index is a global which starts at 'a'. Unfortunately
- * this simple increment logic means that the 27th disk will be called
- * "/dev/lgb{". In that case, I recommend having at least 29 disks, so
- * your /dev directory will be balanced. */
- sprintf(bd->disk->disk_name, "lgb%c", next_block_index++);
-
- /* We look to the device descriptor again to see if this device's
- * interrupts are expected to be random. If they are, we tell the irq
- * subsystem. At the moment this bit is always set. */
- if (lguest_devices[lgdev->index].features & LGUEST_DEVICE_F_RANDOMNESS)
- irqflags |= IRQF_SAMPLE_RANDOM;
-
- /* Now we have the name and irqflags, we can request the interrupt; we
- * give it the "struct blockdev" we have set up to pass to lgb_irq()
- * when there is an interrupt. */
- err = request_irq(bd->irq, lgb_irq, irqflags, bd->disk->disk_name, bd);
- if (err)
- goto out_cleanup_queue;
-
- /* We bind our one-entry DMA pool to the key for this block device so
- * the Host can reply to our requests. The key is equal to the
- * physical address of the device's page, which is conveniently
- * unique. */
- err = lguest_bind_dma(bd->phys_addr, &bd->dma, 1, bd->irq);
- if (err)
- goto out_free_irq;
-
- /* We finish our disk initialization and add the disk to the system. */
- bd->disk->major = bd->major;
- bd->disk->first_minor = 0;
- bd->disk->private_data = bd;
- bd->disk->fops = &lguestblk_fops;
- /* This is initialized to the disk size by the Launcher. */
- set_capacity(bd->disk, bd->lb_page->num_sectors);
- add_disk(bd->disk);
-
- printk(KERN_INFO "%s: device %i at major %d\n",
- bd->disk->disk_name, lgdev->index, bd->major);
-
- /* We don't need to keep the "struct blockdev" around, but if we ever
- * implemented device removal, we'd need this. */
- lgdev->private = bd;
- return 0;
-
-out_free_irq:
- free_irq(bd->irq, bd);
-out_cleanup_queue:
- blk_cleanup_queue(bd->disk->queue);
-out_put_disk:
- put_disk(bd->disk);
-out_unregister_blkdev:
- unregister_blkdev(bd->major, "lguestblk");
-out_unmap:
- lguest_unmap(bd->lb_page);
-out_free_bd:
- kfree(bd);
- return err;
-}
-
-/*D:410 The boilerplate code for registering the lguest block driver is just
- * like the console: */
-static struct lguest_driver lguestblk_drv = {
- .name = "lguestblk",
- .owner = THIS_MODULE,
- .device_type = LGUEST_DEVICE_T_BLOCK,
- .probe = lguestblk_probe,
-};
-
-static __init int lguestblk_init(void)
-{
- return register_lguest_driver(&lguestblk_drv);
-}
-module_init(lguestblk_init);
-
-MODULE_DESCRIPTION("Lguest block driver");
-MODULE_LICENSE("GPL");
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
new file mode 100644
index 00000000000..a901eee64ba
--- /dev/null
+++ b/drivers/block/virtio_blk.c
@@ -0,0 +1,308 @@
+//#define DEBUG
+#include <linux/spinlock.h>
+#include <linux/blkdev.h>
+#include <linux/hdreg.h>
+#include <linux/virtio.h>
+#include <linux/virtio_blk.h>
+#include <linux/virtio_blk.h>
+
+static unsigned char virtblk_index = 'a';
+struct virtio_blk
+{
+ spinlock_t lock;
+
+ struct virtio_device *vdev;
+ struct virtqueue *vq;
+
+ /* The disk structure for the kernel. */
+ struct gendisk *disk;
+
+ /* Request tracking. */
+ struct list_head reqs;
+
+ mempool_t *pool;
+
+ /* Scatterlist: can be too big for stack. */
+ struct scatterlist sg[3+MAX_PHYS_SEGMENTS];
+};
+
+struct virtblk_req
+{
+ struct list_head list;
+ struct request *req;
+ struct virtio_blk_outhdr out_hdr;
+ struct virtio_blk_inhdr in_hdr;
+};
+
+static bool blk_done(struct virtqueue *vq)
+{
+ struct virtio_blk *vblk = vq->vdev->priv;
+ struct virtblk_req *vbr;
+ unsigned int len;
+ unsigned long flags;
+
+ spin_lock_irqsave(&vblk->lock, flags);
+ while ((vbr = vblk->vq->vq_ops->get_buf(vblk->vq, &len)) != NULL) {
+ int uptodate;
+ switch (vbr->in_hdr.status) {
+ case VIRTIO_BLK_S_OK:
+ uptodate = 1;
+ break;
+ case VIRTIO_BLK_S_UNSUPP:
+ uptodate = -ENOTTY;
+ break;
+ default:
+ uptodate = 0;
+ break;
+ }
+
+ end_dequeued_request(vbr->req, uptodate);
+ list_del(&vbr->list);
+ mempool_free(vbr, vblk->pool);
+ }
+ /* In case queue is stopped waiting for more buffers. */
+ blk_start_queue(vblk->disk->queue);
+ spin_unlock_irqrestore(&vblk->lock, flags);
+ return true;
+}
+
+static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
+ struct request *req)
+{
+ unsigned long num, out, in;
+ struct virtblk_req *vbr;
+
+ vbr = mempool_alloc(vblk->pool, GFP_ATOMIC);
+ if (!vbr)
+ /* When another request finishes we'll try again. */
+ return false;
+
+ vbr->req = req;
+ if (blk_fs_request(vbr->req)) {
+ vbr->out_hdr.type = 0;
+ vbr->out_hdr.sector = vbr->req->sector;
+ vbr->out_hdr.ioprio = vbr->req->ioprio;
+ } else if (blk_pc_request(vbr->req)) {
+ vbr->out_hdr.type = VIRTIO_BLK_T_SCSI_CMD;
+ vbr->out_hdr.sector = 0;
+ vbr->out_hdr.ioprio = vbr->req->ioprio;
+ } else {
+ /* We don't put anything else in the queue. */
+ BUG();
+ }
+
+ if (blk_barrier_rq(vbr->req))
+ vbr->out_hdr.type |= VIRTIO_BLK_T_BARRIER;
+
+ /* We have to zero this, otherwise blk_rq_map_sg gets upset. */
+ memset(vblk->sg, 0, sizeof(vblk->sg));
+ sg_set_buf(&vblk->sg[0], &vbr->out_hdr, sizeof(vbr->out_hdr));
+ num = blk_rq_map_sg(q, vbr->req, vblk->sg+1);
+ sg_set_buf(&vblk->sg[num+1], &vbr->in_hdr, sizeof(vbr->in_hdr));
+
+ if (rq_data_dir(vbr->req) == WRITE) {
+ vbr->out_hdr.type |= VIRTIO_BLK_T_OUT;
+ out = 1 + num;
+ in = 1;
+ } else {
+ vbr->out_hdr.type |= VIRTIO_BLK_T_IN;
+ out = 1;
+ in = 1 + num;
+ }
+
+ if (vblk->vq->vq_ops->add_buf(vblk->vq, vblk->sg, out, in, vbr)) {
+ mempool_free(vbr, vblk->pool);
+ return false;
+ }
+
+ list_add_tail(&vbr->list, &vblk->reqs);
+ return true;
+}
+
+static void do_virtblk_request(struct request_queue *q)
+{
+ struct virtio_blk *vblk = NULL;
+ struct request *req;
+ unsigned int issued = 0;
+
+ while ((req = elv_next_request(q)) != NULL) {
+ vblk = req->rq_disk->private_data;
+ BUG_ON(req->nr_phys_segments > ARRAY_SIZE(vblk->sg));
+
+ /* If this request fails, stop queue and wait for something to
+ finish to restart it. */
+ if (!do_req(q, vblk, req)) {
+ blk_stop_queue(q);
+ break;
+ }
+ blkdev_dequeue_request(req);
+ issued++;
+ }
+
+ if (issued)
+ vblk->vq->vq_ops->kick(vblk->vq);
+}
+
+static int virtblk_ioctl(struct inode *inode, struct file *filp,
+ unsigned cmd, unsigned long data)
+{
+ return scsi_cmd_ioctl(filp, inode->i_bdev->bd_disk->queue,
+ inode->i_bdev->bd_disk, cmd,
+ (void __user *)data);
+}
+
+static struct block_device_operations virtblk_fops = {
+ .ioctl = virtblk_ioctl,
+ .owner = THIS_MODULE,
+};
+
+static int virtblk_probe(struct virtio_device *vdev)
+{
+ struct virtio_blk *vblk;
+ int err, major;
+ void *token;
+ unsigned int len;
+ u64 cap;
+ u32 v;
+
+ vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
+ if (!vblk) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ INIT_LIST_HEAD(&vblk->reqs);
+ spin_lock_init(&vblk->lock);
+ vblk->vdev = vdev;
+
+ /* We expect one virtqueue, for output. */
+ vblk->vq = vdev->config->find_vq(vdev, blk_done);
+ if (IS_ERR(vblk->vq)) {
+ err = PTR_ERR(vblk->vq);
+ goto out_free_vblk;
+ }
+
+ vblk->pool = mempool_create_kmalloc_pool(1,sizeof(struct virtblk_req));
+ if (!vblk->pool) {
+ err = -ENOMEM;
+ goto out_free_vq;
+ }
+
+ major = register_blkdev(0, "virtblk");
+ if (major < 0) {
+ err = major;
+ goto out_mempool;
+ }
+
+ /* FIXME: How many partitions? How long is a piece of string? */
+ vblk->disk = alloc_disk(1 << 4);
+ if (!vblk->disk) {
+ err = -ENOMEM;
+ goto out_unregister_blkdev;
+ }
+
+ vblk->disk->queue = blk_init_queue(do_virtblk_request, &vblk->lock);
+ if (!vblk->disk->queue) {
+ err = -ENOMEM;
+ goto out_put_disk;
+ }
+
+ sprintf(vblk->disk->disk_name, "vd%c", virtblk_index++);
+ vblk->disk->major = major;
+ vblk->disk->first_minor = 0;
+ vblk->disk->private_data = vblk;
+ vblk->disk->fops = &virtblk_fops;
+
+ /* If barriers are supported, tell block layer that queue is ordered */
+ token = vdev->config->find(vdev, VIRTIO_CONFIG_BLK_F, &len);
+ if (virtio_use_bit(vdev, token, len, VIRTIO_BLK_F_BARRIER))
+ blk_queue_ordered(vblk->disk->queue, QUEUE_ORDERED_TAG, NULL);
+
+ err = virtio_config_val(vdev, VIRTIO_CONFIG_BLK_F_CAPACITY, &cap);
+ if (err) {
+ dev_err(&vdev->dev, "Bad/missing capacity in config\n");
+ goto out_put_disk;
+ }
+
+ /* If capacity is too big, truncate with warning. */
+ if ((sector_t)cap != cap) {
+ dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
+ (unsigned long long)cap);
+ cap = (sector_t)-1;
+ }
+ set_capacity(vblk->disk, cap);
+
+ err = virtio_config_val(vdev, VIRTIO_CONFIG_BLK_F_SIZE_MAX, &v);
+ if (!err)
+ blk_queue_max_segment_size(vblk->disk->queue, v);
+ else if (err != -ENOENT) {
+ dev_err(&vdev->dev, "Bad SIZE_MAX in config\n");
+ goto out_put_disk;
+ }
+
+ err = virtio_config_val(vdev, VIRTIO_CONFIG_BLK_F_SEG_MAX, &v);
+ if (!err)
+ blk_queue_max_hw_segments(vblk->disk->queue, v);
+ else if (err != -ENOENT) {
+ dev_err(&vdev->dev, "Bad SEG_MAX in config\n");
+ goto out_put_disk;
+ }
+
+ add_disk(vblk->disk);
+ return 0;
+
+out_put_disk:
+ put_disk(vblk->disk);
+out_unregister_blkdev:
+ unregister_blkdev(major, "virtblk");
+out_mempool:
+ mempool_destroy(vblk->pool);
+out_free_vq:
+ vdev->config->del_vq(vblk->vq);
+out_free_vblk:
+ kfree(vblk);
+out:
+ return err;
+}
+
+static void virtblk_remove(struct virtio_device *vdev)
+{
+ struct virtio_blk *vblk = vdev->priv;
+ int major = vblk->disk->major;
+
+ BUG_ON(!list_empty(&vblk->reqs));
+ blk_cleanup_queue(vblk->disk->queue);
+ put_disk(vblk->disk);
+ unregister_blkdev(major, "virtblk");
+ mempool_destroy(vblk->pool);
+ kfree(vblk);
+}
+
+static struct virtio_device_id id_table[] = {
+ { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
+ { 0 },
+};
+
+static struct virtio_driver virtio_blk = {
+ .driver.name = KBUILD_MODNAME,
+ .driver.owner = THIS_MODULE,
+ .id_table = id_table,
+ .probe = virtblk_probe,
+ .remove = __devexit_p(virtblk_remove),
+};
+
+static int __init init(void)
+{
+ return register_virtio_driver(&virtio_blk);
+}
+
+static void __exit fini(void)
+{
+ unregister_virtio_driver(&virtio_blk);
+}
+module_init(init);
+module_exit(fini);
+
+MODULE_DEVICE_TABLE(virtio, id_table);
+MODULE_DESCRIPTION("Virtio block driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 65491103e0f..bf18d757b87 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -613,6 +613,10 @@ config HVC_XEN
help
Xen virtual console device driver
+config VIRTIO_CONSOLE
+ bool
+ select HVC_DRIVER
+
config HVCS
tristate "IBM Hypervisor Virtual Console Server support"
depends on PPC_PSERIES
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index c78ff26647e..07304d50e0c 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -42,7 +42,6 @@ obj-$(CONFIG_SYNCLINK_GT) += synclink_gt.o
obj-$(CONFIG_N_HDLC) += n_hdlc.o
obj-$(CONFIG_AMIGA_BUILTIN_SERIAL) += amiserial.o
obj-$(CONFIG_SX) += sx.o generic_serial.o
-obj-$(CONFIG_LGUEST_GUEST) += hvc_lguest.o
obj-$(CONFIG_RIO) += rio/ generic_serial.o
obj-$(CONFIG_HVC_CONSOLE) += hvc_vio.o hvsi.o
obj-$(CONFIG_HVC_ISERIES) += hvc_iseries.o
@@ -50,6 +49,7 @@ obj-$(CONFIG_HVC_RTAS) += hvc_rtas.o
obj-$(CONFIG_HVC_BEAT) += hvc_beat.o
obj-$(CONFIG_HVC_DRIVER) += hvc_console.o
obj-$(CONFIG_HVC_XEN) += hvc_xen.o
+obj-$(CONFIG_VIRTIO_CONSOLE) += virtio_console.o
obj-$(CONFIG_RAW_DRIVER) += raw.o
obj-$(CONFIG_SGI_SNSC) += snsc.o snsc_event.o
obj-$(CONFIG_MSPEC) += mspec.o
diff --git a/drivers/char/hvc_lguest.c b/drivers/char/hvc_lguest.c
deleted file mode 100644
index efccb215583..00000000000
--- a/drivers/char/hvc_lguest.c
+++ /dev/null
@@ -1,177 +0,0 @@
-/*D:300
- * The Guest console driver
- *
- * This is a trivial console driver: we use lguest's DMA mechanism to send
- * bytes out, and register a DMA buffer to receive bytes in. It is assumed to
- * be present and available from the very beginning of boot.
- *
- * Writing console drivers is one of the few remaining Dark Arts in Linux.
- * Fortunately for us, the path of virtual consoles has been well-trodden by
- * the PowerPC folks, who wrote "hvc_console.c" to generically support any
- * virtual console. We use that infrastructure which only requires us to write
- * the basic put_chars and get_chars functions and call the right register
- * functions.
- :*/
-
-/*M:002 The console can be flooded: while the Guest is processing input the
- * Host can send more. Buffering in the Host could alleviate this, but it is a
- * difficult problem in general. :*/
-/* Copyright (C) 2006 Rusty Russell, IBM Corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-#include <linux/err.h>
-#include <linux/init.h>
-#include <linux/lguest_bus.h>
-#include <asm/paravirt.h>
-#include "hvc_console.h"
-
-/*D:340 This is our single console input buffer, with associated "struct
- * lguest_dma" referring to it. Note the 0-terminated length array, and the
- * use of physical address for the buffer itself. */
-static char inbuf[256];
-static struct lguest_dma cons_input = { .used_len = 0,
- .addr[0] = __pa(inbuf),
- .len[0] = sizeof(inbuf),
- .len[1] = 0 };
-
-/*D:310 The put_chars() callback is pretty straightforward.
- *
- * First we put the pointer and length in a "struct lguest_dma": we only have
- * one pointer, so we set the second length to 0. Then we use SEND_DMA to send
- * the data to (Host) buffers attached to the console key. Usually a device's
- * key is a physical address within the device's memory, but because the
- * console device doesn't have any associated physical memory, we use the
- * LGUEST_CONSOLE_DMA_KEY constant (aka 0). */
-static int put_chars(u32 vtermno, const char *buf, int count)
-{
- struct lguest_dma dma;
-
- /* FIXME: DMA buffers in a "struct lguest_dma" are not allowed
- * to go over page boundaries. This never seems to happen,
- * but if it did we'd need to fix this code. */
- dma.len[0] = count;
- dma.len[1] = 0;
- dma.addr[0] = __pa(buf);
-
- lguest_send_dma(LGUEST_CONSOLE_DMA_KEY, &dma);
- /* We're expected to return the amount of data we wrote: all of it. */
- return count;
-}
-
-/*D:350 get_chars() is the callback from the hvc_console infrastructure when
- * an interrupt is received.
- *
- * Firstly we see if our buffer has been filled: if not, we return. The rest
- * of the code deals with the fact that the hvc_console() infrastructure only
- * asks us for 16 bytes at a time. We keep a "cons_offset" variable for
- * partially-read buffers. */
-static int get_chars(u32 vtermno, char *buf, int count)
-{
- static int cons_offset;
-
- /* Nothing left to see here... */
- if (!cons_input.used_len)
- return 0;
-
- /* You want more than we have to give? Well, try wanting less! */
- if (cons_input.used_len - cons_offset < count)
- count = cons_input.used_len - cons_offset;
-
- /* Copy across to their buffer and increment offset. */
- memcpy(buf, inbuf + cons_offset, count);
- cons_offset += count;
-
- /* Finished? Zero offset, and reset cons_input so Host will use it
- * again. */
- if (cons_offset == cons_input.used_len) {
- cons_offset = 0;
- cons_input.used_len = 0;
- }
- return count;
-}
-/*:*/
-
-static struct hv_ops lguest_cons = {
- .get_chars = get_chars,
- .put_chars = put_chars,
-};
-
-/*D:320 Console drivers are initialized very early so boot messages can go
- * out. At this stage, the console is output-only. Our driver checks we're a
- * Guest, and if so hands hvc_instantiate() the console number (0), priority
- * (0), and the struct hv_ops containing the put_chars() function. */
-static int __init cons_init(void)
-{
- if (strcmp(pv_info.name, "lguest") != 0)
- return 0;
-
- return hvc_instantiate(0, 0, &lguest_cons);
-}
-console_initcall(cons_init);
-
-/*D:370 To set up and manage our virtual console, we call hvc_alloc() and
- * stash the result in the private pointer of the "struct lguest_device".
- * Since we never remove the console device we never need this pointer again,
- * but using ->private is considered good form, and you never know who's going
- * to copy your driver.
- *
- * Once the console is set up, we bind our input buffer ready for input. */
-static int lguestcons_probe(struct lguest_device *lgdev)
-{
- int err;
-
- /* The first argument of hvc_alloc() is the virtual console number, so
- * we use zero. The second argument is the interrupt number.
- *
- * The third argument is a "struct hv_ops" containing the put_chars()
- * and get_chars() pointers. The final argument is the output buffer
- * size: we use 256 and expect the Host to have room for us to send
- * that much. */
- lgdev->private = hvc_alloc(0, lgdev_irq(lgdev), &lguest_cons, 256);
- if (IS_ERR(lgdev->private))
- return PTR_ERR(lgdev->private);
-
- /* We bind a single DMA buffer at key LGUEST_CONSOLE_DMA_KEY.
- * "cons_input" is that statically-initialized global DMA buffer we saw
- * above, and we also give the interrupt we want. */
- err = lguest_bind_dma(LGUEST_CONSOLE_DMA_KEY, &cons_input, 1,
- lgdev_irq(lgdev));
- if (err)
- printk("lguest console: failed to bind buffer.\n");
- return err;
-}
-/* Note the use of lgdev_irq() for the interrupt number. We tell hvc_alloc()
- * to expect input when this interrupt is triggered, and then tell
- * lguest_bind_dma() that is the interrupt to send us when input comes in. */
-
-/*D:360 From now on the console driver follows standard Guest driver form:
- * register_lguest_driver() registers the device type and probe function, and
- * the probe function sets up the device.
- *
- * The standard "struct lguest_driver": */
-static struct lguest_driver lguestcons_drv = {
- .name = "lguestcons",
- .owner = THIS_MODULE,
- .device_type = LGUEST_DEVICE_T_CONSOLE,
- .probe = lguestcons_probe,
-};
-
-/* The standard init function */
-static int __init hvc_lguest_init(void)
-{
- return register_lguest_driver(&lguestcons_drv);
-}
-module_init(hvc_lguest_init);
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
new file mode 100644
index 00000000000..100e8a201e3
--- /dev/null
+++ b/drivers/char/virtio_console.c
@@ -0,0 +1,225 @@
+/*D:300
+ * The Guest console driver
+ *
+ * Writing console drivers is one of the few remaining Dark Arts in Linux.
+ * Fortunately for us, the path of virtual consoles has been well-trodden by
+ * the PowerPC folks, who wrote "hvc_console.c" to generically support any
+ * virtual console. We use that infrastructure which only requires us to write
+ * the basic put_chars and get_chars functions and call the right register
+ * functions.
+ :*/
+
+/*M:002 The console can be flooded: while the Guest is processing input the
+ * Host can send more. Buffering in the Host could alleviate this, but it is a
+ * difficult problem in general. :*/
+/* Copyright (C) 2006, 2007 Rusty Russell, IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/virtio.h>
+#include <linux/virtio_console.h>
+#include "hvc_console.h"
+
+/*D:340 These represent our input and output console queues, and the virtio
+ * operations for them. */
+static struct virtqueue *in_vq, *out_vq;
+static struct virtio_device *vdev;
+
+/* This is our input buffer, and how much data is left in it. */
+static unsigned int in_len;
+static char *in, *inbuf;
+
+/* The operations for our console. */
+static struct hv_ops virtio_cons;
+
+/*D:310 The put_chars() callback is pretty straightforward.
+ *
+ * We turn the characters into a scatter-gather list, add it to the output
+ * queue and then kick the Host. Then we sit here waiting for it to finish:
+ * inefficient in theory, but in practice implementations will do it
+ * immediately (lguest's Launcher does). */
+static int put_chars(u32 vtermno, const char *buf, int count)
+{
+ struct scatterlist sg[1];
+ unsigned int len;
+
+ /* This is a convenient routine to initialize a single-elem sg list */
+ sg_init_one(sg, buf, count);
+
+ /* add_buf wants a token to identify this buffer: we hand it any
+ * non-NULL pointer, since there's only ever one buffer. */
+ if (out_vq->vq_ops->add_buf(out_vq, sg, 1, 0, (void *)1) == 0) {
+ /* Tell Host to go! */
+ out_vq->vq_ops->kick(out_vq);
+ /* Chill out until it's done with the buffer. */
+ while (!out_vq->vq_ops->get_buf(out_vq, &len))
+ cpu_relax();
+ }
+
+ /* We're expected to return the amount of data we wrote: all of it. */
+ return count;
+}
+
+/* Create a scatter-gather list representing our input buffer and put it in the
+ * queue. */
+static void add_inbuf(void)
+{
+ struct scatterlist sg[1];
+ sg_init_one(sg, inbuf, PAGE_SIZE);
+
+ /* We should always be able to add one buffer to an empty queue. */
+ if (in_vq->vq_ops->add_buf(in_vq, sg, 0, 1, inbuf) != 0)
+ BUG();
+ in_vq->vq_ops->kick(in_vq);
+}
+
+/*D:350 get_chars() is the callback from the hvc_console infrastructure when
+ * an interrupt is received.
+ *
+ * Most of the code deals with the fact that the hvc_console() infrastructure
+ * only asks us for 16 bytes at a time. We keep in_offset and in_used fields
+ * for partially-filled buffers. */
+static int get_chars(u32 vtermno, char *buf, int count)
+{
+ /* If we don't have an input queue yet, we can't get input. */
+ BUG_ON(!in_vq);
+
+ /* No buffer? Try to get one. */
+ if (!in_len) {
+ in = in_vq->vq_ops->get_buf(in_vq, &in_len);
+ if (!in)
+ return 0;
+ }
+
+ /* You want more than we have to give? Well, try wanting less! */
+ if (in_len < count)
+ count = in_len;
+
+ /* Copy across to their buffer and increment offset. */
+ memcpy(buf, in, count);
+ in += count;
+ in_len -= count;
+
+ /* Finished? Re-register buffer so Host will use it again. */
+ if (in_len == 0)
+ add_inbuf();
+
+ return count;
+}
+/*:*/
+
+/*D:320 Console drivers are initialized very early so boot messages can go out,
+ * so we do things slightly differently from the generic virtio initialization
+ * of the net and block drivers.
+ *
+ * At this stage, the console is output-only. It's too early to set up a
+ * virtqueue, so we let the drivers do some boutique early-output thing. */
+int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int))
+{
+ virtio_cons.put_chars = put_chars;
+ return hvc_instantiate(0, 0, &virtio_cons);
+}
+
+/*D:370 Once we're further in boot, we get probed like any other virtio device.
+ * At this stage we set up the output virtqueue.
+ *
+ * To set up and manage our virtual console, we call hvc_alloc(). Since we
+ * never remove the console device we never need this pointer again.
+ *
+ * Finally we put our input buffer in the input queue, ready to receive. */
+static int virtcons_probe(struct virtio_device *dev)
+{
+ int err;
+ struct hvc_struct *hvc;
+
+ vdev = dev;
+
+ /* This is the scratch page we use to receive console input */
+ inbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!inbuf) {
+ err = -ENOMEM;
+ goto fail;
+ }
+
+ /* Find the input queue. */
+ /* FIXME: This is why we want to wean off hvc: we do nothing
+ * when input comes in. */
+ in_vq = vdev->config->find_vq(vdev, NULL);
+ if (IS_ERR(in_vq)) {
+ err = PTR_ERR(in_vq);
+ goto free;
+ }
+
+ out_vq = vdev->config->find_vq(vdev, NULL);
+ if (IS_ERR(out_vq)) {
+ err = PTR_ERR(out_vq);
+ goto free_in_vq;
+ }
+
+ /* Start using the new console output. */
+ virtio_cons.get_chars = get_chars;
+ virtio_cons.put_chars = put_chars;
+
+ /* The first argument of hvc_alloc() is the virtual console number, so
+ * we use zero. The second argument is the interrupt number; we
+ * currently leave this as zero: it would be better not to use the
+ * hvc mechanism and fix this (FIXME!).
+ *
+ * The third argument is a "struct hv_ops" containing the put_chars()
+ * and get_chars() pointers. The final argument is the output buffer
+ * size: we can do any size, so we put PAGE_SIZE here. */
+ hvc = hvc_alloc(0, 0, &virtio_cons, PAGE_SIZE);
+ if (IS_ERR(hvc)) {
+ err = PTR_ERR(hvc);
+ goto free_out_vq;
+ }
+
+ /* Register the input buffer the first time. */
+ add_inbuf();
+ return 0;
+
+free_out_vq:
+ vdev->config->del_vq(out_vq);
+free_in_vq:
+ vdev->config->del_vq(in_vq);
+free:
+ kfree(inbuf);
+fail:
+ return err;
+}
+
+static struct virtio_device_id id_table[] = {
+ { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID },
+ { 0 },
+};
+
+static struct virtio_driver virtio_console = {
+ .driver.name = KBUILD_MODNAME,
+ .driver.owner = THIS_MODULE,
+ .id_table = id_table,
+ .probe = virtcons_probe,
+};
+
+static int __init init(void)
+{
+ return register_virtio_driver(&virtio_console);
+}
+module_init(init);
+
+MODULE_DEVICE_TABLE(virtio, id_table);
+MODULE_DESCRIPTION("Virtio console driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/kvm/Kconfig b/drivers/kvm/Kconfig
index 8749fa4ffce..656920636cb 100644
--- a/drivers/kvm/Kconfig
+++ b/drivers/kvm/Kconfig
@@ -47,4 +47,8 @@ config KVM_AMD
Provides support for KVM on AMD processors equipped with the AMD-V
(SVM) extensions.
+# OK, it's a little counter-intuitive to do this, but it puts it neatly under
+# the virtualization menu.
+source drivers/lguest/Kconfig
+
endif # VIRTUALIZATION
diff --git a/drivers/lguest/Kconfig b/drivers/lguest/Kconfig
index 41e2250613a..7eb9ecff8f4 100644
--- a/drivers/lguest/Kconfig
+++ b/drivers/lguest/Kconfig
@@ -1,7 +1,6 @@
config LGUEST
tristate "Linux hypervisor example code"
- depends on X86 && PARAVIRT && EXPERIMENTAL && !X86_PAE && FUTEX
- select LGUEST_GUEST
+ depends on X86_32 && EXPERIMENTAL && !X86_PAE && FUTEX && !(X86_VISWS || X86_VOYAGER)
select HVC_DRIVER
---help---
This is a very simple module which allows you to run
@@ -18,13 +17,3 @@ config LGUEST_GUEST
The guest needs code built-in, even if the host has lguest
support as a module. The drivers are tiny, so we build them
in too.
-
-config LGUEST_NET
- tristate
- default y
- depends on LGUEST_GUEST && NET
-
-config LGUEST_BLOCK
- tristate
- default y
- depends on LGUEST_GUEST && BLOCK
diff --git a/drivers/lguest/Makefile b/drivers/lguest/Makefile
index e5047471c33..5e8272d296d 100644
--- a/drivers/lguest/Makefile
+++ b/drivers/lguest/Makefile
@@ -1,10 +1,12 @@
-# Guest requires the paravirt_ops replacement and the bus driver.
-obj-$(CONFIG_LGUEST_GUEST) += lguest.o lguest_asm.o lguest_bus.o
+# Guest requires the device configuration and probing code.
+obj-$(CONFIG_LGUEST_GUEST) += lguest_device.o
# Host requires the other files, which can be a module.
obj-$(CONFIG_LGUEST) += lg.o
-lg-y := core.o hypercalls.o page_tables.o interrupts_and_traps.o \
- segments.o io.o lguest_user.o switcher.o
+lg-y = core.o hypercalls.o page_tables.o interrupts_and_traps.o \
+ segments.o lguest_user.o
+
+lg-$(CONFIG_X86_32) += x86/switcher_32.o x86/core.o
Preparation Preparation!: PREFIX=P
Guest: PREFIX=G
diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c
index a0788c12b39..35d19ae58de 100644
--- a/drivers/lguest/core.c
+++ b/drivers/lguest/core.c
@@ -11,58 +11,20 @@
#include <linux/vmalloc.h>
#include <linux/cpu.h>
#include <linux/freezer.h>
+#include <linux/highmem.h>
#include <asm/paravirt.h>
-#include <asm/desc.h>
#include <asm/pgtable.h>
#include <asm/uaccess.h>
#include <asm/poll.h>
-#include <asm/highmem.h>
#include <asm/asm-offsets.h>
-#include <asm/i387.h>
#include "lg.h"
-/* Found in switcher.S */
-extern char start_switcher_text[], end_switcher_text[], switch_to_guest[];
-extern unsigned long default_idt_entries[];
-
-/* Every guest maps the core switcher code. */
-#define SHARED_SWITCHER_PAGES \
- DIV_ROUND_UP(end_switcher_text - start_switcher_text, PAGE_SIZE)
-/* Pages for switcher itself, then two pages per cpu */
-#define TOTAL_SWITCHER_PAGES (SHARED_SWITCHER_PAGES + 2 * NR_CPUS)
-
-/* We map at -4M for ease of mapping into the guest (one PTE page). */
-#define SWITCHER_ADDR 0xFFC00000
static struct vm_struct *switcher_vma;
static struct page **switcher_page;
-static int cpu_had_pge;
-static struct {
- unsigned long offset;
- unsigned short segment;
-} lguest_entry;
-
/* This One Big lock protects all inter-guest data structures. */
DEFINE_MUTEX(lguest_lock);
-static DEFINE_PER_CPU(struct lguest *, last_guest);
-
-/* FIXME: Make dynamic. */
-#define MAX_LGUEST_GUESTS 16
-struct lguest lguests[MAX_LGUEST_GUESTS];
-
-/* Offset from where switcher.S was compiled to where we've copied it */
-static unsigned long switcher_offset(void)
-{
- return SWITCHER_ADDR - (unsigned long)start_switcher_text;
-}
-
-/* This cpu's struct lguest_pages. */
-static struct lguest_pages *lguest_pages(unsigned int cpu)
-{
- return &(((struct lguest_pages *)
- (SWITCHER_ADDR + SHARED_SWITCHER_PAGES*PAGE_SIZE))[cpu]);
-}
/*H:010 We need to set up the Switcher at a high virtual address. Remember the
* Switcher is a few hundred bytes of assembler code which actually changes the
@@ -73,9 +35,7 @@ static struct lguest_pages *lguest_pages(unsigned int cpu)
* Host since it will be running as the switchover occurs.
*
* Trying to map memory at a particular address is an unusual thing to do, so
- * it's not a simple one-liner. We also set up the per-cpu parts of the
- * Switcher here.
- */
+ * it's not a simple one-liner. */
static __init int map_switcher(void)
{
int i, err;
@@ -132,90 +92,11 @@ static __init int map_switcher(void)
goto free_vma;
}
- /* Now the switcher is mapped at the right address, we can't fail!
- * Copy in the compiled-in Switcher code (from switcher.S). */
+ /* Now the Switcher is mapped at the right address, we can't fail!
+ * Copy in the compiled-in Switcher code (from <arch>_switcher.S). */
memcpy(switcher_vma->addr, start_switcher_text,
end_switcher_text - start_switcher_text);
- /* Most of the switcher.S doesn't care that it's been moved; on Intel,
- * jumps are relative, and it doesn't access any references to external
- * code or data.
- *
- * The only exception is the interrupt handlers in switcher.S: their
- * addresses are placed in a table (default_idt_entries), so we need to
- * update the table with the new addresses. switcher_offset() is a
- * convenience function which returns the distance between the builtin
- * switcher code and the high-mapped copy we just made. */
- for (i = 0; i < IDT_ENTRIES; i++)
- default_idt_entries[i] += switcher_offset();
-
- /*
- * Set up the Switcher's per-cpu areas.
- *
- * Each CPU gets two pages of its own within the high-mapped region
- * (aka. "struct lguest_pages"). Much of this can be initialized now,
- * but some depends on what Guest we are running (which is set up in
- * copy_in_guest_info()).
- */
- for_each_possible_cpu(i) {
- /* lguest_pages() returns this CPU's two pages. */
- struct lguest_pages *pages = lguest_pages(i);
- /* This is a convenience pointer to make the code fit one
- * statement to a line. */
- struct lguest_ro_state *state = &pages->state;
-
- /* The Global Descriptor Table: the Host has a different one
- * for each CPU. We keep a descriptor for the GDT which says
- * where it is and how big it is (the size is actually the last
- * byte, not the size, hence the "-1"). */
- state->host_gdt_desc.size = GDT_SIZE-1;
- state->host_gdt_desc.address = (long)get_cpu_gdt_table(i);
-
- /* All CPUs on the Host use the same Interrupt Descriptor
- * Table, so we just use store_idt(), which gets this CPU's IDT
- * descriptor. */
- store_idt(&state->host_idt_desc);
-
- /* The descriptors for the Guest's GDT and IDT can be filled
- * out now, too. We copy the GDT & IDT into ->guest_gdt and
- * ->guest_idt before actually running the Guest. */
- state->guest_idt_desc.size = sizeof(state->guest_idt)-1;
- state->guest_idt_desc.address = (long)&state->guest_idt;
- state->guest_gdt_desc.size = sizeof(state->guest_gdt)-1;
- state->guest_gdt_desc.address = (long)&state->guest_gdt;
-
- /* We know where we want the stack to be when the Guest enters
- * the switcher: in pages->regs. The stack grows upwards, so
- * we start it at the end of that structure. */
- state->guest_tss.esp0 = (long)(&pages->regs + 1);
- /* And this is the GDT entry to use for the stack: we keep a
- * couple of special LGUEST entries. */
- state->guest_tss.ss0 = LGUEST_DS;
-
- /* x86 can have a finegrained bitmap which indicates what I/O
- * ports the process can use. We set it to the end of our
- * structure, meaning "none". */
- state->guest_tss.io_bitmap_base = sizeof(state->guest_tss);
-
- /* Some GDT entries are the same across all Guests, so we can
- * set them up now. */
- setup_default_gdt_entries(state);
- /* Most IDT entries are the same for all Guests, too.*/
- setup_default_idt_entries(state, default_idt_entries);
-
- /* The Host needs to be able to use the LGUEST segments on this
- * CPU, too, so put them in the Host GDT. */
- get_cpu_gdt_table(i)[GDT_ENTRY_LGUEST_CS] = FULL_EXEC_SEGMENT;
- get_cpu_gdt_table(i)[GDT_ENTRY_LGUEST_DS] = FULL_SEGMENT;
- }
-
- /* In the Switcher, we want the %cs segment register to use the
- * LGUEST_CS GDT entry: we've put that in the Host and Guest GDTs, so
- * it will be undisturbed when we switch. To change %cs and jump we
- * need this structure to feed to Intel's "lcall" instruction. */
- lguest_entry.offset = (long)switch_to_guest + switcher_offset();
- lguest_entry.segment = LGUEST_CS;
-
printk(KERN_INFO "lguest: mapped switcher at %p\n",
switcher_vma->addr);
/* And we succeeded... */
@@ -247,86 +128,12 @@ static void unmap_switcher(void)
__free_pages(switcher_page[i], 0);
}
-/*H:130 Our Guest is usually so well behaved; it never tries to do things it
- * isn't allowed to. Unfortunately, Linux's paravirtual infrastructure isn't
- * quite complete, because it doesn't contain replacements for the Intel I/O
- * instructions. As a result, the Guest sometimes fumbles across one during
- * the boot process as it probes for various things which are usually attached
- * to a PC.
- *
- * When the Guest uses one of these instructions, we get trap #13 (General
- * Protection Fault) and come here. We see if it's one of those troublesome
- * instructions and skip over it. We return true if we did. */
-static int emulate_insn(struct lguest *lg)
-{
- u8 insn;
- unsigned int insnlen = 0, in = 0, shift = 0;
- /* The eip contains the *virtual* address of the Guest's instruction:
- * guest_pa just subtracts the Guest's page_offset. */
- unsigned long physaddr = guest_pa(lg, lg->regs->eip);
-
- /* The guest_pa() function only works for Guest kernel addresses, but
- * that's all we're trying to do anyway. */
- if (lg->regs->eip < lg->page_offset)
- return 0;
-
- /* Decoding x86 instructions is icky. */
- lgread(lg, &insn, physaddr, 1);
-
- /* 0x66 is an "operand prefix". It means it's using the upper 16 bits
- of the eax register. */
- if (insn == 0x66) {
- shift = 16;
- /* The instruction is 1 byte so far, read the next byte. */
- insnlen = 1;
- lgread(lg, &insn, physaddr + insnlen, 1);
- }
-
- /* We can ignore the lower bit for the moment and decode the 4 opcodes
- * we need to emulate. */
- switch (insn & 0xFE) {
- case 0xE4: /* in <next byte>,%al */
- insnlen += 2;
- in = 1;
- break;
- case 0xEC: /* in (%dx),%al */
- insnlen += 1;
- in = 1;
- break;
- case 0xE6: /* out %al,<next byte> */
- insnlen += 2;
- break;
- case 0xEE: /* out %al,(%dx) */
- insnlen += 1;
- break;
- default:
- /* OK, we don't know what this is, can't emulate. */
- return 0;
- }
-
- /* If it was an "IN" instruction, they expect the result to be read
- * into %eax, so we change %eax. We always return all-ones, which
- * traditionally means "there's nothing there". */
- if (in) {
- /* Lower bit tells is whether it's a 16 or 32 bit access */
- if (insn & 0x1)
- lg->regs->eax = 0xFFFFFFFF;
- else
- lg->regs->eax |= (0xFFFF << shift);
- }
- /* Finally, we've "done" the instruction, so move past it. */
- lg->regs->eip += insnlen;
- /* Success! */
- return 1;
-}
-/*:*/
-
/*L:305
* Dealing With Guest Memory.
*
* When the Guest gives us (what it thinks is) a physical address, we can use
- * the normal copy_from_user() & copy_to_user() on that address: remember,
- * Guest physical == Launcher virtual.
+ * the normal copy_from_user() & copy_to_user() on the corresponding place in
+ * the memory region allocated by the Launcher.
*
* But we can't trust the Guest: it might be trying to access the Launcher
* code. We have to check that the range is below the pfn_limit the Launcher
@@ -338,148 +145,27 @@ int lguest_address_ok(const struct lguest *lg,
return (addr+len) / PAGE_SIZE < lg->pfn_limit && (addr+len >= addr);
}
-/* This is a convenient routine to get a 32-bit value from the Guest (a very
- * common operation). Here we can see how useful the kill_lguest() routine we
- * met in the Launcher can be: we return a random value (0) instead of needing
- * to return an error. */
-u32 lgread_u32(struct lguest *lg, unsigned long addr)
-{
- u32 val = 0;
-
- /* Don't let them access lguest binary. */
- if (!lguest_address_ok(lg, addr, sizeof(val))
- || get_user(val, (u32 __user *)addr) != 0)
- kill_guest(lg, "bad read address %#lx", addr);
- return val;
-}
-
-/* Same thing for writing a value. */
-void lgwrite_u32(struct lguest *lg, unsigned long addr, u32 val)
-{
- if (!lguest_address_ok(lg, addr, sizeof(val))
- || put_user(val, (u32 __user *)addr) != 0)
- kill_guest(lg, "bad write address %#lx", addr);
-}
-
-/* This routine is more generic, and copies a range of Guest bytes into a
- * buffer. If the copy_from_user() fails, we fill the buffer with zeroes, so
- * the caller doesn't end up using uninitialized kernel memory. */
-void lgread(struct lguest *lg, void *b, unsigned long addr, unsigned bytes)
+/* This routine copies memory from the Guest. Here we can see how useful the
+ * kill_lguest() routine we met in the Launcher can be: we return a random
+ * value (all zeroes) instead of needing to return an error. */
+void __lgread(struct lguest *lg, void *b, unsigned long addr, unsigned bytes)
{
if (!lguest_address_ok(lg, addr, bytes)
- || copy_from_user(b, (void __user *)addr, bytes) != 0) {
+ || copy_from_user(b, lg->mem_base + addr, bytes) != 0) {
/* copy_from_user should do this, but as we rely on it... */
memset(b, 0, bytes);
kill_guest(lg, "bad read address %#lx len %u", addr, bytes);
}
}
-/* Similarly, our generic routine to copy into a range of Guest bytes. */
-void lgwrite(struct lguest *lg, unsigned long addr, const void *b,
- unsigned bytes)
+/* This is the write (copy into guest) version. */
+void __lgwrite(struct lguest *lg, unsigned long addr, const void *b,
+ unsigned bytes)
{
if (!lguest_address_ok(lg, addr, bytes)
- || copy_to_user((void __user *)addr, b, bytes) != 0)
+ || copy_to_user(lg->mem_base + addr, b, bytes) != 0)
kill_guest(lg, "bad write address %#lx len %u", addr, bytes);
}
-/* (end of memory access helper routines) :*/
-
-static void set_ts(void)
-{
- u32 cr0;
-
- cr0 = read_cr0();
- if (!(cr0 & 8))
- write_cr0(cr0|8);
-}
-
-/*S:010
- * We are getting close to the Switcher.
- *
- * Remember that each CPU has two pages which are visible to the Guest when it
- * runs on that CPU. This has to contain the state for that Guest: we copy the
- * state in just before we run the Guest.
- *
- * Each Guest has "changed" flags which indicate what has changed in the Guest
- * since it last ran. We saw this set in interrupts_and_traps.c and
- * segments.c.
- */
-static void copy_in_guest_info(struct lguest *lg, struct lguest_pages *pages)
-{
- /* Copying all this data can be quite expensive. We usually run the
- * same Guest we ran last time (and that Guest hasn't run anywhere else
- * meanwhile). If that's not the case, we pretend everything in the
- * Guest has changed. */
- if (__get_cpu_var(last_guest) != lg || lg->last_pages != pages) {
- __get_cpu_var(last_guest) = lg;
- lg->last_pages = pages;
- lg->changed = CHANGED_ALL;
- }
-
- /* These copies are pretty cheap, so we do them unconditionally: */
- /* Save the current Host top-level page directory. */
- pages->state.host_cr3 = __pa(current->mm->pgd);
- /* Set up the Guest's page tables to see this CPU's pages (and no
- * other CPU's pages). */
- map_switcher_in_guest(lg, pages);
- /* Set up the two "TSS" members which tell the CPU what stack to use
- * for traps which do directly into the Guest (ie. traps at privilege
- * level 1). */
- pages->state.guest_tss.esp1 = lg->esp1;
- pages->state.guest_tss.ss1 = lg->ss1;
-
- /* Copy direct-to-Guest trap entries. */
- if (lg->changed & CHANGED_IDT)
- copy_traps(lg, pages->state.guest_idt, default_idt_entries);
-
- /* Copy all GDT entries which the Guest can change. */
- if (lg->changed & CHANGED_GDT)
- copy_gdt(lg, pages->state.guest_gdt);
- /* If only the TLS entries have changed, copy them. */
- else if (lg->changed & CHANGED_GDT_TLS)
- copy_gdt_tls(lg, pages->state.guest_gdt);
-
- /* Mark the Guest as unchanged for next time. */
- lg->changed = 0;
-}
-
-/* Finally: the code to actually call into the Switcher to run the Guest. */
-static void run_guest_once(struct lguest *lg, struct lguest_pages *pages)
-{
- /* This is a dummy value we need for GCC's sake. */
- unsigned int clobber;
-
- /* Copy the guest-specific information into this CPU's "struct
- * lguest_pages". */
- copy_in_guest_info(lg, pages);
-
- /* Set the trap number to 256 (impossible value). If we fault while
- * switching to the Guest (bad segment registers or bug), this will
- * cause us to abort the Guest. */
- lg->regs->trapnum = 256;
-
- /* Now: we push the "eflags" register on the stack, then do an "lcall".
- * This is how we change from using the kernel code segment to using
- * the dedicated lguest code segment, as well as jumping into the
- * Switcher.
- *
- * The lcall also pushes the old code segment (KERNEL_CS) onto the
- * stack, then the address of this call. This stack layout happens to
- * exactly match the stack of an interrupt... */
- asm volatile("pushf; lcall *lguest_entry"
- /* This is how we tell GCC that %eax ("a") and %ebx ("b")
- * are changed by this routine. The "=" means output. */
- : "=a"(clobber), "=b"(clobber)
- /* %eax contains the pages pointer. ("0" refers to the
- * 0-th argument above, ie "a"). %ebx contains the
- * physical address of the Guest's top-level page
- * directory. */
- : "0"(pages), "1"(__pa(lg->pgdirs[lg->pgdidx].pgdir))
- /* We tell gcc that all these registers could change,
- * which means we don't have to save and restore them in
- * the Switcher. */
- : "memory", "%edx", "%ecx", "%edi", "%esi");
-}
/*:*/
/*H:030 Let's jump straight to the the main loop which runs the Guest.
@@ -489,22 +175,16 @@ int run_guest(struct lguest *lg, unsigned long __user *user)
{
/* We stop running once the Guest is dead. */
while (!lg->dead) {
- /* We need to initialize this, otherwise gcc complains. It's
- * not (yet) clever enough to see that it's initialized when we
- * need it. */
- unsigned int cr2 = 0; /* Damn gcc */
-
- /* First we run any hypercalls the Guest wants done: either in
- * the hypercall ring in "struct lguest_data", or directly by
- * using int 31 (LGUEST_TRAP_ENTRY). */
- do_hypercalls(lg);
- /* It's possible the Guest did a SEND_DMA hypercall to the
+ /* First we run any hypercalls the Guest wants done. */
+ if (lg->hcall)
+ do_hypercalls(lg);
+
+ /* It's possible the Guest did a NOTIFY hypercall to the
* Launcher, in which case we return from the read() now. */
- if (lg->dma_is_pending) {
- if (put_user(lg->pending_dma, user) ||
- put_user(lg->pending_key, user+1))
+ if (lg->pending_notify) {
+ if (put_user(lg->pending_notify, user))
return -EFAULT;
- return sizeof(unsigned long)*2;
+ return sizeof(lg->pending_notify);
}
/* Check for signals */
@@ -542,144 +222,20 @@ int run_guest(struct lguest *lg, unsigned long __user *user)
* the "Do Not Disturb" sign: */
local_irq_disable();
- /* Remember the awfully-named TS bit? If the Guest has asked
- * to set it we set it now, so we can trap and pass that trap
- * to the Guest if it uses the FPU. */
- if (lg->ts)
- set_ts();
-
- /* SYSENTER is an optimized way of doing system calls. We
- * can't allow it because it always jumps to privilege level 0.
- * A normal Guest won't try it because we don't advertise it in
- * CPUID, but a malicious Guest (or malicious Guest userspace
- * program) could, so we tell the CPU to disable it before
- * running the Guest. */
- if (boot_cpu_has(X86_FEATURE_SEP))
- wrmsr(MSR_IA32_SYSENTER_CS, 0, 0);
-
- /* Now we actually run the Guest. It will pop back out when
- * something interesting happens, and we can examine its
- * registers to see what it was doing. */
- run_guest_once(lg, lguest_pages(raw_smp_processor_id()));
-
- /* The "regs" pointer contains two extra entries which are not
- * really registers: a trap number which says what interrupt or
- * trap made the switcher code come back, and an error code
- * which some traps set. */
-
- /* If the Guest page faulted, then the cr2 register will tell
- * us the bad virtual address. We have to grab this now,
- * because once we re-enable interrupts an interrupt could
- * fault and thus overwrite cr2, or we could even move off to a
- * different CPU. */
- if (lg->regs->trapnum == 14)
- cr2 = read_cr2();
- /* Similarly, if we took a trap because the Guest used the FPU,
- * we have to restore the FPU it expects to see. */
- else if (lg->regs->trapnum == 7)
- math_state_restore();
-
- /* Restore SYSENTER if it's supposed to be on. */
- if (boot_cpu_has(X86_FEATURE_SEP))
- wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
+ /* Actually run the Guest until something happens. */
+ lguest_arch_run_guest(lg);
/* Now we're ready to be interrupted or moved to other CPUs */
local_irq_enable();
- /* OK, so what happened? */
- switch (lg->regs->trapnum) {
- case 13: /* We've intercepted a GPF. */
- /* Check if this was one of those annoying IN or OUT
- * instructions which we need to emulate. If so, we
- * just go back into the Guest after we've done it. */
- if (lg->regs->errcode == 0) {
- if (emulate_insn(lg))
- continue;
- }
- break;
- case 14: /* We've intercepted a page fault. */
- /* The Guest accessed a virtual address that wasn't
- * mapped. This happens a lot: we don't actually set
- * up most of the page tables for the Guest at all when
- * we start: as it runs it asks for more and more, and
- * we set them up as required. In this case, we don't
- * even tell the Guest that the fault happened.
- *
- * The errcode tells whether this was a read or a
- * write, and whether kernel or userspace code. */
- if (demand_page(lg, cr2, lg->regs->errcode))
- continue;
-
- /* OK, it's really not there (or not OK): the Guest
- * needs to know. We write out the cr2 value so it
- * knows where the fault occurred.
- *
- * Note that if the Guest were really messed up, this
- * could happen before it's done the INITIALIZE
- * hypercall, so lg->lguest_data will be NULL, so
- * &lg->lguest_data->cr2 will be address 8. Writing
- * into that address won't hurt the Host at all,
- * though. */
- if (put_user(cr2, &lg->lguest_data->cr2))
- kill_guest(lg, "Writing cr2");
- break;
- case 7: /* We've intercepted a Device Not Available fault. */
- /* If the Guest doesn't want to know, we already
- * restored the Floating Point Unit, so we just
- * continue without telling it. */
- if (!lg->ts)
- continue;
- break;
- case 32 ... 255:
- /* These values mean a real interrupt occurred, in
- * which case the Host handler has already been run.
- * We just do a friendly check if another process
- * should now be run, then fall through to loop
- * around: */
- cond_resched();
- case LGUEST_TRAP_ENTRY: /* Handled at top of loop */
- continue;
- }
-
- /* If we get here, it's a trap the Guest wants to know
- * about. */
- if (deliver_trap(lg, lg->regs->trapnum))
- continue;
-
- /* If the Guest doesn't have a handler (either it hasn't
- * registered any yet, or it's one of the faults we don't let
- * it handle), it dies with a cryptic error message. */
- kill_guest(lg, "unhandled trap %li at %#lx (%#lx)",
- lg->regs->trapnum, lg->regs->eip,
- lg->regs->trapnum == 14 ? cr2 : lg->regs->errcode);
+ /* Now we deal with whatever happened to the Guest. */
+ lguest_arch_handle_trap(lg);
}
+
/* The Guest is dead => "No such file or directory" */
return -ENOENT;
}
-/* Now we can look at each of the routines this calls, in increasing order of
- * complexity: do_hypercalls(), emulate_insn(), maybe_do_interrupt(),
- * deliver_trap() and demand_page(). After all those, we'll be ready to
- * examine the Switcher, and our philosophical understanding of the Host/Guest
- * duality will be complete. :*/
-
-int find_free_guest(void)
-{
- unsigned int i;
- for (i = 0; i < MAX_LGUEST_GUESTS; i++)
- if (!lguests[i].tsk)
- return i;
- return -1;
-}
-
-static void adjust_pge(void *on)
-{
- if (on)
- write_cr4(read_cr4() | X86_CR4_PGE);
- else
- write_cr4(read_cr4() & ~X86_CR4_PGE);
-}
-
/*H:000
* Welcome to the Host!
*
@@ -701,72 +257,50 @@ static int __init init(void)
/* First we put the Switcher up in very high virtual memory. */
err = map_switcher();
if (err)
- return err;
+ goto out;
/* Now we set up the pagetable implementation for the Guests. */
err = init_pagetables(switcher_page, SHARED_SWITCHER_PAGES);
- if (err) {
- unmap_switcher();
- return err;
- }
+ if (err)
+ goto unmap;
- /* The I/O subsystem needs some things initialized. */
- lguest_io_init();
+ /* We might need to reserve an interrupt vector. */
+ err = init_interrupts();
+ if (err)
+ goto free_pgtables;
/* /dev/lguest needs to be registered. */
err = lguest_device_init();
- if (err) {
- free_pagetables();
- unmap_switcher();
- return err;
- }
+ if (err)
+ goto free_interrupts;
- /* Finally, we need to turn off "Page Global Enable". PGE is an
- * optimization where page table entries are specially marked to show
- * they never change. The Host kernel marks all the kernel pages this
- * way because it's always present, even when userspace is running.
- *
- * Lguest breaks this: unbeknownst to the rest of the Host kernel, we
- * switch to the Guest kernel. If you don't disable this on all CPUs,
- * you'll get really weird bugs that you'll chase for two days.
- *
- * I used to turn PGE off every time we switched to the Guest and back
- * on when we return, but that slowed the Switcher down noticibly. */
-
- /* We don't need the complexity of CPUs coming and going while we're
- * doing this. */
- lock_cpu_hotplug();
- if (cpu_has_pge) { /* We have a broader idea of "global". */
- /* Remember that this was originally set (for cleanup). */
- cpu_had_pge = 1;
- /* adjust_pge is a helper function which sets or unsets the PGE
- * bit on its CPU, depending on the argument (0 == unset). */
- on_each_cpu(adjust_pge, (void *)0, 0, 1);
- /* Turn off the feature in the global feature set. */
- clear_bit(X86_FEATURE_PGE, boot_cpu_data.x86_capability);
- }
- unlock_cpu_hotplug();
+ /* Finally we do some architecture-specific setup. */
+ lguest_arch_host_init();
/* All good! */
return 0;
+
+free_interrupts:
+ free_interrupts();
+free_pgtables:
+ free_pagetables();
+unmap:
+ unmap_switcher();
+out:
+ return err;
}
/* Cleaning up is just the same code, backwards. With a little French. */
static void __exit fini(void)
{
lguest_device_remove();
+ free_interrupts();
free_pagetables();
unmap_switcher();
- /* If we had PGE before we started, turn it back on now. */
- lock_cpu_hotplug();
- if (cpu_had_pge) {
- set_bit(X86_FEATURE_PGE, boot_cpu_data.x86_capability);
- /* adjust_pge's argument "1" means set PGE. */
- on_each_cpu(adjust_pge, (void *)1, 0, 1);
- }
- unlock_cpu_hotplug();
+ lguest_arch_host_fini();
}
+/*:*/
/* The Host side of lguest can be a module. This is a nice way for people to
* play with it. */
diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c
index db6caace3b9..9d5184c7c14 100644
--- a/drivers/lguest/hypercalls.c
+++ b/drivers/lguest/hypercalls.c
@@ -25,17 +25,13 @@
#include <linux/mm.h>
#include <asm/page.h>
#include <asm/pgtable.h>
-#include <irq_vectors.h>
#include "lg.h"
-/*H:120 This is the core hypercall routine: where the Guest gets what it
- * wants. Or gets killed. Or, in the case of LHCALL_CRASH, both.
- *
- * Remember from the Guest: %eax == which call to make, and the arguments are
- * packed into %edx, %ebx and %ecx if needed. */
-static void do_hcall(struct lguest *lg, struct lguest_regs *regs)
+/*H:120 This is the core hypercall routine: where the Guest gets what it wants.
+ * Or gets killed. Or, in the case of LHCALL_CRASH, both. */
+static void do_hcall(struct lguest *lg, struct hcall_args *args)
{
- switch (regs->eax) {
+ switch (args->arg0) {
case LHCALL_FLUSH_ASYNC:
/* This call does nothing, except by breaking out of the Guest
* it makes us process all the asynchronous hypercalls. */
@@ -51,7 +47,7 @@ static void do_hcall(struct lguest *lg, struct lguest_regs *regs)
char msg[128];
/* If the lgread fails, it will call kill_guest() itself; the
* kill_guest() with the message will be ignored. */
- lgread(lg, msg, regs->edx, sizeof(msg));
+ __lgread(lg, msg, args->arg1, sizeof(msg));
msg[sizeof(msg)-1] = '\0';
kill_guest(lg, "CRASH: %s", msg);
break;
@@ -59,67 +55,49 @@ static void do_hcall(struct lguest *lg, struct lguest_regs *regs)
case LHCALL_FLUSH_TLB:
/* FLUSH_TLB comes in two flavors, depending on the
* argument: */
- if (regs->edx)
+ if (args->arg1)
guest_pagetable_clear_all(lg);
else
guest_pagetable_flush_user(lg);
break;
- case LHCALL_BIND_DMA:
- /* BIND_DMA really wants four arguments, but it's the only call
- * which does. So the Guest packs the number of buffers and
- * the interrupt number into the final argument, and we decode
- * it here. This can legitimately fail, since we currently
- * place a limit on the number of DMA pools a Guest can have.
- * So we return true or false from this call. */
- regs->eax = bind_dma(lg, regs->edx, regs->ebx,
- regs->ecx >> 8, regs->ecx & 0xFF);
- break;
/* All these calls simply pass the arguments through to the right
* routines. */
- case LHCALL_SEND_DMA:
- send_dma(lg, regs->edx, regs->ebx);
- break;
- case LHCALL_LOAD_GDT:
- load_guest_gdt(lg, regs->edx, regs->ebx);
- break;
- case LHCALL_LOAD_IDT_ENTRY:
- load_guest_idt_entry(lg, regs->edx, regs->ebx, regs->ecx);
- break;
case LHCALL_NEW_PGTABLE:
- guest_new_pagetable(lg, regs->edx);
+ guest_new_pagetable(lg, args->arg1);
break;
case LHCALL_SET_STACK:
- guest_set_stack(lg, regs->edx, regs->ebx, regs->ecx);
+ guest_set_stack(lg, args->arg1, args->arg2, args->arg3);
break;
case LHCALL_SET_PTE:
- guest_set_pte(lg, regs->edx, regs->ebx, mkgpte(regs->ecx));
+ guest_set_pte(lg, args->arg1, args->arg2, __pte(args->arg3));
break;
case LHCALL_SET_PMD:
- guest_set_pmd(lg, regs->edx, regs->ebx);
- break;
- case LHCALL_LOAD_TLS:
- guest_load_tls(lg, regs->edx);
+ guest_set_pmd(lg, args->arg1, args->arg2);
break;
case LHCALL_SET_CLOCKEVENT:
- guest_set_clockevent(lg, regs->edx);
+ guest_set_clockevent(lg, args->arg1);
break;
-
case LHCALL_TS:
/* This sets the TS flag, as we saw used in run_guest(). */
- lg->ts = regs->edx;
+ lg->ts = args->arg1;
break;
case LHCALL_HALT:
/* Similarly, this sets the halted flag for run_guest(). */
lg->halted = 1;
break;
+ case LHCALL_NOTIFY:
+ lg->pending_notify = args->arg1;
+ break;
default:
- kill_guest(lg, "Bad hypercall %li\n", regs->eax);
+ if (lguest_arch_do_hcall(lg, args))
+ kill_guest(lg, "Bad hypercall %li\n", args->arg0);
}
}
+/*:*/
-/* Asynchronous hypercalls are easy: we just look in the array in the Guest's
- * "struct lguest_data" and see if there are any new ones marked "ready".
+/*H:124 Asynchronous hypercalls are easy: we just look in the array in the
+ * Guest's "struct lguest_data" to see if any new ones are marked "ready".
*
* We are careful to do these in order: obviously we respect the order the
* Guest put them in the ring, but we also promise the Guest that they will
@@ -134,10 +112,9 @@ static void do_async_hcalls(struct lguest *lg)
if (copy_from_user(&st, &lg->lguest_data->hcall_status, sizeof(st)))
return;
-
/* We process "struct lguest_data"s hcalls[] ring once. */
for (i = 0; i < ARRAY_SIZE(st); i++) {
- struct lguest_regs regs;
+ struct hcall_args args;
/* We remember where we were up to from last time. This makes
* sure that the hypercalls are done in the order the Guest
* places them in the ring. */
@@ -152,18 +129,16 @@ static void do_async_hcalls(struct lguest *lg)
if (++lg->next_hcall == LHCALL_RING_SIZE)
lg->next_hcall = 0;
- /* We copy the hypercall arguments into a fake register
- * structure. This makes life simple for do_hcall(). */
- if (get_user(regs.eax, &lg->lguest_data->hcalls[n].eax)
- || get_user(regs.edx, &lg->lguest_data->hcalls[n].edx)
- || get_user(regs.ecx, &lg->lguest_data->hcalls[n].ecx)
- || get_user(regs.ebx, &lg->lguest_data->hcalls[n].ebx)) {
+ /* Copy the hypercall arguments into a local copy of
+ * the hcall_args struct. */
+ if (copy_from_user(&args, &lg->lguest_data->hcalls[n],
+ sizeof(struct hcall_args))) {
kill_guest(lg, "Fetching async hypercalls");
break;
}
/* Do the hypercall, same as a normal one. */
- do_hcall(lg, &regs);
+ do_hcall(lg, &args);
/* Mark the hypercall done. */
if (put_user(0xFF, &lg->lguest_data->hcall_status[n])) {
@@ -171,9 +146,9 @@ static void do_async_hcalls(struct lguest *lg)
break;
}
- /* Stop doing hypercalls if we've just done a DMA to the
- * Launcher: it needs to service this first. */
- if (lg->dma_is_pending)
+ /* Stop doing hypercalls if they want to notify the Launcher:
+ * it needs to service this first. */
+ if (lg->pending_notify)
break;
}
}
@@ -182,76 +157,35 @@ static void do_async_hcalls(struct lguest *lg)
* Guest makes a hypercall, we end up here to set things up: */
static void initialize(struct lguest *lg)
{
- u32 tsc_speed;
/* You can't do anything until you're initialized. The Guest knows the
* rules, so we're unforgiving here. */
- if (lg->regs->eax != LHCALL_LGUEST_INIT) {
- kill_guest(lg, "hypercall %li before LGUEST_INIT",
- lg->regs->eax);
+ if (lg->hcall->arg0 != LHCALL_LGUEST_INIT) {
+ kill_guest(lg, "hypercall %li before INIT", lg->hcall->arg0);
return;
}
- /* We insist that the Time Stamp Counter exist and doesn't change with
- * cpu frequency. Some devious chip manufacturers decided that TSC
- * changes could be handled in software. I decided that time going
- * backwards might be good for benchmarks, but it's bad for users.
- *
- * We also insist that the TSC be stable: the kernel detects unreliable
- * TSCs for its own purposes, and we use that here. */
- if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) && !check_tsc_unstable())
- tsc_speed = tsc_khz;
- else
- tsc_speed = 0;
-
- /* The pointer to the Guest's "struct lguest_data" is the only
- * argument. */
- lg->lguest_data = (struct lguest_data __user *)lg->regs->edx;
- /* If we check the address they gave is OK now, we can simply
- * copy_to_user/from_user from now on rather than using lgread/lgwrite.
- * I put this in to show that I'm not immune to writing stupid
- * optimizations. */
- if (!lguest_address_ok(lg, lg->regs->edx, sizeof(*lg->lguest_data))) {
+ if (lguest_arch_init_hypercalls(lg))
kill_guest(lg, "bad guest page %p", lg->lguest_data);
- return;
- }
+
/* The Guest tells us where we're not to deliver interrupts by putting
* the range of addresses into "struct lguest_data". */
if (get_user(lg->noirq_start, &lg->lguest_data->noirq_start)
- || get_user(lg->noirq_end, &lg->lguest_data->noirq_end)
- /* We tell the Guest that it can't use the top 4MB of virtual
- * addresses used by the Switcher. */
- || put_user(4U*1024*1024, &lg->lguest_data->reserve_mem)
- || put_user(tsc_speed, &lg->lguest_data->tsc_khz)
- /* We also give the Guest a unique id, as used in lguest_net.c. */
- || put_user(lg->guestid, &lg->lguest_data->guestid))
+ || get_user(lg->noirq_end, &lg->lguest_data->noirq_end))
kill_guest(lg, "bad guest page %p", lg->lguest_data);
/* We write the current time into the Guest's data page once now. */
write_timestamp(lg);
+ /* page_tables.c will also do some setup. */
+ page_table_guest_data_init(lg);
+
/* This is the one case where the above accesses might have been the
* first write to a Guest page. This may have caused a copy-on-write
* fault, but the Guest might be referring to the old (read-only)
* page. */
guest_pagetable_clear_all(lg);
}
-/* Now we've examined the hypercall code; our Guest can make requests. There
- * is one other way we can do things for the Guest, as we see in
- * emulate_insn(). */
-
-/*H:110 Tricky point: we mark the hypercall as "done" once we've done it.
- * Normally we don't need to do this: the Guest will run again and update the
- * trap number before we come back around the run_guest() loop to
- * do_hypercalls().
- *
- * However, if we are signalled or the Guest sends DMA to the Launcher, that
- * loop will exit without running the Guest. When it comes back it would try
- * to re-run the hypercall. */
-static void clear_hcall(struct lguest *lg)
-{
- lg->regs->trapnum = 255;
-}
/*H:100
* Hypercalls
@@ -261,16 +195,12 @@ static void clear_hcall(struct lguest *lg)
*/
void do_hypercalls(struct lguest *lg)
{
- /* Not initialized yet? */
+ /* Not initialized yet? This hypercall must do it. */
if (unlikely(!lg->lguest_data)) {
- /* Did the Guest make a hypercall? We might have come back for
- * some other reason (an interrupt, a different trap). */
- if (lg->regs->trapnum == LGUEST_TRAP_ENTRY) {
- /* Set up the "struct lguest_data" */
- initialize(lg);
- /* The hypercall is done. */
- clear_hcall(lg);
- }
+ /* Set up the "struct lguest_data" */
+ initialize(lg);
+ /* Hcall is done. */
+ lg->hcall = NULL;
return;
}
@@ -280,12 +210,21 @@ void do_hypercalls(struct lguest *lg)
do_async_hcalls(lg);
/* If we stopped reading the hypercall ring because the Guest did a
- * SEND_DMA to the Launcher, we want to return now. Otherwise if the
- * Guest asked us to do a hypercall, we do it. */
- if (!lg->dma_is_pending && lg->regs->trapnum == LGUEST_TRAP_ENTRY) {
- do_hcall(lg, lg->regs);
- /* The hypercall is done. */
- clear_hcall(lg);
+ * NOTIFY to the Launcher, we want to return now. Otherwise we do
+ * the hypercall. */
+ if (!lg->pending_notify) {
+ do_hcall(lg, lg->hcall);
+ /* Tricky point: we reset the hcall pointer to mark the
+ * hypercall as "done". We use the hcall pointer rather than
+ * the trap number to indicate a hypercall is pending.
+ * Normally it doesn't matter: the Guest will run again and
+ * update the trap number before we come back here.
+ *
+ * However, if we are signalled or the Guest sends DMA to the
+ * Launcher, the run_guest() loop will exit without running the
+ * Guest. When it comes back it would try to re-run the
+ * hypercall. */
+ lg->hcall = NULL;
}
}
@@ -295,6 +234,6 @@ void write_timestamp(struct lguest *lg)
{
struct timespec now;
ktime_get_real_ts(&now);
- if (put_user(now, &lg->lguest_data->time))
+ if (copy_to_user(&lg->lguest_data->time, &now, sizeof(struct timespec)))
kill_guest(lg, "Writing timestamp");
}
diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c
index 39731232d82..82966982cb3 100644
--- a/drivers/lguest/interrupts_and_traps.c
+++ b/drivers/lguest/interrupts_and_traps.c
@@ -12,8 +12,14 @@
* them first, so we also have a way of "reflecting" them into the Guest as if
* they had been delivered to it directly. :*/
#include <linux/uaccess.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
#include "lg.h"
+/* Allow Guests to use a non-128 (ie. non-Linux) syscall trap. */
+static unsigned int syscall_vector = SYSCALL_VECTOR;
+module_param(syscall_vector, uint, 0444);
+
/* The address of the interrupt handler is split into two bits: */
static unsigned long idt_address(u32 lo, u32 hi)
{
@@ -39,7 +45,7 @@ static void push_guest_stack(struct lguest *lg, unsigned long *gstack, u32 val)
{
/* Stack grows upwards: move stack then write value. */
*gstack -= 4;
- lgwrite_u32(lg, *gstack, val);
+ lgwrite(lg, *gstack, u32, val);
}
/*H:210 The set_guest_interrupt() routine actually delivers the interrupt or
@@ -56,8 +62,9 @@ static void push_guest_stack(struct lguest *lg, unsigned long *gstack, u32 val)
* it). */
static void set_guest_interrupt(struct lguest *lg, u32 lo, u32 hi, int has_err)
{
- unsigned long gstack;
+ unsigned long gstack, origstack;
u32 eflags, ss, irq_enable;
+ unsigned long virtstack;
/* There are two cases for interrupts: one where the Guest is already
* in the kernel, and a more complex one where the Guest is in
@@ -65,8 +72,10 @@ static void set_guest_interrupt(struct lguest *lg, u32 lo, u32 hi, int has_err)
if ((lg->regs->ss&0x3) != GUEST_PL) {
/* The Guest told us their kernel stack with the SET_STACK
* hypercall: both the virtual address and the segment */
- gstack = guest_pa(lg, lg->esp1);
+ virtstack = lg->esp1;
ss = lg->ss1;
+
+ origstack = gstack = guest_pa(lg, virtstack);
/* We push the old stack segment and pointer onto the new
* stack: when the Guest does an "iret" back from the interrupt
* handler the CPU will notice they're dropping privilege
@@ -75,8 +84,10 @@ static void set_guest_interrupt(struct lguest *lg, u32 lo, u32 hi, int has_err)
push_guest_stack(lg, &gstack, lg->regs->esp);
} else {
/* We're staying on the same Guest (kernel) stack. */
- gstack = guest_pa(lg, lg->regs->esp);
+ virtstack = lg->regs->esp;
ss = lg->regs->ss;
+
+ origstack = gstack = guest_pa(lg, virtstack);
}
/* Remember that we never let the Guest actually disable interrupts, so
@@ -102,7 +113,7 @@ static void set_guest_interrupt(struct lguest *lg, u32 lo, u32 hi, int has_err)
/* Now we've pushed all the old state, we change the stack, the code
* segment and the address to execute. */
lg->regs->ss = ss;
- lg->regs->esp = gstack + lg->page_offset;
+ lg->regs->esp = virtstack + (gstack - origstack);
lg->regs->cs = (__KERNEL_CS|GUEST_PL);
lg->regs->eip = idt_address(lo, hi);
@@ -165,7 +176,7 @@ void maybe_do_interrupt(struct lguest *lg)
/* Look at the IDT entry the Guest gave us for this interrupt. The
* first 32 (FIRST_EXTERNAL_VECTOR) entries are for traps, so we skip
* over them. */
- idt = &lg->idt[FIRST_EXTERNAL_VECTOR+irq];
+ idt = &lg->arch.idt[FIRST_EXTERNAL_VECTOR+irq];
/* If they don't have a handler (yet?), we just ignore it */
if (idt_present(idt->a, idt->b)) {
/* OK, mark it no longer pending and deliver it. */
@@ -183,6 +194,47 @@ void maybe_do_interrupt(struct lguest *lg)
* timer interrupt. */
write_timestamp(lg);
}
+/*:*/
+
+/* Linux uses trap 128 for system calls. Plan9 uses 64, and Ron Minnich sent
+ * me a patch, so we support that too. It'd be a big step for lguest if half
+ * the Plan 9 user base were to start using it.
+ *
+ * Actually now I think of it, it's possible that Ron *is* half the Plan 9
+ * userbase. Oh well. */
+static bool could_be_syscall(unsigned int num)
+{
+ /* Normal Linux SYSCALL_VECTOR or reserved vector? */
+ return num == SYSCALL_VECTOR || num == syscall_vector;
+}
+
+/* The syscall vector it wants must be unused by Host. */
+bool check_syscall_vector(struct lguest *lg)
+{
+ u32 vector;
+
+ if (get_user(vector, &lg->lguest_data->syscall_vec))
+ return false;
+
+ return could_be_syscall(vector);
+}
+
+int init_interrupts(void)
+{
+ /* If they want some strange system call vector, reserve it now */
+ if (syscall_vector != SYSCALL_VECTOR
+ && test_and_set_bit(syscall_vector, used_vectors)) {
+ printk("lg: couldn't reserve syscall %u\n", syscall_vector);
+ return -EBUSY;
+ }
+ return 0;
+}
+
+void free_interrupts(void)
+{
+ if (syscall_vector != SYSCALL_VECTOR)
+ clear_bit(syscall_vector, used_vectors);
+}
/*H:220 Now we've got the routines to deliver interrupts, delivering traps
* like page fault is easy. The only trick is that Intel decided that some
@@ -197,14 +249,14 @@ int deliver_trap(struct lguest *lg, unsigned int num)
{
/* Trap numbers are always 8 bit, but we set an impossible trap number
* for traps inside the Switcher, so check that here. */
- if (num >= ARRAY_SIZE(lg->idt))
+ if (num >= ARRAY_SIZE(lg->arch.idt))
return 0;
/* Early on the Guest hasn't set the IDT entries (or maybe it put a
* bogus one in): if we fail here, the Guest will be killed. */
- if (!idt_present(lg->idt[num].a, lg->idt[num].b))
+ if (!idt_present(lg->arch.idt[num].a, lg->arch.idt[num].b))
return 0;
- set_guest_interrupt(lg, lg->idt[num].a, lg->idt[num].b, has_err(num));
+ set_guest_interrupt(lg, lg->arch.idt[num].a, lg->arch.idt[num].b, has_err(num));
return 1;
}
@@ -218,28 +270,20 @@ int deliver_trap(struct lguest *lg, unsigned int num)
* system calls down from 1750ns to 270ns. Plus, if lguest didn't do it, all
* the other hypervisors would tease it.
*
- * This routine determines if a trap can be delivered directly. */
-static int direct_trap(const struct lguest *lg,
- const struct desc_struct *trap,
- unsigned int num)
+ * This routine indicates if a particular trap number could be delivered
+ * directly. */
+static int direct_trap(unsigned int num)
{
/* Hardware interrupts don't go to the Guest at all (except system
* call). */
- if (num >= FIRST_EXTERNAL_VECTOR && num != SYSCALL_VECTOR)
+ if (num >= FIRST_EXTERNAL_VECTOR && !could_be_syscall(num))
return 0;
/* The Host needs to see page faults (for shadow paging and to save the
* fault address), general protection faults (in/out emulation) and
* device not available (TS handling), and of course, the hypercall
* trap. */
- if (num == 14 || num == 13 || num == 7 || num == LGUEST_TRAP_ENTRY)
- return 0;
-
- /* Only trap gates (type 15) can go direct to the Guest. Interrupt
- * gates (type 14) disable interrupts as they are entered, which we
- * never let the Guest do. Not present entries (type 0x0) also can't
- * go direct, of course 8) */
- return idt_type(trap->a, trap->b) == 0xF;
+ return num != 14 && num != 13 && num != 7 && num != LGUEST_TRAP_ENTRY;
}
/*:*/
@@ -348,15 +392,11 @@ void load_guest_idt_entry(struct lguest *lg, unsigned int num, u32 lo, u32 hi)
* to copy this again. */
lg->changed |= CHANGED_IDT;
- /* The IDT which we keep in "struct lguest" only contains 32 entries
- * for the traps and LGUEST_IRQS (32) entries for interrupts. We
- * ignore attempts to set handlers for higher interrupt numbers, except
- * for the system call "interrupt" at 128: we have a special IDT entry
- * for that. */
- if (num < ARRAY_SIZE(lg->idt))
- set_trap(lg, &lg->idt[num], num, lo, hi);
- else if (num == SYSCALL_VECTOR)
- set_trap(lg, &lg->syscall_idt, num, lo, hi);
+ /* Check that the Guest doesn't try to step outside the bounds. */
+ if (num >= ARRAY_SIZE(lg->arch.idt))
+ kill_guest(lg, "Setting idt entry %u", num);
+ else
+ set_trap(lg, &lg->arch.idt[num], num, lo, hi);
}
/* The default entry for each interrupt points into the Switcher routines which
@@ -399,20 +439,21 @@ void copy_traps(const struct lguest *lg, struct desc_struct *idt,
/* We can simply copy the direct traps, otherwise we use the default
* ones in the Switcher: they will return to the Host. */
- for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++) {
- if (direct_trap(lg, &lg->idt[i], i))
- idt[i] = lg->idt[i];
+ for (i = 0; i < ARRAY_SIZE(lg->arch.idt); i++) {
+ /* If no Guest can ever override this trap, leave it alone. */
+ if (!direct_trap(i))
+ continue;
+
+ /* Only trap gates (type 15) can go direct to the Guest.
+ * Interrupt gates (type 14) disable interrupts as they are
+ * entered, which we never let the Guest do. Not present
+ * entries (type 0x0) also can't go direct, of course. */
+ if (idt_type(lg->arch.idt[i].a, lg->arch.idt[i].b) == 0xF)
+ idt[i] = lg->arch.idt[i];
else
+ /* Reset it to the default. */
default_idt_entry(&idt[i], i, def[i]);
}
-
- /* Don't forget the system call trap! The IDT entries for other
- * interupts never change, so no need to copy them. */
- i = SYSCALL_VECTOR;
- if (direct_trap(lg, &lg->syscall_idt, i))
- idt[i] = lg->syscall_idt;
- else
- default_idt_entry(&idt[i], i, def[i]);
}
void guest_set_clockevent(struct lguest *lg, unsigned long delta)
diff --git a/drivers/lguest/io.c b/drivers/lguest/io.c
deleted file mode 100644
index ea68613b43f..00000000000
--- a/drivers/lguest/io.c
+++ /dev/null
@@ -1,626 +0,0 @@
-/*P:300 The I/O mechanism in lguest is simple yet flexible, allowing the Guest
- * to talk to the Launcher or directly to another Guest. It uses familiar
- * concepts of DMA and interrupts, plus some neat code stolen from
- * futexes... :*/
-
-/* Copyright (C) 2006 Rusty Russell IBM Corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
- */
-#include <linux/types.h>
-#include <linux/futex.h>
-#include <linux/jhash.h>
-#include <linux/mm.h>
-#include <linux/highmem.h>
-#include <linux/uaccess.h>
-#include "lg.h"
-
-/*L:300
- * I/O
- *
- * Getting data in and out of the Guest is quite an art. There are numerous
- * ways to do it, and they all suck differently. We try to keep things fairly
- * close to "real" hardware so our Guest's drivers don't look like an alien
- * visitation in the middle of the Linux code, and yet make sure that Guests
- * can talk directly to other Guests, not just the Launcher.
- *
- * To do this, the Guest gives us a key when it binds or sends DMA buffers.
- * The key corresponds to a "physical" address inside the Guest (ie. a virtual
- * address inside the Launcher process). We don't, however, use this key
- * directly.
- *
- * We want Guests which share memory to be able to DMA to each other: two
- * Launchers can mmap memory the same file, then the Guests can communicate.
- * Fortunately, the futex code provides us with a way to get a "union
- * futex_key" corresponding to the memory lying at a virtual address: if the
- * two processes share memory, the "union futex_key" for that memory will match
- * even if the memory is mapped at different addresses in each. So we always
- * convert the keys to "union futex_key"s to compare them.
- *
- * Before we dive into this though, we need to look at another set of helper
- * routines used throughout the Host kernel code to access Guest memory.
- :*/
-static struct list_head dma_hash[61];
-
-/* An unfortunate side effect of the Linux double-linked list implementation is
- * that there's no good way to statically initialize an array of linked
- * lists. */
-void lguest_io_init(void)
-{
- unsigned int i;
-
- for (i = 0; i < ARRAY_SIZE(dma_hash); i++)
- INIT_LIST_HEAD(&dma_hash[i]);
-}
-
-/* FIXME: allow multi-page lengths. */
-static int check_dma_list(struct lguest *lg, const struct lguest_dma *dma)
-{
- unsigned int i;
-
- for (i = 0; i < LGUEST_MAX_DMA_SECTIONS; i++) {
- if (!dma->len[i])
- return 1;
- if (!lguest_address_ok(lg, dma->addr[i], dma->len[i]))
- goto kill;
- if (dma->len[i] > PAGE_SIZE)
- goto kill;
- /* We could do over a page, but is it worth it? */
- if ((dma->addr[i] % PAGE_SIZE) + dma->len[i] > PAGE_SIZE)
- goto kill;
- }
- return 1;
-
-kill:
- kill_guest(lg, "bad DMA entry: %u@%#lx", dma->len[i], dma->addr[i]);
- return 0;
-}
-
-/*L:330 This is our hash function, using the wonderful Jenkins hash.
- *
- * The futex key is a union with three parts: an unsigned long word, a pointer,
- * and an int "offset". We could use jhash_2words() which takes three u32s.
- * (Ok, the hash functions are great: the naming sucks though).
- *
- * It's nice to be portable to 64-bit platforms, so we use the more generic
- * jhash2(), which takes an array of u32, the number of u32s, and an initial
- * u32 to roll in. This is uglier, but breaks down to almost the same code on
- * 32-bit platforms like this one.
- *
- * We want a position in the array, so we modulo ARRAY_SIZE(dma_hash) (ie. 61).
- */
-static unsigned int hash(const union futex_key *key)
-{
- return jhash2((u32*)&key->both.word,
- (sizeof(key->both.word)+sizeof(key->both.ptr))/4,
- key->both.offset)
- % ARRAY_SIZE(dma_hash);
-}
-
-/* This is a convenience routine to compare two keys. It's a much bemoaned C
- * weakness that it doesn't allow '==' on structures or unions, so we have to
- * open-code it like this. */
-static inline int key_eq(const union futex_key *a, const union futex_key *b)
-{
- return (a->both.word == b->both.word
- && a->both.ptr == b->both.ptr
- && a->both.offset == b->both.offset);
-}
-
-/*L:360 OK, when we need to actually free up a Guest's DMA array we do several
- * things, so we have a convenient function to do it.
- *
- * The caller must hold a read lock on dmainfo owner's current->mm->mmap_sem
- * for the drop_futex_key_refs(). */
-static void unlink_dma(struct lguest_dma_info *dmainfo)
-{
- /* You locked this too, right? */
- BUG_ON(!mutex_is_locked(&lguest_lock));
- /* This is how we know that the entry is free. */
- dmainfo->interrupt = 0;
- /* Remove it from the hash table. */
- list_del(&dmainfo->list);
- /* Drop the references we were holding (to the inode or mm). */
- drop_futex_key_refs(&dmainfo->key);
-}
-
-/*L:350 This is the routine which we call when the Guest asks to unregister a
- * DMA array attached to a given key. Returns true if the array was found. */
-static int unbind_dma(struct lguest *lg,
- const union futex_key *key,
- unsigned long dmas)
-{
- int i, ret = 0;
-
- /* We don't bother with the hash table, just look through all this
- * Guest's DMA arrays. */
- for (i = 0; i < LGUEST_MAX_DMA; i++) {
- /* In theory it could have more than one array on the same key,
- * or one array on multiple keys, so we check both */
- if (key_eq(key, &lg->dma[i].key) && dmas == lg->dma[i].dmas) {
- unlink_dma(&lg->dma[i]);
- ret = 1;
- break;
- }
- }
- return ret;
-}
-
-/*L:340 BIND_DMA: this is the hypercall which sets up an array of "struct
- * lguest_dma" for receiving I/O.
- *
- * The Guest wants to bind an array of "struct lguest_dma"s to a particular key
- * to receive input. This only happens when the Guest is setting up a new
- * device, so it doesn't have to be very fast.
- *
- * It returns 1 on a successful registration (it can fail if we hit the limit
- * of registrations for this Guest).
- */
-int bind_dma(struct lguest *lg,
- unsigned long ukey, unsigned long dmas, u16 numdmas, u8 interrupt)
-{
- unsigned int i;
- int ret = 0;
- union futex_key key;
- /* Futex code needs the mmap_sem. */
- struct rw_semaphore *fshared = &current->mm->mmap_sem;
-
- /* Invalid interrupt? (We could kill the guest here). */
- if (interrupt >= LGUEST_IRQS)
- return 0;
-
- /* We need to grab the Big Lguest Lock, because other Guests may be
- * trying to look through this Guest's DMAs to send something while
- * we're doing this. */
- mutex_lock(&lguest_lock);
- down_read(fshared);
- if (get_futex_key((u32 __user *)ukey, fshared, &key) != 0) {
- kill_guest(lg, "bad dma key %#lx", ukey);
- goto unlock;
- }
-
- /* We want to keep this key valid once we drop mmap_sem, so we have to
- * hold a reference. */
- get_futex_key_refs(&key);
-
- /* If the Guest specified an interrupt of 0, that means they want to
- * unregister this array of "struct lguest_dma"s. */
- if (interrupt == 0)
- ret = unbind_dma(lg, &key, dmas);
- else {
- /* Look through this Guest's dma array for an unused entry. */
- for (i = 0; i < LGUEST_MAX_DMA; i++) {
- /* If the interrupt is non-zero, the entry is already
- * used. */
- if (lg->dma[i].interrupt)
- continue;
-
- /* OK, a free one! Fill on our details. */
- lg->dma[i].dmas = dmas;
- lg->dma[i].num_dmas = numdmas;
- lg->dma[i].next_dma = 0;
- lg->dma[i].key = key;
- lg->dma[i].guestid = lg->guestid;
- lg->dma[i].interrupt = interrupt;
-
- /* Now we add it to the hash table: the position
- * depends on the futex key that we got. */
- list_add(&lg->dma[i].list, &dma_hash[hash(&key)]);
- /* Success! */
- ret = 1;
- goto unlock;
- }
- }
- /* If we didn't find a slot to put the key in, drop the reference
- * again. */
- drop_futex_key_refs(&key);
-unlock:
- /* Unlock and out. */
- up_read(fshared);
- mutex_unlock(&lguest_lock);
- return ret;
-}
-
-/*L:385 Note that our routines to access a different Guest's memory are called
- * lgread_other() and lgwrite_other(): these names emphasize that they are only
- * used when the Guest is *not* the current Guest.
- *
- * The interface for copying from another process's memory is called
- * access_process_vm(), with a final argument of 0 for a read, and 1 for a
- * write.
- *
- * We need lgread_other() to read the destination Guest's "struct lguest_dma"
- * array. */
-static int lgread_other(struct lguest *lg,
- void *buf, u32 addr, unsigned bytes)
-{
- if (!lguest_address_ok(lg, addr, bytes)
- || access_process_vm(lg->tsk, addr, buf, bytes, 0) != bytes) {
- memset(buf, 0, bytes);
- kill_guest(lg, "bad address in registered DMA struct");
- return 0;
- }
- return 1;
-}
-
-/* "lgwrite()" to another Guest: used to update the destination "used_len" once
- * we've transferred data into the buffer. */
-static int lgwrite_other(struct lguest *lg, u32 addr,
- const void *buf, unsigned bytes)
-{
- if (!lguest_address_ok(lg, addr, bytes)
- || (access_process_vm(lg->tsk, addr, (void *)buf, bytes, 1)
- != bytes)) {
- kill_guest(lg, "bad address writing to registered DMA");
- return 0;
- }
- return 1;
-}
-
-/*L:400 This is the generic engine which copies from a source "struct
- * lguest_dma" from this Guest into another Guest's "struct lguest_dma". The
- * destination Guest's pages have already been mapped, as contained in the
- * pages array.
- *
- * If you're wondering if there's a nice "copy from one process to another"
- * routine, so was I. But Linux isn't really set up to copy between two
- * unrelated processes, so we have to write it ourselves.
- */
-static u32 copy_data(struct lguest *srclg,
- const struct lguest_dma *src,
- const struct lguest_dma *dst,
- struct page *pages[])
-{
- unsigned int totlen, si, di, srcoff, dstoff;
- void *maddr = NULL;
-
- /* We return the total length transferred. */
- totlen = 0;
-
- /* We keep indexes into the source and destination "struct lguest_dma",
- * and an offset within each region. */
- si = di = 0;
- srcoff = dstoff = 0;
-
- /* We loop until the source or destination is exhausted. */
- while (si < LGUEST_MAX_DMA_SECTIONS && src->len[si]
- && di < LGUEST_MAX_DMA_SECTIONS && dst->len[di]) {
- /* We can only transfer the rest of the src buffer, or as much
- * as will fit into the destination buffer. */
- u32 len = min(src->len[si] - srcoff, dst->len[di] - dstoff);
-
- /* For systems using "highmem" we need to use kmap() to access
- * the page we want. We often use the same page over and over,
- * so rather than kmap() it on every loop, we set the maddr
- * pointer to NULL when we need to move to the next
- * destination page. */
- if (!maddr)
- maddr = kmap(pages[di]);
-
- /* Copy directly from (this Guest's) source address to the
- * destination Guest's kmap()ed buffer. Note that maddr points
- * to the start of the page: we need to add the offset of the
- * destination address and offset within the buffer. */
-
- /* FIXME: This is not completely portable. I looked at
- * copy_to_user_page(), and some arch's seem to need special
- * flushes. x86 is fine. */
- if (copy_from_user(maddr + (dst->addr[di] + dstoff)%PAGE_SIZE,
- (void __user *)src->addr[si], len) != 0) {
- /* If a copy failed, it's the source's fault. */
- kill_guest(srclg, "bad address in sending DMA");
- totlen = 0;
- break;
- }
-
- /* Increment the total and src & dst offsets */
- totlen += len;
- srcoff += len;
- dstoff += len;
-
- /* Presumably we reached the end of the src or dest buffers: */
- if (srcoff == src->len[si]) {
- /* Move to the next buffer at offset 0 */
- si++;
- srcoff = 0;
- }
- if (dstoff == dst->len[di]) {
- /* We need to unmap that destination page and reset
- * maddr ready for the next one. */
- kunmap(pages[di]);
- maddr = NULL;
- di++;
- dstoff = 0;
- }
- }
-
- /* If we still had a page mapped at the end, unmap now. */
- if (maddr)
- kunmap(pages[di]);
-
- return totlen;
-}
-
-/*L:390 This is how we transfer a "struct lguest_dma" from the source Guest
- * (the current Guest which called SEND_DMA) to another Guest. */
-static u32 do_dma(struct lguest *srclg, const struct lguest_dma *src,
- struct lguest *dstlg, const struct lguest_dma *dst)
-{
- int i;
- u32 ret;
- struct page *pages[LGUEST_MAX_DMA_SECTIONS];
-
- /* We check that both source and destination "struct lguest_dma"s are
- * within the bounds of the source and destination Guests */
- if (!check_dma_list(dstlg, dst) || !check_dma_list(srclg, src))
- return 0;
-
- /* We need to map the pages which correspond to each parts of
- * destination buffer. */
- for (i = 0; i < LGUEST_MAX_DMA_SECTIONS; i++) {
- if (dst->len[i] == 0)
- break;
- /* get_user_pages() is a complicated function, especially since
- * we only want a single page. But it works, and returns the
- * number of pages. Note that we're holding the destination's
- * mmap_sem, as get_user_pages() requires. */
- if (get_user_pages(dstlg->tsk, dstlg->mm,
- dst->addr[i], 1, 1, 1, pages+i, NULL)
- != 1) {
- /* This means the destination gave us a bogus buffer */
- kill_guest(dstlg, "Error mapping DMA pages");
- ret = 0;
- goto drop_pages;
- }
- }
-
- /* Now copy the data until we run out of src or dst. */
- ret = copy_data(srclg, src, dst, pages);
-
-drop_pages:
- while (--i >= 0)
- put_page(pages[i]);
- return ret;
-}
-
-/*L:380 Transferring data from one Guest to another is not as simple as I'd
- * like. We've found the "struct lguest_dma_info" bound to the same address as
- * the send, we need to copy into it.
- *
- * This function returns true if the destination array was empty. */
-static int dma_transfer(struct lguest *srclg,
- unsigned long udma,
- struct lguest_dma_info *dst)
-{
- struct lguest_dma dst_dma, src_dma;
- struct lguest *dstlg;
- u32 i, dma = 0;
-
- /* From the "struct lguest_dma_info" we found in the hash, grab the
- * Guest. */
- dstlg = &lguests[dst->guestid];
- /* Read in the source "struct lguest_dma" handed to SEND_DMA. */
- lgread(srclg, &src_dma, udma, sizeof(src_dma));
-
- /* We need the destination's mmap_sem, and we already hold the source's
- * mmap_sem for the futex key lookup. Normally this would suggest that
- * we could deadlock if the destination Guest was trying to send to
- * this source Guest at the same time, which is another reason that all
- * I/O is done under the big lguest_lock. */
- down_read(&dstlg->mm->mmap_sem);
-
- /* Look through the destination DMA array for an available buffer. */
- for (i = 0; i < dst->num_dmas; i++) {
- /* We keep a "next_dma" pointer which often helps us avoid
- * looking at lots of previously-filled entries. */
- dma = (dst->next_dma + i) % dst->num_dmas;
- if (!lgread_other(dstlg, &dst_dma,
- dst->dmas + dma * sizeof(struct lguest_dma),
- sizeof(dst_dma))) {
- goto fail;
- }
- if (!dst_dma.used_len)
- break;
- }
-
- /* If we found a buffer, we do the actual data copy. */
- if (i != dst->num_dmas) {
- unsigned long used_lenp;
- unsigned int ret;
-
- ret = do_dma(srclg, &src_dma, dstlg, &dst_dma);
- /* Put used length in the source "struct lguest_dma"'s used_len
- * field. It's a little tricky to figure out where that is,
- * though. */
- lgwrite_u32(srclg,
- udma+offsetof(struct lguest_dma, used_len), ret);
- /* Tranferring 0 bytes is OK if the source buffer was empty. */
- if (ret == 0 && src_dma.len[0] != 0)
- goto fail;
-
- /* The destination Guest might be running on a different CPU:
- * we have to make sure that it will see the "used_len" field
- * change to non-zero *after* it sees the data we copied into
- * the buffer. Hence a write memory barrier. */
- wmb();
- /* Figuring out where the destination's used_len field for this
- * "struct lguest_dma" in the array is also a little ugly. */
- used_lenp = dst->dmas
- + dma * sizeof(struct lguest_dma)
- + offsetof(struct lguest_dma, used_len);
- lgwrite_other(dstlg, used_lenp, &ret, sizeof(ret));
- /* Move the cursor for next time. */
- dst->next_dma++;
- }
- up_read(&dstlg->mm->mmap_sem);
-
- /* We trigger the destination interrupt, even if the destination was
- * empty and we didn't transfer anything: this gives them a chance to
- * wake up and refill. */
- set_bit(dst->interrupt, dstlg->irqs_pending);
- /* Wake up the destination process. */
- wake_up_process(dstlg->tsk);
- /* If we passed the last "struct lguest_dma", the receive had no
- * buffers left. */
- return i == dst->num_dmas;
-
-fail:
- up_read(&dstlg->mm->mmap_sem);
- return 0;
-}
-
-/*L:370 This is the counter-side to the BIND_DMA hypercall; the SEND_DMA
- * hypercall. We find out who's listening, and send to them. */
-void send_dma(struct lguest *lg, unsigned long ukey, unsigned long udma)
-{
- union futex_key key;
- int empty = 0;
- struct rw_semaphore *fshared = &current->mm->mmap_sem;
-
-again:
- mutex_lock(&lguest_lock);
- down_read(fshared);
- /* Get the futex key for the key the Guest gave us */
- if (get_futex_key((u32 __user *)ukey, fshared, &key) != 0) {
- kill_guest(lg, "bad sending DMA key");
- goto unlock;
- }
- /* Since the key must be a multiple of 4, the futex key uses the lower
- * bit of the "offset" field (which would always be 0) to indicate a
- * mapping which is shared with other processes (ie. Guests). */
- if (key.shared.offset & 1) {
- struct lguest_dma_info *i;
- /* Look through the hash for other Guests. */
- list_for_each_entry(i, &dma_hash[hash(&key)], list) {
- /* Don't send to ourselves. */
- if (i->guestid == lg->guestid)
- continue;
- if (!key_eq(&key, &i->key))
- continue;
-
- /* If dma_transfer() tells us the destination has no
- * available buffers, we increment "empty". */
- empty += dma_transfer(lg, udma, i);
- break;
- }
- /* If the destination is empty, we release our locks and
- * give the destination Guest a brief chance to restock. */
- if (empty == 1) {
- /* Give any recipients one chance to restock. */
- up_read(&current->mm->mmap_sem);
- mutex_unlock(&lguest_lock);
- /* Next time, we won't try again. */
- empty++;
- goto again;
- }
- } else {
- /* Private mapping: Guest is sending to its Launcher. We set
- * the "dma_is_pending" flag so that the main loop will exit
- * and the Launcher's read() from /dev/lguest will return. */
- lg->dma_is_pending = 1;
- lg->pending_dma = udma;
- lg->pending_key = ukey;
- }
-unlock:
- up_read(fshared);
- mutex_unlock(&lguest_lock);
-}
-/*:*/
-
-void release_all_dma(struct lguest *lg)
-{
- unsigned int i;
-
- BUG_ON(!mutex_is_locked(&lguest_lock));
-
- down_read(&lg->mm->mmap_sem);
- for (i = 0; i < LGUEST_MAX_DMA; i++) {
- if (lg->dma[i].interrupt)
- unlink_dma(&lg->dma[i]);
- }
- up_read(&lg->mm->mmap_sem);
-}
-
-/*M:007 We only return a single DMA buffer to the Launcher, but it would be
- * more efficient to return a pointer to the entire array of DMA buffers, which
- * it can cache and choose one whenever it wants.
- *
- * Currently the Launcher uses a write to /dev/lguest, and the return value is
- * the address of the DMA structure with the interrupt number placed in
- * dma->used_len. If we wanted to return the entire array, we need to return
- * the address, array size and interrupt number: this seems to require an
- * ioctl(). :*/
-
-/*L:320 This routine looks for a DMA buffer registered by the Guest on the
- * given key (using the BIND_DMA hypercall). */
-unsigned long get_dma_buffer(struct lguest *lg,
- unsigned long ukey, unsigned long *interrupt)
-{
- unsigned long ret = 0;
- union futex_key key;
- struct lguest_dma_info *i;
- struct rw_semaphore *fshared = &current->mm->mmap_sem;
-
- /* Take the Big Lguest Lock to stop other Guests sending this Guest DMA
- * at the same time. */
- mutex_lock(&lguest_lock);
- /* To match between Guests sharing the same underlying memory we steal
- * code from the futex infrastructure. This requires that we hold the
- * "mmap_sem" for our process (the Launcher), and pass it to the futex
- * code. */
- down_read(fshared);
-
- /* This can fail if it's not a valid address, or if the address is not
- * divisible by 4 (the futex code needs that, we don't really). */
- if (get_futex_key((u32 __user *)ukey, fshared, &key) != 0) {
- kill_guest(lg, "bad registered DMA buffer");
- goto unlock;
- }
- /* Search the hash table for matching entries (the Launcher can only
- * send to its own Guest for the moment, so the entry must be for this
- * Guest) */
- list_for_each_entry(i, &dma_hash[hash(&key)], list) {
- if (key_eq(&key, &i->key) && i->guestid == lg->guestid) {
- unsigned int j;
- /* Look through the registered DMA array for an
- * available buffer. */
- for (j = 0; j < i->num_dmas; j++) {
- struct lguest_dma dma;
-
- ret = i->dmas + j * sizeof(struct lguest_dma);
- lgread(lg, &dma, ret, sizeof(dma));
- if (dma.used_len == 0)
- break;
- }
- /* Store the interrupt the Guest wants when the buffer
- * is used. */
- *interrupt = i->interrupt;
- break;
- }
- }
-unlock:
- up_read(fshared);
- mutex_unlock(&lguest_lock);
- return ret;
-}
-/*:*/
-
-/*L:410 This really has completed the Launcher. Not only have we now finished
- * the longest chapter in our journey, but this also means we are over halfway
- * through!
- *
- * Enough prevaricating around the bush: it is time for us to dive into the
- * core of the Host, in "make Host".
- */
diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h
index 64f0abed317..d9144beca82 100644
--- a/drivers/lguest/lg.h
+++ b/drivers/lguest/lg.h
@@ -1,119 +1,25 @@
#ifndef _LGUEST_H
#define _LGUEST_H
-#include <asm/desc.h>
-
-#define GDT_ENTRY_LGUEST_CS 10
-#define GDT_ENTRY_LGUEST_DS 11
-#define LGUEST_CS (GDT_ENTRY_LGUEST_CS * 8)
-#define LGUEST_DS (GDT_ENTRY_LGUEST_DS * 8)
-
#ifndef __ASSEMBLY__
#include <linux/types.h>
#include <linux/init.h>
#include <linux/stringify.h>
-#include <linux/binfmts.h>
-#include <linux/futex.h>
#include <linux/lguest.h>
#include <linux/lguest_launcher.h>
#include <linux/wait.h>
#include <linux/err.h>
#include <asm/semaphore.h>
-#include "irq_vectors.h"
-
-#define GUEST_PL 1
-struct lguest_regs
-{
- /* Manually saved part. */
- unsigned long ebx, ecx, edx;
- unsigned long esi, edi, ebp;
- unsigned long gs;
- unsigned long eax;
- unsigned long fs, ds, es;
- unsigned long trapnum, errcode;
- /* Trap pushed part */
- unsigned long eip;
- unsigned long cs;
- unsigned long eflags;
- unsigned long esp;
- unsigned long ss;
-};
+#include <asm/lguest.h>
void free_pagetables(void);
int init_pagetables(struct page **switcher_page, unsigned int pages);
-/* Full 4G segment descriptors, suitable for CS and DS. */
-#define FULL_EXEC_SEGMENT ((struct desc_struct){0x0000ffff, 0x00cf9b00})
-#define FULL_SEGMENT ((struct desc_struct){0x0000ffff, 0x00cf9300})
-
-struct lguest_dma_info
-{
- struct list_head list;
- union futex_key key;
- unsigned long dmas;
- u16 next_dma;
- u16 num_dmas;
- u16 guestid;
- u8 interrupt; /* 0 when not registered */
-};
-
-/*H:310 The page-table code owes a great debt of gratitude to Andi Kleen. He
- * reviewed the original code which used "u32" for all page table entries, and
- * insisted that it would be far clearer with explicit typing. I thought it
- * was overkill, but he was right: it is much clearer than it was before.
- *
- * We have separate types for the Guest's ptes & pgds and the shadow ptes &
- * pgds. There's already a Linux type for these (pte_t and pgd_t) but they
- * change depending on kernel config options (PAE). */
-
-/* Each entry is identical: lower 12 bits of flags and upper 20 bits for the
- * "page frame number" (0 == first physical page, etc). They are different
- * types so the compiler will warn us if we mix them improperly. */
-typedef union {
- struct { unsigned flags:12, pfn:20; };
- struct { unsigned long val; } raw;
-} spgd_t;
-typedef union {
- struct { unsigned flags:12, pfn:20; };
- struct { unsigned long val; } raw;
-} spte_t;
-typedef union {
- struct { unsigned flags:12, pfn:20; };
- struct { unsigned long val; } raw;
-} gpgd_t;
-typedef union {
- struct { unsigned flags:12, pfn:20; };
- struct { unsigned long val; } raw;
-} gpte_t;
-
-/* We have two convenient macros to convert a "raw" value as handed to us by
- * the Guest into the correct Guest PGD or PTE type. */
-#define mkgpte(_val) ((gpte_t){.raw.val = _val})
-#define mkgpgd(_val) ((gpgd_t){.raw.val = _val})
-/*:*/
-
struct pgdir
{
- unsigned long cr3;
- spgd_t *pgdir;
-};
-
-/* This is a guest-specific page (mapped ro) into the guest. */
-struct lguest_ro_state
-{
- /* Host information we need to restore when we switch back. */
- u32 host_cr3;
- struct Xgt_desc_struct host_idt_desc;
- struct Xgt_desc_struct host_gdt_desc;
- u32 host_sp;
-
- /* Fields which are used when guest is running. */
- struct Xgt_desc_struct guest_idt_desc;
- struct Xgt_desc_struct guest_gdt_desc;
- struct i386_hw_tss guest_tss;
- struct desc_struct guest_idt[IDT_ENTRIES];
- struct desc_struct guest_gdt[GDT_ENTRIES];
+ unsigned long gpgdir;
+ pgd_t *pgdir;
};
/* We have two pages shared with guests, per cpu. */
@@ -141,9 +47,11 @@ struct lguest
struct lguest_data __user *lguest_data;
struct task_struct *tsk;
struct mm_struct *mm; /* == tsk->mm, but that becomes NULL on exit */
- u16 guestid;
u32 pfn_limit;
- u32 page_offset;
+ /* This provides the offset to the base of guest-physical
+ * memory in the Launcher. */
+ void __user *mem_base;
+ unsigned long kernel_address;
u32 cr2;
int halted;
int ts;
@@ -151,6 +59,9 @@ struct lguest
u32 esp1;
u8 ss1;
+ /* If a hypercall was asked for, this points to the arguments. */
+ struct hcall_args *hcall;
+
/* Do we need to stop what we're doing and return to userspace? */
int break_out;
wait_queue_head_t break_wq;
@@ -167,24 +78,15 @@ struct lguest
struct task_struct *wake;
unsigned long noirq_start, noirq_end;
- int dma_is_pending;
- unsigned long pending_dma; /* struct lguest_dma */
- unsigned long pending_key; /* address they're sending to */
+ unsigned long pending_notify; /* pfn from LHCALL_NOTIFY */
unsigned int stack_pages;
u32 tsc_khz;
- struct lguest_dma_info dma[LGUEST_MAX_DMA];
-
/* Dead? */
const char *dead;
- /* The GDT entries copied into lguest_ro_state when running. */
- struct desc_struct gdt[GDT_ENTRIES];
-
- /* The IDT entries: some copied into lguest_ro_state when running. */
- struct desc_struct idt[FIRST_EXTERNAL_VECTOR+LGUEST_IRQS];
- struct desc_struct syscall_idt;
+ struct lguest_arch arch;
/* Virtual clock device */
struct hrtimer hrt;
@@ -193,19 +95,38 @@ struct lguest
DECLARE_BITMAP(irqs_pending, LGUEST_IRQS);
};
-extern struct lguest lguests[];
extern struct mutex lguest_lock;
/* core.c: */
-u32 lgread_u32(struct lguest *lg, unsigned long addr);
-void lgwrite_u32(struct lguest *lg, unsigned long addr, u32 val);
-void lgread(struct lguest *lg, void *buf, unsigned long addr, unsigned len);
-void lgwrite(struct lguest *lg, unsigned long, const void *buf, unsigned len);
-int find_free_guest(void);
int lguest_address_ok(const struct lguest *lg,
unsigned long addr, unsigned long len);
+void __lgread(struct lguest *, void *, unsigned long, unsigned);
+void __lgwrite(struct lguest *, unsigned long, const void *, unsigned);
+
+/*L:306 Using memory-copy operations like that is usually inconvient, so we
+ * have the following helper macros which read and write a specific type (often
+ * an unsigned long).
+ *
+ * This reads into a variable of the given type then returns that. */
+#define lgread(lg, addr, type) \
+ ({ type _v; __lgread((lg), &_v, (addr), sizeof(_v)); _v; })
+
+/* This checks that the variable is of the given type, then writes it out. */
+#define lgwrite(lg, addr, type, val) \
+ do { \
+ typecheck(type, val); \
+ __lgwrite((lg), (addr), &(val), sizeof(val)); \
+ } while(0)
+/* (end of memory access helper routines) :*/
+
int run_guest(struct lguest *lg, unsigned long __user *user);
+/* Helper macros to obtain the first 12 or the last 20 bits, this is only the
+ * first step in the migration to the kernel types. pte_pfn is already defined
+ * in the kernel. */
+#define pgd_flags(x) (pgd_val(x) & ~PAGE_MASK)
+#define pte_flags(x) (pte_val(x) & ~PAGE_MASK)
+#define pgd_pfn(x) (pgd_val(x) >> PAGE_SHIFT)
/* interrupts_and_traps.c: */
void maybe_do_interrupt(struct lguest *lg);
@@ -219,6 +140,9 @@ void copy_traps(const struct lguest *lg, struct desc_struct *idt,
const unsigned long *def);
void guest_set_clockevent(struct lguest *lg, unsigned long delta);
void init_clockdev(struct lguest *lg);
+bool check_syscall_vector(struct lguest *lg);
+int init_interrupts(void);
+void free_interrupts(void);
/* segments.c: */
void setup_default_gdt_entries(struct lguest_ro_state *state);
@@ -232,28 +156,33 @@ void copy_gdt_tls(const struct lguest *lg, struct desc_struct *gdt);
int init_guest_pagetable(struct lguest *lg, unsigned long pgtable);
void free_guest_pagetable(struct lguest *lg);
void guest_new_pagetable(struct lguest *lg, unsigned long pgtable);
-void guest_set_pmd(struct lguest *lg, unsigned long cr3, u32 i);
+void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 i);
void guest_pagetable_clear_all(struct lguest *lg);
void guest_pagetable_flush_user(struct lguest *lg);
-void guest_set_pte(struct lguest *lg, unsigned long cr3,
- unsigned long vaddr, gpte_t val);
+void guest_set_pte(struct lguest *lg, unsigned long gpgdir,
+ unsigned long vaddr, pte_t val);
void map_switcher_in_guest(struct lguest *lg, struct lguest_pages *pages);
int demand_page(struct lguest *info, unsigned long cr2, int errcode);
void pin_page(struct lguest *lg, unsigned long vaddr);
+unsigned long guest_pa(struct lguest *lg, unsigned long vaddr);
+void page_table_guest_data_init(struct lguest *lg);
+
+/* <arch>/core.c: */
+void lguest_arch_host_init(void);
+void lguest_arch_host_fini(void);
+void lguest_arch_run_guest(struct lguest *lg);
+void lguest_arch_handle_trap(struct lguest *lg);
+int lguest_arch_init_hypercalls(struct lguest *lg);
+int lguest_arch_do_hcall(struct lguest *lg, struct hcall_args *args);
+void lguest_arch_setup_regs(struct lguest *lg, unsigned long start);
+
+/* <arch>/switcher.S: */
+extern char start_switcher_text[], end_switcher_text[], switch_to_guest[];
/* lguest_user.c: */
int lguest_device_init(void);
void lguest_device_remove(void);
-/* io.c: */
-void lguest_io_init(void);
-int bind_dma(struct lguest *lg,
- unsigned long key, unsigned long udma, u16 numdmas, u8 interrupt);
-void send_dma(struct lguest *info, unsigned long key, unsigned long udma);
-void release_all_dma(struct lguest *lg);
-unsigned long get_dma_buffer(struct lguest *lg, unsigned long key,
- unsigned long *interrupt);
-
/* hypercalls.c: */
void do_hypercalls(struct lguest *lg);
void write_timestamp(struct lguest *lg);
@@ -292,9 +221,5 @@ do { \
} while(0)
/* (End of aside) :*/
-static inline unsigned long guest_pa(struct lguest *lg, unsigned long vaddr)
-{
- return vaddr - lg->page_offset;
-}
#endif /* __ASSEMBLY__ */
#endif /* _LGUEST_H */
diff --git a/drivers/lguest/lguest.c b/drivers/lguest/lguest.c
deleted file mode 100644
index 3ba337dde85..00000000000
--- a/drivers/lguest/lguest.c
+++ /dev/null
@@ -1,1108 +0,0 @@
-/*P:010
- * A hypervisor allows multiple Operating Systems to run on a single machine.
- * To quote David Wheeler: "Any problem in computer science can be solved with
- * another layer of indirection."
- *
- * We keep things simple in two ways. First, we start with a normal Linux
- * kernel and insert a module (lg.ko) which allows us to run other Linux
- * kernels the same way we'd run processes. We call the first kernel the Host,
- * and the others the Guests. The program which sets up and configures Guests
- * (such as the example in Documentation/lguest/lguest.c) is called the
- * Launcher.
- *
- * Secondly, we only run specially modified Guests, not normal kernels. When
- * you set CONFIG_LGUEST to 'y' or 'm', this automatically sets
- * CONFIG_LGUEST_GUEST=y, which compiles this file into the kernel so it knows
- * how to be a Guest. This means that you can use the same kernel you boot
- * normally (ie. as a Host) as a Guest.
- *
- * These Guests know that they cannot do privileged operations, such as disable
- * interrupts, and that they have to ask the Host to do such things explicitly.
- * This file consists of all the replacements for such low-level native
- * hardware operations: these special Guest versions call the Host.
- *
- * So how does the kernel know it's a Guest? The Guest starts at a special
- * entry point marked with a magic string, which sets up a few things then
- * calls here. We replace the native functions various "paravirt" structures
- * with our Guest versions, then boot like normal. :*/
-
-/*
- * Copyright (C) 2006, Rusty Russell <rusty@rustcorp.com.au> IBM Corporation.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
- * NON INFRINGEMENT. See the GNU General Public License for more
- * details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-#include <linux/kernel.h>
-#include <linux/start_kernel.h>
-#include <linux/string.h>
-#include <linux/console.h>
-#include <linux/screen_info.h>
-#include <linux/irq.h>
-#include <linux/interrupt.h>
-#include <linux/clocksource.h>
-#include <linux/clockchips.h>
-#include <linux/lguest.h>
-#include <linux/lguest_launcher.h>
-#include <linux/lguest_bus.h>
-#include <asm/paravirt.h>
-#include <asm/param.h>
-#include <asm/page.h>
-#include <asm/pgtable.h>
-#include <asm/desc.h>
-#include <asm/setup.h>
-#include <asm/e820.h>
-#include <asm/mce.h>
-#include <asm/io.h>
-
-/*G:010 Welcome to the Guest!
- *
- * The Guest in our tale is a simple creature: identical to the Host but
- * behaving in simplified but equivalent ways. In particular, the Guest is the
- * same kernel as the Host (or at least, built from the same source code). :*/
-
-/* Declarations for definitions in lguest_guest.S */
-extern char lguest_noirq_start[], lguest_noirq_end[];
-extern const char lgstart_cli[], lgend_cli[];
-extern const char lgstart_sti[], lgend_sti[];
-extern const char lgstart_popf[], lgend_popf[];
-extern const char lgstart_pushf[], lgend_pushf[];
-extern const char lgstart_iret[], lgend_iret[];
-extern void lguest_iret(void);
-
-struct lguest_data lguest_data = {
- .hcall_status = { [0 ... LHCALL_RING_SIZE-1] = 0xFF },
- .noirq_start = (u32)lguest_noirq_start,
- .noirq_end = (u32)lguest_noirq_end,
- .blocked_interrupts = { 1 }, /* Block timer interrupts */
-};
-struct lguest_device_desc *lguest_devices;
-static cycle_t clock_base;
-
-/*G:035 Notice the lazy_hcall() above, rather than hcall(). This is our first
- * real optimization trick!
- *
- * When lazy_mode is set, it means we're allowed to defer all hypercalls and do
- * them as a batch when lazy_mode is eventually turned off. Because hypercalls
- * are reasonably expensive, batching them up makes sense. For example, a
- * large mmap might update dozens of page table entries: that code calls
- * paravirt_enter_lazy_mmu(), does the dozen updates, then calls
- * lguest_leave_lazy_mode().
- *
- * So, when we're in lazy mode, we call async_hypercall() to store the call for
- * future processing. When lazy mode is turned off we issue a hypercall to
- * flush the stored calls.
- */
-static void lguest_leave_lazy_mode(void)
-{
- paravirt_leave_lazy(paravirt_get_lazy_mode());
- hcall(LHCALL_FLUSH_ASYNC, 0, 0, 0);
-}
-
-static void lazy_hcall(unsigned long call,
- unsigned long arg1,
- unsigned long arg2,
- unsigned long arg3)
-{
- if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE)
- hcall(call, arg1, arg2, arg3);
- else
- async_hcall(call, arg1, arg2, arg3);
-}
-
-/* async_hcall() is pretty simple: I'm quite proud of it really. We have a
- * ring buffer of stored hypercalls which the Host will run though next time we
- * do a normal hypercall. Each entry in the ring has 4 slots for the hypercall
- * arguments, and a "hcall_status" word which is 0 if the call is ready to go,
- * and 255 once the Host has finished with it.
- *
- * If we come around to a slot which hasn't been finished, then the table is
- * full and we just make the hypercall directly. This has the nice side
- * effect of causing the Host to run all the stored calls in the ring buffer
- * which empties it for next time! */
-void async_hcall(unsigned long call,
- unsigned long arg1, unsigned long arg2, unsigned long arg3)
-{
- /* Note: This code assumes we're uniprocessor. */
- static unsigned int next_call;
- unsigned long flags;
-
- /* Disable interrupts if not already disabled: we don't want an
- * interrupt handler making a hypercall while we're already doing
- * one! */
- local_irq_save(flags);
- if (lguest_data.hcall_status[next_call] != 0xFF) {
- /* Table full, so do normal hcall which will flush table. */
- hcall(call, arg1, arg2, arg3);
- } else {
- lguest_data.hcalls[next_call].eax = call;
- lguest_data.hcalls[next_call].edx = arg1;
- lguest_data.hcalls[next_call].ebx = arg2;
- lguest_data.hcalls[next_call].ecx = arg3;
- /* Arguments must all be written before we mark it to go */
- wmb();
- lguest_data.hcall_status[next_call] = 0;
- if (++next_call == LHCALL_RING_SIZE)
- next_call = 0;
- }
- local_irq_restore(flags);
-}
-/*:*/
-
-/* Wrappers for the SEND_DMA and BIND_DMA hypercalls. This is mainly because
- * Jeff Garzik complained that __pa() should never appear in drivers, and this
- * helps remove most of them. But also, it wraps some ugliness. */
-void lguest_send_dma(unsigned long key, struct lguest_dma *dma)
-{
- /* The hcall might not write this if something goes wrong */
- dma->used_len = 0;
- hcall(LHCALL_SEND_DMA, key, __pa(dma), 0);
-}
-
-int lguest_bind_dma(unsigned long key, struct lguest_dma *dmas,
- unsigned int num, u8 irq)
-{
- /* This is the only hypercall which actually wants 5 arguments, and we
- * only support 4. Fortunately the interrupt number is always less
- * than 256, so we can pack it with the number of dmas in the final
- * argument. */
- if (!hcall(LHCALL_BIND_DMA, key, __pa(dmas), (num << 8) | irq))
- return -ENOMEM;
- return 0;
-}
-
-/* Unbinding is the same hypercall as binding, but with 0 num & irq. */
-void lguest_unbind_dma(unsigned long key, struct lguest_dma *dmas)
-{
- hcall(LHCALL_BIND_DMA, key, __pa(dmas), 0);
-}
-
-/* For guests, device memory can be used as normal memory, so we cast away the
- * __iomem to quieten sparse. */
-void *lguest_map(unsigned long phys_addr, unsigned long pages)
-{
- return (__force void *)ioremap(phys_addr, PAGE_SIZE*pages);
-}
-
-void lguest_unmap(void *addr)
-{
- iounmap((__force void __iomem *)addr);
-}
-
-/*G:033
- * Here are our first native-instruction replacements: four functions for
- * interrupt control.
- *
- * The simplest way of implementing these would be to have "turn interrupts
- * off" and "turn interrupts on" hypercalls. Unfortunately, this is too slow:
- * these are by far the most commonly called functions of those we override.
- *
- * So instead we keep an "irq_enabled" field inside our "struct lguest_data",
- * which the Guest can update with a single instruction. The Host knows to
- * check there when it wants to deliver an interrupt.
- */
-
-/* save_flags() is expected to return the processor state (ie. "eflags"). The
- * eflags word contains all kind of stuff, but in practice Linux only cares
- * about the interrupt flag. Our "save_flags()" just returns that. */
-static unsigned long save_fl(void)
-{
- return lguest_data.irq_enabled;
-}
-
-/* "restore_flags" just sets the flags back to the value given. */
-static void restore_fl(unsigned long flags)
-{
- lguest_data.irq_enabled = flags;
-}
-
-/* Interrupts go off... */
-static void irq_disable(void)
-{
- lguest_data.irq_enabled = 0;
-}
-
-/* Interrupts go on... */
-static void irq_enable(void)
-{
- lguest_data.irq_enabled = X86_EFLAGS_IF;
-}
-/*:*/
-/*M:003 Note that we don't check for outstanding interrupts when we re-enable
- * them (or when we unmask an interrupt). This seems to work for the moment,
- * since interrupts are rare and we'll just get the interrupt on the next timer
- * tick, but when we turn on CONFIG_NO_HZ, we should revisit this. One way
- * would be to put the "irq_enabled" field in a page by itself, and have the
- * Host write-protect it when an interrupt comes in when irqs are disabled.
- * There will then be a page fault as soon as interrupts are re-enabled. :*/
-
-/*G:034
- * The Interrupt Descriptor Table (IDT).
- *
- * The IDT tells the processor what to do when an interrupt comes in. Each
- * entry in the table is a 64-bit descriptor: this holds the privilege level,
- * address of the handler, and... well, who cares? The Guest just asks the
- * Host to make the change anyway, because the Host controls the real IDT.
- */
-static void lguest_write_idt_entry(struct desc_struct *dt,
- int entrynum, u32 low, u32 high)
-{
- /* Keep the local copy up to date. */
- write_dt_entry(dt, entrynum, low, high);
- /* Tell Host about this new entry. */
- hcall(LHCALL_LOAD_IDT_ENTRY, entrynum, low, high);
-}
-
-/* Changing to a different IDT is very rare: we keep the IDT up-to-date every
- * time it is written, so we can simply loop through all entries and tell the
- * Host about them. */
-static void lguest_load_idt(const struct Xgt_desc_struct *desc)
-{
- unsigned int i;
- struct desc_struct *idt = (void *)desc->address;
-
- for (i = 0; i < (desc->size+1)/8; i++)
- hcall(LHCALL_LOAD_IDT_ENTRY, i, idt[i].a, idt[i].b);
-}
-
-/*
- * The Global Descriptor Table.
- *
- * The Intel architecture defines another table, called the Global Descriptor
- * Table (GDT). You tell the CPU where it is (and its size) using the "lgdt"
- * instruction, and then several other instructions refer to entries in the
- * table. There are three entries which the Switcher needs, so the Host simply
- * controls the entire thing and the Guest asks it to make changes using the
- * LOAD_GDT hypercall.
- *
- * This is the opposite of the IDT code where we have a LOAD_IDT_ENTRY
- * hypercall and use that repeatedly to load a new IDT. I don't think it
- * really matters, but wouldn't it be nice if they were the same?
- */
-static void lguest_load_gdt(const struct Xgt_desc_struct *desc)
-{
- BUG_ON((desc->size+1)/8 != GDT_ENTRIES);
- hcall(LHCALL_LOAD_GDT, __pa(desc->address), GDT_ENTRIES, 0);
-}
-
-/* For a single GDT entry which changes, we do the lazy thing: alter our GDT,
- * then tell the Host to reload the entire thing. This operation is so rare
- * that this naive implementation is reasonable. */
-static void lguest_write_gdt_entry(struct desc_struct *dt,
- int entrynum, u32 low, u32 high)
-{
- write_dt_entry(dt, entrynum, low, high);
- hcall(LHCALL_LOAD_GDT, __pa(dt), GDT_ENTRIES, 0);
-}
-
-/* OK, I lied. There are three "thread local storage" GDT entries which change
- * on every context switch (these three entries are how glibc implements
- * __thread variables). So we have a hypercall specifically for this case. */
-static void lguest_load_tls(struct thread_struct *t, unsigned int cpu)
-{
- /* There's one problem which normal hardware doesn't have: the Host
- * can't handle us removing entries we're currently using. So we clear
- * the GS register here: if it's needed it'll be reloaded anyway. */
- loadsegment(gs, 0);
- lazy_hcall(LHCALL_LOAD_TLS, __pa(&t->tls_array), cpu, 0);
-}
-
-/*G:038 That's enough excitement for now, back to ploughing through each of
- * the different pv_ops structures (we're about 1/3 of the way through).
- *
- * This is the Local Descriptor Table, another weird Intel thingy. Linux only
- * uses this for some strange applications like Wine. We don't do anything
- * here, so they'll get an informative and friendly Segmentation Fault. */
-static void lguest_set_ldt(const void *addr, unsigned entries)
-{
-}
-
-/* This loads a GDT entry into the "Task Register": that entry points to a
- * structure called the Task State Segment. Some comments scattered though the
- * kernel code indicate that this used for task switching in ages past, along
- * with blood sacrifice and astrology.
- *
- * Now there's nothing interesting in here that we don't get told elsewhere.
- * But the native version uses the "ltr" instruction, which makes the Host
- * complain to the Guest about a Segmentation Fault and it'll oops. So we
- * override the native version with a do-nothing version. */
-static void lguest_load_tr_desc(void)
-{
-}
-
-/* The "cpuid" instruction is a way of querying both the CPU identity
- * (manufacturer, model, etc) and its features. It was introduced before the
- * Pentium in 1993 and keeps getting extended by both Intel and AMD. As you
- * might imagine, after a decade and a half this treatment, it is now a giant
- * ball of hair. Its entry in the current Intel manual runs to 28 pages.
- *
- * This instruction even it has its own Wikipedia entry. The Wikipedia entry
- * has been translated into 4 languages. I am not making this up!
- *
- * We could get funky here and identify ourselves as "GenuineLguest", but
- * instead we just use the real "cpuid" instruction. Then I pretty much turned
- * off feature bits until the Guest booted. (Don't say that: you'll damage
- * lguest sales!) Shut up, inner voice! (Hey, just pointing out that this is
- * hardly future proof.) Noone's listening! They don't like you anyway,
- * parenthetic weirdo!
- *
- * Replacing the cpuid so we can turn features off is great for the kernel, but
- * anyone (including userspace) can just use the raw "cpuid" instruction and
- * the Host won't even notice since it isn't privileged. So we try not to get
- * too worked up about it. */
-static void lguest_cpuid(unsigned int *eax, unsigned int *ebx,
- unsigned int *ecx, unsigned int *edx)
-{
- int function = *eax;
-
- native_cpuid(eax, ebx, ecx, edx);
- switch (function) {
- case 1: /* Basic feature request. */
- /* We only allow kernel to see SSE3, CMPXCHG16B and SSSE3 */
- *ecx &= 0x00002201;
- /* SSE, SSE2, FXSR, MMX, CMOV, CMPXCHG8B, FPU. */
- *edx &= 0x07808101;
- /* The Host can do a nice optimization if it knows that the
- * kernel mappings (addresses above 0xC0000000 or whatever
- * PAGE_OFFSET is set to) haven't changed. But Linux calls
- * flush_tlb_user() for both user and kernel mappings unless
- * the Page Global Enable (PGE) feature bit is set. */
- *edx |= 0x00002000;
- break;
- case 0x80000000:
- /* Futureproof this a little: if they ask how much extended
- * processor information there is, limit it to known fields. */
- if (*eax > 0x80000008)
- *eax = 0x80000008;
- break;
- }
-}
-
-/* Intel has four control registers, imaginatively named cr0, cr2, cr3 and cr4.
- * I assume there's a cr1, but it hasn't bothered us yet, so we'll not bother
- * it. The Host needs to know when the Guest wants to change them, so we have
- * a whole series of functions like read_cr0() and write_cr0().
- *
- * We start with CR0. CR0 allows you to turn on and off all kinds of basic
- * features, but Linux only really cares about one: the horrifically-named Task
- * Switched (TS) bit at bit 3 (ie. 8)
- *
- * What does the TS bit do? Well, it causes the CPU to trap (interrupt 7) if
- * the floating point unit is used. Which allows us to restore FPU state
- * lazily after a task switch, and Linux uses that gratefully, but wouldn't a
- * name like "FPUTRAP bit" be a little less cryptic?
- *
- * We store cr0 (and cr3) locally, because the Host never changes it. The
- * Guest sometimes wants to read it and we'd prefer not to bother the Host
- * unnecessarily. */
-static unsigned long current_cr0, current_cr3;
-static void lguest_write_cr0(unsigned long val)
-{
- /* 8 == TS bit. */
- lazy_hcall(LHCALL_TS, val & 8, 0, 0);
- current_cr0 = val;
-}
-
-static unsigned long lguest_read_cr0(void)
-{
- return current_cr0;
-}
-
-/* Intel provided a special instruction to clear the TS bit for people too cool
- * to use write_cr0() to do it. This "clts" instruction is faster, because all
- * the vowels have been optimized out. */
-static void lguest_clts(void)
-{
- lazy_hcall(LHCALL_TS, 0, 0, 0);
- current_cr0 &= ~8U;
-}
-
-/* CR2 is the virtual address of the last page fault, which the Guest only ever
- * reads. The Host kindly writes this into our "struct lguest_data", so we
- * just read it out of there. */
-static unsigned long lguest_read_cr2(void)
-{
- return lguest_data.cr2;
-}
-
-/* CR3 is the current toplevel pagetable page: the principle is the same as
- * cr0. Keep a local copy, and tell the Host when it changes. */
-static void lguest_write_cr3(unsigned long cr3)
-{
- lazy_hcall(LHCALL_NEW_PGTABLE, cr3, 0, 0);
- current_cr3 = cr3;
-}
-
-static unsigned long lguest_read_cr3(void)
-{
- return current_cr3;
-}
-
-/* CR4 is used to enable and disable PGE, but we don't care. */
-static unsigned long lguest_read_cr4(void)
-{
- return 0;
-}
-
-static void lguest_write_cr4(unsigned long val)
-{
-}
-
-/*
- * Page Table Handling.
- *
- * Now would be a good time to take a rest and grab a coffee or similarly
- * relaxing stimulant. The easy parts are behind us, and the trek gradually
- * winds uphill from here.
- *
- * Quick refresher: memory is divided into "pages" of 4096 bytes each. The CPU
- * maps virtual addresses to physical addresses using "page tables". We could
- * use one huge index of 1 million entries: each address is 4 bytes, so that's
- * 1024 pages just to hold the page tables. But since most virtual addresses
- * are unused, we use a two level index which saves space. The CR3 register
- * contains the physical address of the top level "page directory" page, which
- * contains physical addresses of up to 1024 second-level pages. Each of these
- * second level pages contains up to 1024 physical addresses of actual pages,
- * or Page Table Entries (PTEs).
- *
- * Here's a diagram, where arrows indicate physical addresses:
- *
- * CR3 ---> +---------+
- * | --------->+---------+
- * | | | PADDR1 |
- * Top-level | | PADDR2 |
- * (PMD) page | | |
- * | | Lower-level |
- * | | (PTE) page |
- * | | | |
- * .... ....
- *
- * So to convert a virtual address to a physical address, we look up the top
- * level, which points us to the second level, which gives us the physical
- * address of that page. If the top level entry was not present, or the second
- * level entry was not present, then the virtual address is invalid (we
- * say "the page was not mapped").
- *
- * Put another way, a 32-bit virtual address is divided up like so:
- *
- * 1 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
- * |<---- 10 bits ---->|<---- 10 bits ---->|<------ 12 bits ------>|
- * Index into top Index into second Offset within page
- * page directory page pagetable page
- *
- * The kernel spends a lot of time changing both the top-level page directory
- * and lower-level pagetable pages. The Guest doesn't know physical addresses,
- * so while it maintains these page tables exactly like normal, it also needs
- * to keep the Host informed whenever it makes a change: the Host will create
- * the real page tables based on the Guests'.
- */
-
-/* The Guest calls this to set a second-level entry (pte), ie. to map a page
- * into a process' address space. We set the entry then tell the Host the
- * toplevel and address this corresponds to. The Guest uses one pagetable per
- * process, so we need to tell the Host which one we're changing (mm->pgd). */
-static void lguest_set_pte_at(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pteval)
-{
- *ptep = pteval;
- lazy_hcall(LHCALL_SET_PTE, __pa(mm->pgd), addr, pteval.pte_low);
-}
-
-/* The Guest calls this to set a top-level entry. Again, we set the entry then
- * tell the Host which top-level page we changed, and the index of the entry we
- * changed. */
-static void lguest_set_pmd(pmd_t *pmdp, pmd_t pmdval)
-{
- *pmdp = pmdval;
- lazy_hcall(LHCALL_SET_PMD, __pa(pmdp)&PAGE_MASK,
- (__pa(pmdp)&(PAGE_SIZE-1))/4, 0);
-}
-
-/* There are a couple of legacy places where the kernel sets a PTE, but we
- * don't know the top level any more. This is useless for us, since we don't
- * know which pagetable is changing or what address, so we just tell the Host
- * to forget all of them. Fortunately, this is very rare.
- *
- * ... except in early boot when the kernel sets up the initial pagetables,
- * which makes booting astonishingly slow. So we don't even tell the Host
- * anything changed until we've done the first page table switch.
- */
-static void lguest_set_pte(pte_t *ptep, pte_t pteval)
-{
- *ptep = pteval;
- /* Don't bother with hypercall before initial setup. */
- if (current_cr3)
- lazy_hcall(LHCALL_FLUSH_TLB, 1, 0, 0);
-}
-
-/* Unfortunately for Lguest, the pv_mmu_ops for page tables were based on
- * native page table operations. On native hardware you can set a new page
- * table entry whenever you want, but if you want to remove one you have to do
- * a TLB flush (a TLB is a little cache of page table entries kept by the CPU).
- *
- * So the lguest_set_pte_at() and lguest_set_pmd() functions above are only
- * called when a valid entry is written, not when it's removed (ie. marked not
- * present). Instead, this is where we come when the Guest wants to remove a
- * page table entry: we tell the Host to set that entry to 0 (ie. the present
- * bit is zero). */
-static void lguest_flush_tlb_single(unsigned long addr)
-{
- /* Simply set it to zero: if it was not, it will fault back in. */
- lazy_hcall(LHCALL_SET_PTE, current_cr3, addr, 0);
-}
-
-/* This is what happens after the Guest has removed a large number of entries.
- * This tells the Host that any of the page table entries for userspace might
- * have changed, ie. virtual addresses below PAGE_OFFSET. */
-static void lguest_flush_tlb_user(void)
-{
- lazy_hcall(LHCALL_FLUSH_TLB, 0, 0, 0);
-}
-
-/* This is called when the kernel page tables have changed. That's not very
- * common (unless the Guest is using highmem, which makes the Guest extremely
- * slow), so it's worth separating this from the user flushing above. */
-static void lguest_flush_tlb_kernel(void)
-{
- lazy_hcall(LHCALL_FLUSH_TLB, 1, 0, 0);
-}
-
-/*
- * The Unadvanced Programmable Interrupt Controller.
- *
- * This is an attempt to implement the simplest possible interrupt controller.
- * I spent some time looking though routines like set_irq_chip_and_handler,
- * set_irq_chip_and_handler_name, set_irq_chip_data and set_phasers_to_stun and
- * I *think* this is as simple as it gets.
- *
- * We can tell the Host what interrupts we want blocked ready for using the
- * lguest_data.interrupts bitmap, so disabling (aka "masking") them is as
- * simple as setting a bit. We don't actually "ack" interrupts as such, we
- * just mask and unmask them. I wonder if we should be cleverer?
- */
-static void disable_lguest_irq(unsigned int irq)
-{
- set_bit(irq, lguest_data.blocked_interrupts);
-}
-
-static void enable_lguest_irq(unsigned int irq)
-{
- clear_bit(irq, lguest_data.blocked_interrupts);
-}
-
-/* This structure describes the lguest IRQ controller. */
-static struct irq_chip lguest_irq_controller = {
- .name = "lguest",
- .mask = disable_lguest_irq,
- .mask_ack = disable_lguest_irq,
- .unmask = enable_lguest_irq,
-};
-
-/* This sets up the Interrupt Descriptor Table (IDT) entry for each hardware
- * interrupt (except 128, which is used for system calls), and then tells the
- * Linux infrastructure that each interrupt is controlled by our level-based
- * lguest interrupt controller. */
-static void __init lguest_init_IRQ(void)
-{
- unsigned int i;
-
- for (i = 0; i < LGUEST_IRQS; i++) {
- int vector = FIRST_EXTERNAL_VECTOR + i;
- if (vector != SYSCALL_VECTOR) {
- set_intr_gate(vector, interrupt[i]);
- set_irq_chip_and_handler(i, &lguest_irq_controller,
- handle_level_irq);
- }
- }
- /* This call is required to set up for 4k stacks, where we have
- * separate stacks for hard and soft interrupts. */
- irq_ctx_init(smp_processor_id());
-}
-
-/*
- * Time.
- *
- * It would be far better for everyone if the Guest had its own clock, but
- * until then the Host gives us the time on every interrupt.
- */
-static unsigned long lguest_get_wallclock(void)
-{
- return lguest_data.time.tv_sec;
-}
-
-static cycle_t lguest_clock_read(void)
-{
- unsigned long sec, nsec;
-
- /* If the Host tells the TSC speed, we can trust that. */
- if (lguest_data.tsc_khz)
- return native_read_tsc();
-
- /* If we can't use the TSC, we read the time value written by the Host.
- * Since it's in two parts (seconds and nanoseconds), we risk reading
- * it just as it's changing from 99 & 0.999999999 to 100 and 0, and
- * getting 99 and 0. As Linux tends to come apart under the stress of
- * time travel, we must be careful: */
- do {
- /* First we read the seconds part. */
- sec = lguest_data.time.tv_sec;
- /* This read memory barrier tells the compiler and the CPU that
- * this can't be reordered: we have to complete the above
- * before going on. */
- rmb();
- /* Now we read the nanoseconds part. */
- nsec = lguest_data.time.tv_nsec;
- /* Make sure we've done that. */
- rmb();
- /* Now if the seconds part has changed, try again. */
- } while (unlikely(lguest_data.time.tv_sec != sec));
-
- /* Our non-TSC clock is in real nanoseconds. */
- return sec*1000000000ULL + nsec;
-}
-
-/* This is what we tell the kernel is our clocksource. */
-static struct clocksource lguest_clock = {
- .name = "lguest",
- .rating = 400,
- .read = lguest_clock_read,
- .mask = CLOCKSOURCE_MASK(64),
- .mult = 1 << 22,
- .shift = 22,
-};
-
-/* The "scheduler clock" is just our real clock, adjusted to start at zero */
-static unsigned long long lguest_sched_clock(void)
-{
- return cyc2ns(&lguest_clock, lguest_clock_read() - clock_base);
-}
-
-/* We also need a "struct clock_event_device": Linux asks us to set it to go
- * off some time in the future. Actually, James Morris figured all this out, I
- * just applied the patch. */
-static int lguest_clockevent_set_next_event(unsigned long delta,
- struct clock_event_device *evt)
-{
- if (delta < LG_CLOCK_MIN_DELTA) {
- if (printk_ratelimit())
- printk(KERN_DEBUG "%s: small delta %lu ns\n",
- __FUNCTION__, delta);
- return -ETIME;
- }
- hcall(LHCALL_SET_CLOCKEVENT, delta, 0, 0);
- return 0;
-}
-
-static void lguest_clockevent_set_mode(enum clock_event_mode mode,
- struct clock_event_device *evt)
-{
- switch (mode) {
- case CLOCK_EVT_MODE_UNUSED:
- case CLOCK_EVT_MODE_SHUTDOWN:
- /* A 0 argument shuts the clock down. */
- hcall(LHCALL_SET_CLOCKEVENT, 0, 0, 0);
- break;
- case CLOCK_EVT_MODE_ONESHOT:
- /* This is what we expect. */
- break;
- case CLOCK_EVT_MODE_PERIODIC:
- BUG();
- case CLOCK_EVT_MODE_RESUME:
- break;
- }
-}
-
-/* This describes our primitive timer chip. */
-static struct clock_event_device lguest_clockevent = {
- .name = "lguest",
- .features = CLOCK_EVT_FEAT_ONESHOT,
- .set_next_event = lguest_clockevent_set_next_event,
- .set_mode = lguest_clockevent_set_mode,
- .rating = INT_MAX,
- .mult = 1,
- .shift = 0,
- .min_delta_ns = LG_CLOCK_MIN_DELTA,
- .max_delta_ns = LG_CLOCK_MAX_DELTA,
-};
-
-/* This is the Guest timer interrupt handler (hardware interrupt 0). We just
- * call the clockevent infrastructure and it does whatever needs doing. */
-static void lguest_time_irq(unsigned int irq, struct irq_desc *desc)
-{
- unsigned long flags;
-
- /* Don't interrupt us while this is running. */
- local_irq_save(flags);
- lguest_clockevent.event_handler(&lguest_clockevent);
- local_irq_restore(flags);
-}
-
-/* At some point in the boot process, we get asked to set up our timing
- * infrastructure. The kernel doesn't expect timer interrupts before this, but
- * we cleverly initialized the "blocked_interrupts" field of "struct
- * lguest_data" so that timer interrupts were blocked until now. */
-static void lguest_time_init(void)
-{
- /* Set up the timer interrupt (0) to go to our simple timer routine */
- set_irq_handler(0, lguest_time_irq);
-
- /* Our clock structure look like arch/i386/kernel/tsc.c if we can use
- * the TSC, otherwise it's a dumb nanosecond-resolution clock. Either
- * way, the "rating" is initialized so high that it's always chosen
- * over any other clocksource. */
- if (lguest_data.tsc_khz) {
- lguest_clock.mult = clocksource_khz2mult(lguest_data.tsc_khz,
- lguest_clock.shift);
- lguest_clock.flags = CLOCK_SOURCE_IS_CONTINUOUS;
- }
- clock_base = lguest_clock_read();
- clocksource_register(&lguest_clock);
-
- /* Now we've set up our clock, we can use it as the scheduler clock */
- pv_time_ops.sched_clock = lguest_sched_clock;
-
- /* We can't set cpumask in the initializer: damn C limitations! Set it
- * here and register our timer device. */
- lguest_clockevent.cpumask = cpumask_of_cpu(0);
- clockevents_register_device(&lguest_clockevent);
-
- /* Finally, we unblock the timer interrupt. */
- enable_lguest_irq(0);
-}
-
-/*
- * Miscellaneous bits and pieces.
- *
- * Here is an oddball collection of functions which the Guest needs for things
- * to work. They're pretty simple.
- */
-
-/* The Guest needs to tell the host what stack it expects traps to use. For
- * native hardware, this is part of the Task State Segment mentioned above in
- * lguest_load_tr_desc(), but to help hypervisors there's this special call.
- *
- * We tell the Host the segment we want to use (__KERNEL_DS is the kernel data
- * segment), the privilege level (we're privilege level 1, the Host is 0 and
- * will not tolerate us trying to use that), the stack pointer, and the number
- * of pages in the stack. */
-static void lguest_load_esp0(struct tss_struct *tss,
- struct thread_struct *thread)
-{
- lazy_hcall(LHCALL_SET_STACK, __KERNEL_DS|0x1, thread->esp0,
- THREAD_SIZE/PAGE_SIZE);
-}
-
-/* Let's just say, I wouldn't do debugging under a Guest. */
-static void lguest_set_debugreg(int regno, unsigned long value)
-{
- /* FIXME: Implement */
-}
-
-/* There are times when the kernel wants to make sure that no memory writes are
- * caught in the cache (that they've all reached real hardware devices). This
- * doesn't matter for the Guest which has virtual hardware.
- *
- * On the Pentium 4 and above, cpuid() indicates that the Cache Line Flush
- * (clflush) instruction is available and the kernel uses that. Otherwise, it
- * uses the older "Write Back and Invalidate Cache" (wbinvd) instruction.
- * Unlike clflush, wbinvd can only be run at privilege level 0. So we can
- * ignore clflush, but replace wbinvd.
- */
-static void lguest_wbinvd(void)
-{
-}
-
-/* If the Guest expects to have an Advanced Programmable Interrupt Controller,
- * we play dumb by ignoring writes and returning 0 for reads. So it's no
- * longer Programmable nor Controlling anything, and I don't think 8 lines of
- * code qualifies for Advanced. It will also never interrupt anything. It
- * does, however, allow us to get through the Linux boot code. */
-#ifdef CONFIG_X86_LOCAL_APIC
-static void lguest_apic_write(unsigned long reg, unsigned long v)
-{
-}
-
-static unsigned long lguest_apic_read(unsigned long reg)
-{
- return 0;
-}
-#endif
-
-/* STOP! Until an interrupt comes in. */
-static void lguest_safe_halt(void)
-{
- hcall(LHCALL_HALT, 0, 0, 0);
-}
-
-/* Perhaps CRASH isn't the best name for this hypercall, but we use it to get a
- * message out when we're crashing as well as elegant termination like powering
- * off.
- *
- * Note that the Host always prefers that the Guest speak in physical addresses
- * rather than virtual addresses, so we use __pa() here. */
-static void lguest_power_off(void)
-{
- hcall(LHCALL_CRASH, __pa("Power down"), 0, 0);
-}
-
-/*
- * Panicing.
- *
- * Don't. But if you did, this is what happens.
- */
-static int lguest_panic(struct notifier_block *nb, unsigned long l, void *p)
-{
- hcall(LHCALL_CRASH, __pa(p), 0, 0);
- /* The hcall won't return, but to keep gcc happy, we're "done". */
- return NOTIFY_DONE;
-}
-
-static struct notifier_block paniced = {
- .notifier_call = lguest_panic
-};
-
-/* Setting up memory is fairly easy. */
-static __init char *lguest_memory_setup(void)
-{
- /* We do this here and not earlier because lockcheck barfs if we do it
- * before start_kernel() */
- atomic_notifier_chain_register(&panic_notifier_list, &paniced);
-
- /* The Linux bootloader header contains an "e820" memory map: the
- * Launcher populated the first entry with our memory limit. */
- add_memory_region(boot_params.e820_map[0].addr,
- boot_params.e820_map[0].size,
- boot_params.e820_map[0].type);
-
- /* This string is for the boot messages. */
- return "LGUEST";
-}
-
-/*G:050
- * Patching (Powerfully Placating Performance Pedants)
- *
- * We have already seen that pv_ops structures let us replace simple
- * native instructions with calls to the appropriate back end all throughout
- * the kernel. This allows the same kernel to run as a Guest and as a native
- * kernel, but it's slow because of all the indirect branches.
- *
- * Remember that David Wheeler quote about "Any problem in computer science can
- * be solved with another layer of indirection"? The rest of that quote is
- * "... But that usually will create another problem." This is the first of
- * those problems.
- *
- * Our current solution is to allow the paravirt back end to optionally patch
- * over the indirect calls to replace them with something more efficient. We
- * patch the four most commonly called functions: disable interrupts, enable
- * interrupts, restore interrupts and save interrupts. We usually have 10
- * bytes to patch into: the Guest versions of these operations are small enough
- * that we can fit comfortably.
- *
- * First we need assembly templates of each of the patchable Guest operations,
- * and these are in lguest_asm.S. */
-
-/*G:060 We construct a table from the assembler templates: */
-static const struct lguest_insns
-{
- const char *start, *end;
-} lguest_insns[] = {
- [PARAVIRT_PATCH(pv_irq_ops.irq_disable)] = { lgstart_cli, lgend_cli },
- [PARAVIRT_PATCH(pv_irq_ops.irq_enable)] = { lgstart_sti, lgend_sti },
- [PARAVIRT_PATCH(pv_irq_ops.restore_fl)] = { lgstart_popf, lgend_popf },
- [PARAVIRT_PATCH(pv_irq_ops.save_fl)] = { lgstart_pushf, lgend_pushf },
-};
-
-/* Now our patch routine is fairly simple (based on the native one in
- * paravirt.c). If we have a replacement, we copy it in and return how much of
- * the available space we used. */
-static unsigned lguest_patch(u8 type, u16 clobber, void *ibuf,
- unsigned long addr, unsigned len)
-{
- unsigned int insn_len;
-
- /* Don't do anything special if we don't have a replacement */
- if (type >= ARRAY_SIZE(lguest_insns) || !lguest_insns[type].start)
- return paravirt_patch_default(type, clobber, ibuf, addr, len);
-
- insn_len = lguest_insns[type].end - lguest_insns[type].start;
-
- /* Similarly if we can't fit replacement (shouldn't happen, but let's
- * be thorough). */
- if (len < insn_len)
- return paravirt_patch_default(type, clobber, ibuf, addr, len);
-
- /* Copy in our instructions. */
- memcpy(ibuf, lguest_insns[type].start, insn_len);
- return insn_len;
-}
-
-/*G:030 Once we get to lguest_init(), we know we're a Guest. The pv_ops
- * structures in the kernel provide points for (almost) every routine we have
- * to override to avoid privileged instructions. */
-__init void lguest_init(void *boot)
-{
- /* Copy boot parameters first: the Launcher put the physical location
- * in %esi, and head.S converted that to a virtual address and handed
- * it to us. We use "__memcpy" because "memcpy" sometimes tries to do
- * tricky things to go faster, and we're not ready for that. */
- __memcpy(&boot_params, boot, PARAM_SIZE);
- /* The boot parameters also tell us where the command-line is: save
- * that, too. */
- __memcpy(boot_command_line, __va(boot_params.hdr.cmd_line_ptr),
- COMMAND_LINE_SIZE);
-
- /* We're under lguest, paravirt is enabled, and we're running at
- * privilege level 1, not 0 as normal. */
- pv_info.name = "lguest";
- pv_info.paravirt_enabled = 1;
- pv_info.kernel_rpl = 1;
-
- /* We set up all the lguest overrides for sensitive operations. These
- * are detailed with the operations themselves. */
-
- /* interrupt-related operations */
- pv_irq_ops.init_IRQ = lguest_init_IRQ;
- pv_irq_ops.save_fl = save_fl;
- pv_irq_ops.restore_fl = restore_fl;
- pv_irq_ops.irq_disable = irq_disable;
- pv_irq_ops.irq_enable = irq_enable;
- pv_irq_ops.safe_halt = lguest_safe_halt;
-
- /* init-time operations */
- pv_init_ops.memory_setup = lguest_memory_setup;
- pv_init_ops.patch = lguest_patch;
-
- /* Intercepts of various cpu instructions */
- pv_cpu_ops.load_gdt = lguest_load_gdt;
- pv_cpu_ops.cpuid = lguest_cpuid;
- pv_cpu_ops.load_idt = lguest_load_idt;
- pv_cpu_ops.iret = lguest_iret;
- pv_cpu_ops.load_esp0 = lguest_load_esp0;
- pv_cpu_ops.load_tr_desc = lguest_load_tr_desc;
- pv_cpu_ops.set_ldt = lguest_set_ldt;
- pv_cpu_ops.load_tls = lguest_load_tls;
- pv_cpu_ops.set_debugreg = lguest_set_debugreg;
- pv_cpu_ops.clts = lguest_clts;
- pv_cpu_ops.read_cr0 = lguest_read_cr0;
- pv_cpu_ops.write_cr0 = lguest_write_cr0;
- pv_cpu_ops.read_cr4 = lguest_read_cr4;
- pv_cpu_ops.write_cr4 = lguest_write_cr4;
- pv_cpu_ops.write_gdt_entry = lguest_write_gdt_entry;
- pv_cpu_ops.write_idt_entry = lguest_write_idt_entry;
- pv_cpu_ops.wbinvd = lguest_wbinvd;
- pv_cpu_ops.lazy_mode.enter = paravirt_enter_lazy_cpu;
- pv_cpu_ops.lazy_mode.leave = lguest_leave_lazy_mode;
-
- /* pagetable management */
- pv_mmu_ops.write_cr3 = lguest_write_cr3;
- pv_mmu_ops.flush_tlb_user = lguest_flush_tlb_user;
- pv_mmu_ops.flush_tlb_single = lguest_flush_tlb_single;
- pv_mmu_ops.flush_tlb_kernel = lguest_flush_tlb_kernel;
- pv_mmu_ops.set_pte = lguest_set_pte;
- pv_mmu_ops.set_pte_at = lguest_set_pte_at;
- pv_mmu_ops.set_pmd = lguest_set_pmd;
- pv_mmu_ops.read_cr2 = lguest_read_cr2;
- pv_mmu_ops.read_cr3 = lguest_read_cr3;
- pv_mmu_ops.lazy_mode.enter = paravirt_enter_lazy_mmu;
- pv_mmu_ops.lazy_mode.leave = lguest_leave_lazy_mode;
-
-#ifdef CONFIG_X86_LOCAL_APIC
- /* apic read/write intercepts */
- pv_apic_ops.apic_write = lguest_apic_write;
- pv_apic_ops.apic_write_atomic = lguest_apic_write;
- pv_apic_ops.apic_read = lguest_apic_read;
-#endif
-
- /* time operations */
- pv_time_ops.get_wallclock = lguest_get_wallclock;
- pv_time_ops.time_init = lguest_time_init;
-
- /* Now is a good time to look at the implementations of these functions
- * before returning to the rest of lguest_init(). */
-
- /*G:070 Now we've seen all the paravirt_ops, we return to
- * lguest_init() where the rest of the fairly chaotic boot setup
- * occurs.
- *
- * The Host expects our first hypercall to tell it where our "struct
- * lguest_data" is, so we do that first. */
- hcall(LHCALL_LGUEST_INIT, __pa(&lguest_data), 0, 0);
-
- /* The native boot code sets up initial page tables immediately after
- * the kernel itself, and sets init_pg_tables_end so they're not
- * clobbered. The Launcher places our initial pagetables somewhere at
- * the top of our physical memory, so we don't need extra space: set
- * init_pg_tables_end to the end of the kernel. */
- init_pg_tables_end = __pa(pg0);
-
- /* Load the %fs segment register (the per-cpu segment register) with
- * the normal data segment to get through booting. */
- asm volatile ("mov %0, %%fs" : : "r" (__KERNEL_DS) : "memory");
-
- /* Clear the part of the kernel data which is expected to be zero.
- * Normally it will be anyway, but if we're loading from a bzImage with
- * CONFIG_RELOCATALE=y, the relocations will be sitting here. */
- memset(__bss_start, 0, __bss_stop - __bss_start);
-
- /* The Host uses the top of the Guest's virtual address space for the
- * Host<->Guest Switcher, and it tells us how much it needs in
- * lguest_data.reserve_mem, set up on the LGUEST_INIT hypercall. */
- reserve_top_address(lguest_data.reserve_mem);
-
- /* If we don't initialize the lock dependency checker now, it crashes
- * paravirt_disable_iospace. */
- lockdep_init();
-
- /* The IDE code spends about 3 seconds probing for disks: if we reserve
- * all the I/O ports up front it can't get them and so doesn't probe.
- * Other device drivers are similar (but less severe). This cuts the
- * kernel boot time on my machine from 4.1 seconds to 0.45 seconds. */
- paravirt_disable_iospace();
-
- /* This is messy CPU setup stuff which the native boot code does before
- * start_kernel, so we have to do, too: */
- cpu_detect(&new_cpu_data);
- /* head.S usually sets up the first capability word, so do it here. */
- new_cpu_data.x86_capability[0] = cpuid_edx(1);
-
- /* Math is always hard! */
- new_cpu_data.hard_math = 1;
-
-#ifdef CONFIG_X86_MCE
- mce_disabled = 1;
-#endif
-#ifdef CONFIG_ACPI
- acpi_disabled = 1;
- acpi_ht = 0;
-#endif
-
- /* We set the perferred console to "hvc". This is the "hypervisor
- * virtual console" driver written by the PowerPC people, which we also
- * adapted for lguest's use. */
- add_preferred_console("hvc", 0, NULL);
-
- /* Last of all, we set the power management poweroff hook to point to
- * the Guest routine to power off. */
- pm_power_off = lguest_power_off;
-
- /* Now we're set up, call start_kernel() in init/main.c and we proceed
- * to boot as normal. It never returns. */
- start_kernel();
-}
-/*
- * This marks the end of stage II of our journey, The Guest.
- *
- * It is now time for us to explore the nooks and crannies of the three Guest
- * devices and complete our understanding of the Guest in "make Drivers".
- */
diff --git a/drivers/lguest/lguest_asm.S b/drivers/lguest/lguest_asm.S
deleted file mode 100644
index 1ddcd5cd20f..00000000000
--- a/drivers/lguest/lguest_asm.S
+++ /dev/null
@@ -1,93 +0,0 @@
-#include <linux/linkage.h>
-#include <linux/lguest.h>
-#include <asm/asm-offsets.h>
-#include <asm/thread_info.h>
-#include <asm/processor-flags.h>
-
-/*G:020 This is where we begin: we have a magic signature which the launcher
- * looks for. The plan is that the Linux boot protocol will be extended with a
- * "platform type" field which will guide us here from the normal entry point,
- * but for the moment this suffices. The normal boot code uses %esi for the
- * boot header, so we do too. We convert it to a virtual address by adding
- * PAGE_OFFSET, and hand it to lguest_init() as its argument (ie. %eax).
- *
- * The .section line puts this code in .init.text so it will be discarded after
- * boot. */
-.section .init.text, "ax", @progbits
-.ascii "GenuineLguest"
- /* Set up initial stack. */
- movl $(init_thread_union+THREAD_SIZE),%esp
- movl %esi, %eax
- addl $__PAGE_OFFSET, %eax
- jmp lguest_init
-
-/*G:055 We create a macro which puts the assembler code between lgstart_ and
- * lgend_ markers. These templates are put in the .text section: they can't be
- * discarded after boot as we may need to patch modules, too. */
-.text
-#define LGUEST_PATCH(name, insns...) \
- lgstart_##name: insns; lgend_##name:; \
- .globl lgstart_##name; .globl lgend_##name
-
-LGUEST_PATCH(cli, movl $0, lguest_data+LGUEST_DATA_irq_enabled)
-LGUEST_PATCH(sti, movl $X86_EFLAGS_IF, lguest_data+LGUEST_DATA_irq_enabled)
-LGUEST_PATCH(popf, movl %eax, lguest_data+LGUEST_DATA_irq_enabled)
-LGUEST_PATCH(pushf, movl lguest_data+LGUEST_DATA_irq_enabled, %eax)
-/*:*/
-
-/* These demark the EIP range where host should never deliver interrupts. */
-.global lguest_noirq_start
-.global lguest_noirq_end
-
-/*M:004 When the Host reflects a trap or injects an interrupt into the Guest,
- * it sets the eflags interrupt bit on the stack based on
- * lguest_data.irq_enabled, so the Guest iret logic does the right thing when
- * restoring it. However, when the Host sets the Guest up for direct traps,
- * such as system calls, the processor is the one to push eflags onto the
- * stack, and the interrupt bit will be 1 (in reality, interrupts are always
- * enabled in the Guest).
- *
- * This turns out to be harmless: the only trap which should happen under Linux
- * with interrupts disabled is Page Fault (due to our lazy mapping of vmalloc
- * regions), which has to be reflected through the Host anyway. If another
- * trap *does* go off when interrupts are disabled, the Guest will panic, and
- * we'll never get to this iret! :*/
-
-/*G:045 There is one final paravirt_op that the Guest implements, and glancing
- * at it you can see why I left it to last. It's *cool*! It's in *assembler*!
- *
- * The "iret" instruction is used to return from an interrupt or trap. The
- * stack looks like this:
- * old address
- * old code segment & privilege level
- * old processor flags ("eflags")
- *
- * The "iret" instruction pops those values off the stack and restores them all
- * at once. The only problem is that eflags includes the Interrupt Flag which
- * the Guest can't change: the CPU will simply ignore it when we do an "iret".
- * So we have to copy eflags from the stack to lguest_data.irq_enabled before
- * we do the "iret".
- *
- * There are two problems with this: firstly, we need to use a register to do
- * the copy and secondly, the whole thing needs to be atomic. The first
- * problem is easy to solve: push %eax on the stack so we can use it, and then
- * restore it at the end just before the real "iret".
- *
- * The second is harder: copying eflags to lguest_data.irq_enabled will turn
- * interrupts on before we're finished, so we could be interrupted before we
- * return to userspace or wherever. Our solution to this is to surround the
- * code with lguest_noirq_start: and lguest_noirq_end: labels. We tell the
- * Host that it is *never* to interrupt us there, even if interrupts seem to be
- * enabled. */
-ENTRY(lguest_iret)
- pushl %eax
- movl 12(%esp), %eax
-lguest_noirq_start:
- /* Note the %ss: segment prefix here. Normal data accesses use the
- * "ds" segment, but that will have already been restored for whatever
- * we're returning to (such as userspace): we can't trust it. The %ss:
- * prefix makes sure we use the stack segment, which is still valid. */
- movl %eax,%ss:lguest_data+LGUEST_DATA_irq_enabled
- popl %eax
- iret
-lguest_noirq_end:
diff --git a/drivers/lguest/lguest_bus.c b/drivers/lguest/lguest_bus.c
deleted file mode 100644
index 57329788f8a..00000000000
--- a/drivers/lguest/lguest_bus.c
+++ /dev/null
@@ -1,218 +0,0 @@
-/*P:050 Lguest guests use a very simple bus for devices. It's a simple array
- * of device descriptors contained just above the top of normal memory. The
- * lguest bus is 80% tedious boilerplate code. :*/
-#include <linux/init.h>
-#include <linux/bootmem.h>
-#include <linux/lguest_bus.h>
-#include <asm/io.h>
-#include <asm/paravirt.h>
-
-static ssize_t type_show(struct device *_dev,
- struct device_attribute *attr, char *buf)
-{
- struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
- return sprintf(buf, "%hu", lguest_devices[dev->index].type);
-}
-static ssize_t features_show(struct device *_dev,
- struct device_attribute *attr, char *buf)
-{
- struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
- return sprintf(buf, "%hx", lguest_devices[dev->index].features);
-}
-static ssize_t pfn_show(struct device *_dev,
- struct device_attribute *attr, char *buf)
-{
- struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
- return sprintf(buf, "%u", lguest_devices[dev->index].pfn);
-}
-static ssize_t status_show(struct device *_dev,
- struct device_attribute *attr, char *buf)
-{
- struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
- return sprintf(buf, "%hx", lguest_devices[dev->index].status);
-}
-static ssize_t status_store(struct device *_dev, struct device_attribute *attr,
- const char *buf, size_t count)
-{
- struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
- if (sscanf(buf, "%hi", &lguest_devices[dev->index].status) != 1)
- return -EINVAL;
- return count;
-}
-static struct device_attribute lguest_dev_attrs[] = {
- __ATTR_RO(type),
- __ATTR_RO(features),
- __ATTR_RO(pfn),
- __ATTR(status, 0644, status_show, status_store),
- __ATTR_NULL
-};
-
-/*D:130 The generic bus infrastructure requires a function which says whether a
- * device matches a driver. For us, it is simple: "struct lguest_driver"
- * contains a "device_type" field which indicates what type of device it can
- * handle, so we just cast the args and compare: */
-static int lguest_dev_match(struct device *_dev, struct device_driver *_drv)
-{
- struct lguest_device *dev = container_of(_dev,struct lguest_device,dev);
- struct lguest_driver *drv = container_of(_drv,struct lguest_driver,drv);
-
- return (drv->device_type == lguest_devices[dev->index].type);
-}
-/*:*/
-
-struct lguest_bus {
- struct bus_type bus;
- struct device dev;
-};
-
-static struct lguest_bus lguest_bus = {
- .bus = {
- .name = "lguest",
- .match = lguest_dev_match,
- .dev_attrs = lguest_dev_attrs,
- },
- .dev = {
- .parent = NULL,
- .bus_id = "lguest",
- }
-};
-
-/*D:140 This is the callback which occurs once the bus infrastructure matches
- * up a device and driver, ie. in response to add_lguest_device() calling
- * device_register(), or register_lguest_driver() calling driver_register().
- *
- * At the moment it's always the latter: the devices are added first, since
- * scan_devices() is called from a "core_initcall", and the drivers themselves
- * called later as a normal "initcall". But it would work the other way too.
- *
- * So now we have the happy couple, we add the status bit to indicate that we
- * found a driver. If the driver truly loves the device, it will return
- * happiness from its probe function (ok, perhaps this wasn't my greatest
- * analogy), and we set the final "driver ok" bit so the Host sees it's all
- * green. */
-static int lguest_dev_probe(struct device *_dev)
-{
- int ret;
- struct lguest_device*dev = container_of(_dev,struct lguest_device,dev);
- struct lguest_driver*drv = container_of(dev->dev.driver,
- struct lguest_driver, drv);
-
- lguest_devices[dev->index].status |= LGUEST_DEVICE_S_DRIVER;
- ret = drv->probe(dev);
- if (ret == 0)
- lguest_devices[dev->index].status |= LGUEST_DEVICE_S_DRIVER_OK;
- return ret;
-}
-
-/* The last part of the bus infrastructure is the function lguest drivers use
- * to register themselves. Firstly, we do nothing if there's no lguest bus
- * (ie. this is not a Guest), otherwise we fill in the embedded generic "struct
- * driver" fields and call the generic driver_register(). */
-int register_lguest_driver(struct lguest_driver *drv)
-{
- if (!lguest_devices)
- return 0;
-
- drv->drv.bus = &lguest_bus.bus;
- drv->drv.name = drv->name;
- drv->drv.owner = drv->owner;
- drv->drv.probe = lguest_dev_probe;
-
- return driver_register(&drv->drv);
-}
-
-/* At the moment we build all the drivers into the kernel because they're so
- * simple: 8144 bytes for all three of them as I type this. And as the console
- * really needs to be built in, it's actually only 3527 bytes for the network
- * and block drivers.
- *
- * If they get complex it will make sense for them to be modularized, so we
- * need to explicitly export the symbol.
- *
- * I don't think non-GPL modules make sense, so it's a GPL-only export.
- */
-EXPORT_SYMBOL_GPL(register_lguest_driver);
-
-/*D:120 This is the core of the lguest bus: actually adding a new device.
- * It's a separate function because it's neater that way, and because an
- * earlier version of the code supported hotplug and unplug. They were removed
- * early on because they were never used.
- *
- * As Andrew Tridgell says, "Untested code is buggy code".
- *
- * It's worth reading this carefully: we start with an index into the array of
- * "struct lguest_device_desc"s indicating the device which is new: */
-static void add_lguest_device(unsigned int index)
-{
- struct lguest_device *new;
-
- /* Each "struct lguest_device_desc" has a "status" field, which the
- * Guest updates as the device is probed. In the worst case, the Host
- * can look at these bits to tell what part of device setup failed,
- * even if the console isn't available. */
- lguest_devices[index].status |= LGUEST_DEVICE_S_ACKNOWLEDGE;
- new = kmalloc(sizeof(struct lguest_device), GFP_KERNEL);
- if (!new) {
- printk(KERN_EMERG "Cannot allocate lguest device %u\n", index);
- lguest_devices[index].status |= LGUEST_DEVICE_S_FAILED;
- return;
- }
-
- /* The "struct lguest_device" setup is pretty straight-forward example
- * code. */
- new->index = index;
- new->private = NULL;
- memset(&new->dev, 0, sizeof(new->dev));
- new->dev.parent = &lguest_bus.dev;
- new->dev.bus = &lguest_bus.bus;
- sprintf(new->dev.bus_id, "%u", index);
-
- /* device_register() causes the bus infrastructure to look for a
- * matching driver. */
- if (device_register(&new->dev) != 0) {
- printk(KERN_EMERG "Cannot register lguest device %u\n", index);
- lguest_devices[index].status |= LGUEST_DEVICE_S_FAILED;
- kfree(new);
- }
-}
-
-/*D:110 scan_devices() simply iterates through the device array. The type 0
- * is reserved to mean "no device", and anything else means we have found a
- * device: add it. */
-static void scan_devices(void)
-{
- unsigned int i;
-
- for (i = 0; i < LGUEST_MAX_DEVICES; i++)
- if (lguest_devices[i].type)
- add_lguest_device(i);
-}
-
-/*D:100 Fairly early in boot, lguest_bus_init() is called to set up the lguest
- * bus. We check that we are a Guest by checking paravirt_ops.name: there are
- * other ways of checking, but this seems most obvious to me.
- *
- * So we can access the array of "struct lguest_device_desc"s easily, we map
- * that memory and store the pointer in the global "lguest_devices". Then we
- * register the bus with the core. Doing two registrations seems clunky to me,
- * but it seems to be the correct sysfs incantation.
- *
- * Finally we call scan_devices() which adds all the devices found in the
- * "struct lguest_device_desc" array. */
-static int __init lguest_bus_init(void)
-{
- if (strcmp(pv_info.name, "lguest") != 0)
- return 0;
-
- /* Devices are in a single page above top of "normal" mem */
- lguest_devices = lguest_map(max_pfn<<PAGE_SHIFT, 1);
-
- if (bus_register(&lguest_bus.bus) != 0
- || device_register(&lguest_bus.dev) != 0)
- panic("lguest bus registration failed");
-
- scan_devices();
- return 0;
-}
-/* Do this after core stuff, before devices. */
-postcore_initcall(lguest_bus_init);
diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c
new file mode 100644
index 00000000000..71c64837b43
--- /dev/null
+++ b/drivers/lguest/lguest_device.c
@@ -0,0 +1,373 @@
+/*P:050 Lguest guests use a very simple method to describe devices. It's a
+ * series of device descriptors contained just above the top of normal
+ * memory.
+ *
+ * We use the standard "virtio" device infrastructure, which provides us with a
+ * console, a network and a block driver. Each one expects some configuration
+ * information and a "virtqueue" mechanism to send and receive data. :*/
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/lguest_launcher.h>
+#include <linux/virtio.h>
+#include <linux/virtio_config.h>
+#include <linux/interrupt.h>
+#include <linux/virtio_ring.h>
+#include <linux/err.h>
+#include <asm/io.h>
+#include <asm/paravirt.h>
+#include <asm/lguest_hcall.h>
+
+/* The pointer to our (page) of device descriptions. */
+static void *lguest_devices;
+
+/* Unique numbering for lguest devices. */
+static unsigned int dev_index;
+
+/* For Guests, device memory can be used as normal memory, so we cast away the
+ * __iomem to quieten sparse. */
+static inline void *lguest_map(unsigned long phys_addr, unsigned long pages)
+{
+ return (__force void *)ioremap(phys_addr, PAGE_SIZE*pages);
+}
+
+static inline void lguest_unmap(void *addr)
+{
+ iounmap((__force void __iomem *)addr);
+}
+
+/*D:100 Each lguest device is just a virtio device plus a pointer to its entry
+ * in the lguest_devices page. */
+struct lguest_device {
+ struct virtio_device vdev;
+
+ /* The entry in the lguest_devices page for this device. */
+ struct lguest_device_desc *desc;
+};
+
+/* Since the virtio infrastructure hands us a pointer to the virtio_device all
+ * the time, it helps to have a curt macro to get a pointer to the struct
+ * lguest_device it's enclosed in. */
+#define to_lgdev(vdev) container_of(vdev, struct lguest_device, vdev)
+
+/*D:130
+ * Device configurations
+ *
+ * The configuration information for a device consists of a series of fields.
+ * The device will look for these fields during setup.
+ *
+ * For us these fields come immediately after that device's descriptor in the
+ * lguest_devices page.
+ *
+ * Each field starts with a "type" byte, a "length" byte, then that number of
+ * bytes of configuration information. The device descriptor tells us the
+ * total configuration length so we know when we've reached the last field. */
+
+/* type + length bytes */
+#define FHDR_LEN 2
+
+/* This finds the first field of a given type for a device's configuration. */
+static void *lg_find(struct virtio_device *vdev, u8 type, unsigned int *len)
+{
+ struct lguest_device_desc *desc = to_lgdev(vdev)->desc;
+ int i;
+
+ for (i = 0; i < desc->config_len; i += FHDR_LEN + desc->config[i+1]) {
+ if (desc->config[i] == type) {
+ /* Mark it used, so Host can know we looked at it, and
+ * also so we won't find the same one twice. */
+ desc->config[i] |= 0x80;
+ /* Remember, the second byte is the length. */
+ *len = desc->config[i+1];
+ /* We return a pointer to the field header. */
+ return desc->config + i;
+ }
+ }
+
+ /* Not found: return NULL for failure. */
+ return NULL;
+}
+
+/* Once they've found a field, getting a copy of it is easy. */
+static void lg_get(struct virtio_device *vdev, void *token,
+ void *buf, unsigned len)
+{
+ /* Check they didn't ask for more than the length of the field! */
+ BUG_ON(len > ((u8 *)token)[1]);
+ memcpy(buf, token + FHDR_LEN, len);
+}
+
+/* Setting the contents is also trivial. */
+static void lg_set(struct virtio_device *vdev, void *token,
+ const void *buf, unsigned len)
+{
+ BUG_ON(len > ((u8 *)token)[1]);
+ memcpy(token + FHDR_LEN, buf, len);
+}
+
+/* The operations to get and set the status word just access the status field
+ * of the device descriptor. */
+static u8 lg_get_status(struct virtio_device *vdev)
+{
+ return to_lgdev(vdev)->desc->status;
+}
+
+static void lg_set_status(struct virtio_device *vdev, u8 status)
+{
+ to_lgdev(vdev)->desc->status = status;
+}
+
+/*
+ * Virtqueues
+ *
+ * The other piece of infrastructure virtio needs is a "virtqueue": a way of
+ * the Guest device registering buffers for the other side to read from or
+ * write into (ie. send and receive buffers). Each device can have multiple
+ * virtqueues: for example the console has one queue for sending and one for
+ * receiving.
+ *
+ * Fortunately for us, a very fast shared-memory-plus-descriptors virtqueue
+ * already exists in virtio_ring.c. We just need to connect it up.
+ *
+ * We start with the information we need to keep about each virtqueue.
+ */
+
+/*D:140 This is the information we remember about each virtqueue. */
+struct lguest_vq_info
+{
+ /* A copy of the information contained in the device config. */
+ struct lguest_vqconfig config;
+
+ /* The address where we mapped the virtio ring, so we can unmap it. */
+ void *pages;
+};
+
+/* When the virtio_ring code wants to prod the Host, it calls us here and we
+ * make a hypercall. We hand the page number of the virtqueue so the Host
+ * knows which virtqueue we're talking about. */
+static void lg_notify(struct virtqueue *vq)
+{
+ /* We store our virtqueue information in the "priv" pointer of the
+ * virtqueue structure. */
+ struct lguest_vq_info *lvq = vq->priv;
+
+ hcall(LHCALL_NOTIFY, lvq->config.pfn << PAGE_SHIFT, 0, 0);
+}
+
+/* This routine finds the first virtqueue described in the configuration of
+ * this device and sets it up.
+ *
+ * This is kind of an ugly duckling. It'd be nicer to have a standard
+ * representation of a virtqueue in the configuration space, but it seems that
+ * everyone wants to do it differently. The KVM guys want the Guest to
+ * allocate its own pages and tell the Host where they are, but for lguest it's
+ * simpler for the Host to simply tell us where the pages are.
+ *
+ * So we provide devices with a "find virtqueue and set it up" function. */
+static struct virtqueue *lg_find_vq(struct virtio_device *vdev,
+ bool (*callback)(struct virtqueue *vq))
+{
+ struct lguest_vq_info *lvq;
+ struct virtqueue *vq;
+ unsigned int len;
+ void *token;
+ int err;
+
+ /* Look for a field of the correct type to mark a virtqueue. Note that
+ * if this succeeds, then the type will be changed so it won't be found
+ * again, and future lg_find_vq() calls will find the next
+ * virtqueue (if any). */
+ token = vdev->config->find(vdev, VIRTIO_CONFIG_F_VIRTQUEUE, &len);
+ if (!token)
+ return ERR_PTR(-ENOENT);
+
+ lvq = kmalloc(sizeof(*lvq), GFP_KERNEL);
+ if (!lvq)
+ return ERR_PTR(-ENOMEM);
+
+ /* Note: we could use a configuration space inside here, just like we
+ * do for the device. This would allow expansion in future, because
+ * our configuration system is designed to be expansible. But this is
+ * way easier. */
+ if (len != sizeof(lvq->config)) {
+ dev_err(&vdev->dev, "Unexpected virtio config len %u\n", len);
+ err = -EIO;
+ goto free_lvq;
+ }
+ /* Make a copy of the "struct lguest_vqconfig" field. We need a copy
+ * because the config space might not be aligned correctly. */
+ vdev->config->get(vdev, token, &lvq->config, sizeof(lvq->config));
+
+ /* Figure out how many pages the ring will take, and map that memory */
+ lvq->pages = lguest_map((unsigned long)lvq->config.pfn << PAGE_SHIFT,
+ DIV_ROUND_UP(vring_size(lvq->config.num),
+ PAGE_SIZE));
+ if (!lvq->pages) {
+ err = -ENOMEM;
+ goto free_lvq;
+ }
+
+ /* OK, tell virtio_ring.c to set up a virtqueue now we know its size
+ * and we've got a pointer to its pages. */
+ vq = vring_new_virtqueue(lvq->config.num, vdev, lvq->pages,
+ lg_notify, callback);
+ if (!vq) {
+ err = -ENOMEM;
+ goto unmap;
+ }
+
+ /* Tell the interrupt for this virtqueue to go to the virtio_ring
+ * interrupt handler. */
+ /* FIXME: We used to have a flag for the Host to tell us we could use
+ * the interrupt as a source of randomness: it'd be nice to have that
+ * back.. */
+ err = request_irq(lvq->config.irq, vring_interrupt, IRQF_SHARED,
+ vdev->dev.bus_id, vq);
+ if (err)
+ goto destroy_vring;
+
+ /* Last of all we hook up our 'struct lguest_vq_info" to the
+ * virtqueue's priv pointer. */
+ vq->priv = lvq;
+ return vq;
+
+destroy_vring:
+ vring_del_virtqueue(vq);
+unmap:
+ lguest_unmap(lvq->pages);
+free_lvq:
+ kfree(lvq);
+ return ERR_PTR(err);
+}
+/*:*/
+
+/* Cleaning up a virtqueue is easy */
+static void lg_del_vq(struct virtqueue *vq)
+{
+ struct lguest_vq_info *lvq = vq->priv;
+
+ /* Tell virtio_ring.c to free the virtqueue. */
+ vring_del_virtqueue(vq);
+ /* Unmap the pages containing the ring. */
+ lguest_unmap(lvq->pages);
+ /* Free our own queue information. */
+ kfree(lvq);
+}
+
+/* The ops structure which hooks everything together. */
+static struct virtio_config_ops lguest_config_ops = {
+ .find = lg_find,
+ .get = lg_get,
+ .set = lg_set,
+ .get_status = lg_get_status,
+ .set_status = lg_set_status,
+ .find_vq = lg_find_vq,
+ .del_vq = lg_del_vq,
+};
+
+/* The root device for the lguest virtio devices. This makes them appear as
+ * /sys/devices/lguest/0,1,2 not /sys/devices/0,1,2. */
+static struct device lguest_root = {
+ .parent = NULL,
+ .bus_id = "lguest",
+};
+
+/*D:120 This is the core of the lguest bus: actually adding a new device.
+ * It's a separate function because it's neater that way, and because an
+ * earlier version of the code supported hotplug and unplug. They were removed
+ * early on because they were never used.
+ *
+ * As Andrew Tridgell says, "Untested code is buggy code".
+ *
+ * It's worth reading this carefully: we start with a pointer to the new device
+ * descriptor in the "lguest_devices" page. */
+static void add_lguest_device(struct lguest_device_desc *d)
+{
+ struct lguest_device *ldev;
+
+ ldev = kzalloc(sizeof(*ldev), GFP_KERNEL);
+ if (!ldev) {
+ printk(KERN_EMERG "Cannot allocate lguest dev %u\n",
+ dev_index++);
+ return;
+ }
+
+ /* This devices' parent is the lguest/ dir. */
+ ldev->vdev.dev.parent = &lguest_root;
+ /* We have a unique device index thanks to the dev_index counter. */
+ ldev->vdev.index = dev_index++;
+ /* The device type comes straight from the descriptor. There's also a
+ * device vendor field in the virtio_device struct, which we leave as
+ * 0. */
+ ldev->vdev.id.device = d->type;
+ /* We have a simple set of routines for querying the device's
+ * configuration information and setting its status. */
+ ldev->vdev.config = &lguest_config_ops;
+ /* And we remember the device's descriptor for lguest_config_ops. */
+ ldev->desc = d;
+
+ /* register_virtio_device() sets up the generic fields for the struct
+ * virtio_device and calls device_register(). This makes the bus
+ * infrastructure look for a matching driver. */
+ if (register_virtio_device(&ldev->vdev) != 0) {
+ printk(KERN_ERR "Failed to register lguest device %u\n",
+ ldev->vdev.index);
+ kfree(ldev);
+ }
+}
+
+/*D:110 scan_devices() simply iterates through the device page. The type 0 is
+ * reserved to mean "end of devices". */
+static void scan_devices(void)
+{
+ unsigned int i;
+ struct lguest_device_desc *d;
+
+ /* We start at the page beginning, and skip over each entry. */
+ for (i = 0; i < PAGE_SIZE; i += sizeof(*d) + d->config_len) {
+ d = lguest_devices + i;
+
+ /* Once we hit a zero, stop. */
+ if (d->type == 0)
+ break;
+
+ add_lguest_device(d);
+ }
+}
+
+/*D:105 Fairly early in boot, lguest_devices_init() is called to set up the
+ * lguest device infrastructure. We check that we are a Guest by checking
+ * pv_info.name: there are other ways of checking, but this seems most
+ * obvious to me.
+ *
+ * So we can access the "struct lguest_device_desc"s easily, we map that memory
+ * and store the pointer in the global "lguest_devices". Then we register a
+ * root device from which all our devices will hang (this seems to be the
+ * correct sysfs incantation).
+ *
+ * Finally we call scan_devices() which adds all the devices found in the
+ * lguest_devices page. */
+static int __init lguest_devices_init(void)
+{
+ if (strcmp(pv_info.name, "lguest") != 0)
+ return 0;
+
+ if (device_register(&lguest_root) != 0)
+ panic("Could not register lguest root");
+
+ /* Devices are in a single page above top of "normal" mem */
+ lguest_devices = lguest_map(max_pfn<<PAGE_SHIFT, 1);
+
+ scan_devices();
+ return 0;
+}
+/* We do this after core stuff, but before the drivers. */
+postcore_initcall(lguest_devices_init);
+
+/*D:150 At this point in the journey we used to now wade through the lguest
+ * devices themselves: net, block and console. Since they're all now virtio
+ * devices rather than lguest-specific, I've decided to ignore them. Mostly,
+ * they're kind of boring. But this does mean you'll never experience the
+ * thrill of reading the forbidden love scene buried deep in the block driver.
+ *
+ * "make Launcher" beckons, where we answer questions like "Where do Guests
+ * come from?", and "What do you do when someone asks for optimization?". */
diff --git a/drivers/lguest/lguest_user.c b/drivers/lguest/lguest_user.c
index 80d1b58c769..ee405b38383 100644
--- a/drivers/lguest/lguest_user.c
+++ b/drivers/lguest/lguest_user.c
@@ -1,73 +1,17 @@
/*P:200 This contains all the /dev/lguest code, whereby the userspace launcher
* controls and communicates with the Guest. For example, the first write will
- * tell us the memory size, pagetable, entry point and kernel address offset.
- * A read will run the Guest until a signal is pending (-EINTR), or the Guest
- * does a DMA out to the Launcher. Writes are also used to get a DMA buffer
- * registered by the Guest and to send the Guest an interrupt. :*/
+ * tell us the Guest's memory layout, pagetable, entry point and kernel address
+ * offset. A read will run the Guest until something happens, such as a signal
+ * or the Guest doing a NOTIFY out to the Launcher. :*/
#include <linux/uaccess.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include "lg.h"
-/*L:030 setup_regs() doesn't really belong in this file, but it gives us an
- * early glimpse deeper into the Host so it's worth having here.
- *
- * Most of the Guest's registers are left alone: we used get_zeroed_page() to
- * allocate the structure, so they will be 0. */
-static void setup_regs(struct lguest_regs *regs, unsigned long start)
-{
- /* There are four "segment" registers which the Guest needs to boot:
- * The "code segment" register (cs) refers to the kernel code segment
- * __KERNEL_CS, and the "data", "extra" and "stack" segment registers
- * refer to the kernel data segment __KERNEL_DS.
- *
- * The privilege level is packed into the lower bits. The Guest runs
- * at privilege level 1 (GUEST_PL).*/
- regs->ds = regs->es = regs->ss = __KERNEL_DS|GUEST_PL;
- regs->cs = __KERNEL_CS|GUEST_PL;
-
- /* The "eflags" register contains miscellaneous flags. Bit 1 (0x002)
- * is supposed to always be "1". Bit 9 (0x200) controls whether
- * interrupts are enabled. We always leave interrupts enabled while
- * running the Guest. */
- regs->eflags = 0x202;
-
- /* The "Extended Instruction Pointer" register says where the Guest is
- * running. */
- regs->eip = start;
-
- /* %esi points to our boot information, at physical address 0, so don't
- * touch it. */
-}
-
-/*L:310 To send DMA into the Guest, the Launcher needs to be able to ask for a
- * DMA buffer. This is done by writing LHREQ_GETDMA and the key to
- * /dev/lguest. */
-static long user_get_dma(struct lguest *lg, const u32 __user *input)
-{
- unsigned long key, udma, irq;
-
- /* Fetch the key they wrote to us. */
- if (get_user(key, input) != 0)
- return -EFAULT;
- /* Look for a free Guest DMA buffer bound to that key. */
- udma = get_dma_buffer(lg, key, &irq);
- if (!udma)
- return -ENOENT;
-
- /* We need to tell the Launcher what interrupt the Guest expects after
- * the buffer is filled. We stash it in udma->used_len. */
- lgwrite_u32(lg, udma + offsetof(struct lguest_dma, used_len), irq);
-
- /* The (guest-physical) address of the DMA buffer is returned from
- * the write(). */
- return udma;
-}
-
/*L:315 To force the Guest to stop running and return to the Launcher, the
* Waker sets writes LHREQ_BREAK and the value "1" to /dev/lguest. The
* Launcher then writes LHREQ_BREAK and "0" to release the Waker. */
-static int break_guest_out(struct lguest *lg, const u32 __user *input)
+static int break_guest_out(struct lguest *lg, const unsigned long __user *input)
{
unsigned long on;
@@ -90,9 +34,9 @@ static int break_guest_out(struct lguest *lg, const u32 __user *input)
/*L:050 Sending an interrupt is done by writing LHREQ_IRQ and an interrupt
* number to /dev/lguest. */
-static int user_send_irq(struct lguest *lg, const u32 __user *input)
+static int user_send_irq(struct lguest *lg, const unsigned long __user *input)
{
- u32 irq;
+ unsigned long irq;
if (get_user(irq, input) != 0)
return -EFAULT;
@@ -133,17 +77,19 @@ static ssize_t read(struct file *file, char __user *user, size_t size,loff_t*o)
return len;
}
- /* If we returned from read() last time because the Guest sent DMA,
+ /* If we returned from read() last time because the Guest notified,
* clear the flag. */
- if (lg->dma_is_pending)
- lg->dma_is_pending = 0;
+ if (lg->pending_notify)
+ lg->pending_notify = 0;
/* Run the Guest until something interesting happens. */
return run_guest(lg, (unsigned long __user *)user);
}
-/*L:020 The initialization write supplies 4 32-bit values (in addition to the
- * 32-bit LHREQ_INITIALIZE value). These are:
+/*L:020 The initialization write supplies 4 pointer sized (32 or 64 bit)
+ * values (in addition to the LHREQ_INITIALIZE value). These are:
+ *
+ * base: The start of the Guest-physical memory inside the Launcher memory.
*
* pfnlimit: The highest (Guest-physical) page number the Guest should be
* allowed to access. The Launcher has to live in Guest memory, so it sets
@@ -153,23 +99,17 @@ static ssize_t read(struct file *file, char __user *user, size_t size,loff_t*o)
* pagetables (which are set up by the Launcher).
*
* start: The first instruction to execute ("eip" in x86-speak).
- *
- * page_offset: The PAGE_OFFSET constant in the Guest kernel. We should
- * probably wean the code off this, but it's a very useful constant! Any
- * address above this is within the Guest kernel, and any kernel address can
- * quickly converted from physical to virtual by adding PAGE_OFFSET. It's
- * 0xC0000000 (3G) by default, but it's configurable at kernel build time.
*/
-static int initialize(struct file *file, const u32 __user *input)
+static int initialize(struct file *file, const unsigned long __user *input)
{
/* "struct lguest" contains everything we (the Host) know about a
* Guest. */
struct lguest *lg;
- int err, i;
- u32 args[4];
+ int err;
+ unsigned long args[4];
- /* We grab the Big Lguest lock, which protects the global array
- * "lguests" and multiple simultaneous initializations. */
+ /* We grab the Big Lguest lock, which protects against multiple
+ * simultaneous initializations. */
mutex_lock(&lguest_lock);
/* You can't initialize twice! Close the device and start again... */
if (file->private_data) {
@@ -182,20 +122,15 @@ static int initialize(struct file *file, const u32 __user *input)
goto unlock;
}
- /* Find an unused guest. */
- i = find_free_guest();
- if (i < 0) {
- err = -ENOSPC;
+ lg = kzalloc(sizeof(*lg), GFP_KERNEL);
+ if (!lg) {
+ err = -ENOMEM;
goto unlock;
}
- /* OK, we have an index into the "lguest" array: "lg" is a convenient
- * pointer. */
- lg = &lguests[i];
/* Populate the easy fields of our "struct lguest" */
- lg->guestid = i;
- lg->pfn_limit = args[0];
- lg->page_offset = args[3];
+ lg->mem_base = (void __user *)(long)args[0];
+ lg->pfn_limit = args[1];
/* We need a complete page for the Guest registers: they are accessible
* to the Guest and we can only grant it access to whole pages. */
@@ -210,17 +145,13 @@ static int initialize(struct file *file, const u32 __user *input)
/* Initialize the Guest's shadow page tables, using the toplevel
* address the Launcher gave us. This allocates memory, so can
* fail. */
- err = init_guest_pagetable(lg, args[1]);
+ err = init_guest_pagetable(lg, args[2]);
if (err)
goto free_regs;
/* Now we initialize the Guest's registers, handing it the start
* address. */
- setup_regs(lg->regs, args[2]);
-
- /* There are a couple of GDT entries the Guest expects when first
- * booting. */
- setup_guest_gdt(lg);
+ lguest_arch_setup_regs(lg, args[3]);
/* The timer for lguest's clock needs initialization. */
init_clockdev(lg);
@@ -260,18 +191,19 @@ unlock:
/*L:010 The first operation the Launcher does must be a write. All writes
* start with a 32 bit number: for the first write this must be
* LHREQ_INITIALIZE to set up the Guest. After that the Launcher can use
- * writes of other values to get DMA buffers and send interrupts. */
-static ssize_t write(struct file *file, const char __user *input,
+ * writes of other values to send interrupts. */
+static ssize_t write(struct file *file, const char __user *in,
size_t size, loff_t *off)
{
/* Once the guest is initialized, we hold the "struct lguest" in the
* file private data. */
struct lguest *lg = file->private_data;
- u32 req;
+ const unsigned long __user *input = (const unsigned long __user *)in;
+ unsigned long req;
if (get_user(req, input) != 0)
return -EFAULT;
- input += sizeof(req);
+ input++;
/* If you haven't initialized, you must do that first. */
if (req != LHREQ_INITIALIZE && !lg)
@@ -287,13 +219,11 @@ static ssize_t write(struct file *file, const char __user *input,
switch (req) {
case LHREQ_INITIALIZE:
- return initialize(file, (const u32 __user *)input);
- case LHREQ_GETDMA:
- return user_get_dma(lg, (const u32 __user *)input);
+ return initialize(file, input);
case LHREQ_IRQ:
- return user_send_irq(lg, (const u32 __user *)input);
+ return user_send_irq(lg, input);
case LHREQ_BREAK:
- return break_guest_out(lg, (const u32 __user *)input);
+ return break_guest_out(lg, input);
default:
return -EINVAL;
}
@@ -319,8 +249,6 @@ static int close(struct inode *inode, struct file *file)
mutex_lock(&lguest_lock);
/* Cancels the hrtimer set via LHCALL_SET_CLOCKEVENT. */
hrtimer_cancel(&lg->hrt);
- /* Free any DMA buffers the Guest had bound. */
- release_all_dma(lg);
/* Free up the shadow page tables for the Guest. */
free_guest_pagetable(lg);
/* Now all the memory cleanups are done, it's safe to release the
diff --git a/drivers/lguest/page_tables.c b/drivers/lguest/page_tables.c
index b7a924ace68..2a45f0691c9 100644
--- a/drivers/lguest/page_tables.c
+++ b/drivers/lguest/page_tables.c
@@ -13,6 +13,7 @@
#include <linux/random.h>
#include <linux/percpu.h>
#include <asm/tlbflush.h>
+#include <asm/uaccess.h>
#include "lg.h"
/*M:008 We hold reference to pages, which prevents them from being swapped.
@@ -44,44 +45,32 @@
* (vii) Setting up the page tables initially.
:*/
-/* Pages a 4k long, and each page table entry is 4 bytes long, giving us 1024
- * (or 2^10) entries per page. */
-#define PTES_PER_PAGE_SHIFT 10
-#define PTES_PER_PAGE (1 << PTES_PER_PAGE_SHIFT)
/* 1024 entries in a page table page maps 1024 pages: 4MB. The Switcher is
* conveniently placed at the top 4MB, so it uses a separate, complete PTE
* page. */
-#define SWITCHER_PGD_INDEX (PTES_PER_PAGE - 1)
+#define SWITCHER_PGD_INDEX (PTRS_PER_PGD - 1)
/* We actually need a separate PTE page for each CPU. Remember that after the
* Switcher code itself comes two pages for each CPU, and we don't want this
* CPU's guest to see the pages of any other CPU. */
-static DEFINE_PER_CPU(spte_t *, switcher_pte_pages);
+static DEFINE_PER_CPU(pte_t *, switcher_pte_pages);
#define switcher_pte_page(cpu) per_cpu(switcher_pte_pages, cpu)
/*H:320 With our shadow and Guest types established, we need to deal with
* them: the page table code is curly enough to need helper functions to keep
* it clear and clean.
*
- * The first helper takes a virtual address, and says which entry in the top
- * level page table deals with that address. Since each top level entry deals
- * with 4M, this effectively divides by 4M. */
-static unsigned vaddr_to_pgd_index(unsigned long vaddr)
-{
- return vaddr >> (PAGE_SHIFT + PTES_PER_PAGE_SHIFT);
-}
-
-/* There are two functions which return pointers to the shadow (aka "real")
+ * There are two functions which return pointers to the shadow (aka "real")
* page tables.
*
* spgd_addr() takes the virtual address and returns a pointer to the top-level
* page directory entry for that address. Since we keep track of several page
* tables, the "i" argument tells us which one we're interested in (it's
* usually the current one). */
-static spgd_t *spgd_addr(struct lguest *lg, u32 i, unsigned long vaddr)
+static pgd_t *spgd_addr(struct lguest *lg, u32 i, unsigned long vaddr)
{
- unsigned int index = vaddr_to_pgd_index(vaddr);
+ unsigned int index = pgd_index(vaddr);
/* We kill any Guest trying to touch the Switcher addresses. */
if (index >= SWITCHER_PGD_INDEX) {
@@ -95,28 +84,28 @@ static spgd_t *spgd_addr(struct lguest *lg, u32 i, unsigned long vaddr)
/* This routine then takes the PGD entry given above, which contains the
* address of the PTE page. It then returns a pointer to the PTE entry for the
* given address. */
-static spte_t *spte_addr(struct lguest *lg, spgd_t spgd, unsigned long vaddr)
+static pte_t *spte_addr(struct lguest *lg, pgd_t spgd, unsigned long vaddr)
{
- spte_t *page = __va(spgd.pfn << PAGE_SHIFT);
+ pte_t *page = __va(pgd_pfn(spgd) << PAGE_SHIFT);
/* You should never call this if the PGD entry wasn't valid */
- BUG_ON(!(spgd.flags & _PAGE_PRESENT));
- return &page[(vaddr >> PAGE_SHIFT) % PTES_PER_PAGE];
+ BUG_ON(!(pgd_flags(spgd) & _PAGE_PRESENT));
+ return &page[(vaddr >> PAGE_SHIFT) % PTRS_PER_PTE];
}
/* These two functions just like the above two, except they access the Guest
* page tables. Hence they return a Guest address. */
static unsigned long gpgd_addr(struct lguest *lg, unsigned long vaddr)
{
- unsigned int index = vaddr >> (PAGE_SHIFT + PTES_PER_PAGE_SHIFT);
- return lg->pgdirs[lg->pgdidx].cr3 + index * sizeof(gpgd_t);
+ unsigned int index = vaddr >> (PGDIR_SHIFT);
+ return lg->pgdirs[lg->pgdidx].gpgdir + index * sizeof(pgd_t);
}
static unsigned long gpte_addr(struct lguest *lg,
- gpgd_t gpgd, unsigned long vaddr)
+ pgd_t gpgd, unsigned long vaddr)
{
- unsigned long gpage = gpgd.pfn << PAGE_SHIFT;
- BUG_ON(!(gpgd.flags & _PAGE_PRESENT));
- return gpage + ((vaddr>>PAGE_SHIFT) % PTES_PER_PAGE) * sizeof(gpte_t);
+ unsigned long gpage = pgd_pfn(gpgd) << PAGE_SHIFT;
+ BUG_ON(!(pgd_flags(gpgd) & _PAGE_PRESENT));
+ return gpage + ((vaddr>>PAGE_SHIFT) % PTRS_PER_PTE) * sizeof(pte_t);
}
/*H:350 This routine takes a page number given by the Guest and converts it to
@@ -149,53 +138,55 @@ static unsigned long get_pfn(unsigned long virtpfn, int write)
* entry can be a little tricky. The flags are (almost) the same, but the
* Guest PTE contains a virtual page number: the CPU needs the real page
* number. */
-static spte_t gpte_to_spte(struct lguest *lg, gpte_t gpte, int write)
+static pte_t gpte_to_spte(struct lguest *lg, pte_t gpte, int write)
{
- spte_t spte;
- unsigned long pfn;
+ unsigned long pfn, base, flags;
/* The Guest sets the global flag, because it thinks that it is using
* PGE. We only told it to use PGE so it would tell us whether it was
* flushing a kernel mapping or a userspace mapping. We don't actually
* use the global bit, so throw it away. */
- spte.flags = (gpte.flags & ~_PAGE_GLOBAL);
+ flags = (pte_flags(gpte) & ~_PAGE_GLOBAL);
+
+ /* The Guest's pages are offset inside the Launcher. */
+ base = (unsigned long)lg->mem_base / PAGE_SIZE;
/* We need a temporary "unsigned long" variable to hold the answer from
* get_pfn(), because it returns 0xFFFFFFFF on failure, which wouldn't
* fit in spte.pfn. get_pfn() finds the real physical number of the
* page, given the virtual number. */
- pfn = get_pfn(gpte.pfn, write);
+ pfn = get_pfn(base + pte_pfn(gpte), write);
if (pfn == -1UL) {
- kill_guest(lg, "failed to get page %u", gpte.pfn);
+ kill_guest(lg, "failed to get page %lu", pte_pfn(gpte));
/* When we destroy the Guest, we'll go through the shadow page
* tables and release_pte() them. Make sure we don't think
* this one is valid! */
- spte.flags = 0;
+ flags = 0;
}
- /* Now we assign the page number, and our shadow PTE is complete. */
- spte.pfn = pfn;
- return spte;
+ /* Now we assemble our shadow PTE from the page number and flags. */
+ return pfn_pte(pfn, __pgprot(flags));
}
/*H:460 And to complete the chain, release_pte() looks like this: */
-static void release_pte(spte_t pte)
+static void release_pte(pte_t pte)
{
/* Remember that get_user_pages() took a reference to the page, in
* get_pfn()? We have to put it back now. */
- if (pte.flags & _PAGE_PRESENT)
- put_page(pfn_to_page(pte.pfn));
+ if (pte_flags(pte) & _PAGE_PRESENT)
+ put_page(pfn_to_page(pte_pfn(pte)));
}
/*:*/
-static void check_gpte(struct lguest *lg, gpte_t gpte)
+static void check_gpte(struct lguest *lg, pte_t gpte)
{
- if ((gpte.flags & (_PAGE_PWT|_PAGE_PSE)) || gpte.pfn >= lg->pfn_limit)
+ if ((pte_flags(gpte) & (_PAGE_PWT|_PAGE_PSE))
+ || pte_pfn(gpte) >= lg->pfn_limit)
kill_guest(lg, "bad page table entry");
}
-static void check_gpgd(struct lguest *lg, gpgd_t gpgd)
+static void check_gpgd(struct lguest *lg, pgd_t gpgd)
{
- if ((gpgd.flags & ~_PAGE_TABLE) || gpgd.pfn >= lg->pfn_limit)
+ if ((pgd_flags(gpgd) & ~_PAGE_TABLE) || pgd_pfn(gpgd) >= lg->pfn_limit)
kill_guest(lg, "bad page directory entry");
}
@@ -211,21 +202,21 @@ static void check_gpgd(struct lguest *lg, gpgd_t gpgd)
* true. */
int demand_page(struct lguest *lg, unsigned long vaddr, int errcode)
{
- gpgd_t gpgd;
- spgd_t *spgd;
+ pgd_t gpgd;
+ pgd_t *spgd;
unsigned long gpte_ptr;
- gpte_t gpte;
- spte_t *spte;
+ pte_t gpte;
+ pte_t *spte;
/* First step: get the top-level Guest page table entry. */
- gpgd = mkgpgd(lgread_u32(lg, gpgd_addr(lg, vaddr)));
+ gpgd = lgread(lg, gpgd_addr(lg, vaddr), pgd_t);
/* Toplevel not present? We can't map it in. */
- if (!(gpgd.flags & _PAGE_PRESENT))
+ if (!(pgd_flags(gpgd) & _PAGE_PRESENT))
return 0;
/* Now look at the matching shadow entry. */
spgd = spgd_addr(lg, lg->pgdidx, vaddr);
- if (!(spgd->flags & _PAGE_PRESENT)) {
+ if (!(pgd_flags(*spgd) & _PAGE_PRESENT)) {
/* No shadow entry: allocate a new shadow PTE page. */
unsigned long ptepage = get_zeroed_page(GFP_KERNEL);
/* This is not really the Guest's fault, but killing it is
@@ -238,34 +229,35 @@ int demand_page(struct lguest *lg, unsigned long vaddr, int errcode)
check_gpgd(lg, gpgd);
/* And we copy the flags to the shadow PGD entry. The page
* number in the shadow PGD is the page we just allocated. */
- spgd->raw.val = (__pa(ptepage) | gpgd.flags);
+ *spgd = __pgd(__pa(ptepage) | pgd_flags(gpgd));
}
/* OK, now we look at the lower level in the Guest page table: keep its
* address, because we might update it later. */
gpte_ptr = gpte_addr(lg, gpgd, vaddr);
- gpte = mkgpte(lgread_u32(lg, gpte_ptr));
+ gpte = lgread(lg, gpte_ptr, pte_t);
/* If this page isn't in the Guest page tables, we can't page it in. */
- if (!(gpte.flags & _PAGE_PRESENT))
+ if (!(pte_flags(gpte) & _PAGE_PRESENT))
return 0;
/* Check they're not trying to write to a page the Guest wants
* read-only (bit 2 of errcode == write). */
- if ((errcode & 2) && !(gpte.flags & _PAGE_RW))
+ if ((errcode & 2) && !(pte_flags(gpte) & _PAGE_RW))
return 0;
/* User access to a kernel page? (bit 3 == user access) */
- if ((errcode & 4) && !(gpte.flags & _PAGE_USER))
+ if ((errcode & 4) && !(pte_flags(gpte) & _PAGE_USER))
return 0;
/* Check that the Guest PTE flags are OK, and the page number is below
* the pfn_limit (ie. not mapping the Launcher binary). */
check_gpte(lg, gpte);
/* Add the _PAGE_ACCESSED and (for a write) _PAGE_DIRTY flag */
- gpte.flags |= _PAGE_ACCESSED;
+ gpte = pte_mkyoung(gpte);
+
if (errcode & 2)
- gpte.flags |= _PAGE_DIRTY;
+ gpte = pte_mkdirty(gpte);
/* Get the pointer to the shadow PTE entry we're going to set. */
spte = spte_addr(lg, *spgd, vaddr);
@@ -275,21 +267,18 @@ int demand_page(struct lguest *lg, unsigned long vaddr, int errcode)
/* If this is a write, we insist that the Guest page is writable (the
* final arg to gpte_to_spte()). */
- if (gpte.flags & _PAGE_DIRTY)
+ if (pte_dirty(gpte))
*spte = gpte_to_spte(lg, gpte, 1);
- else {
+ else
/* If this is a read, don't set the "writable" bit in the page
* table entry, even if the Guest says it's writable. That way
* we come back here when a write does actually ocur, so we can
* update the Guest's _PAGE_DIRTY flag. */
- gpte_t ro_gpte = gpte;
- ro_gpte.flags &= ~_PAGE_RW;
- *spte = gpte_to_spte(lg, ro_gpte, 0);
- }
+ *spte = gpte_to_spte(lg, pte_wrprotect(gpte), 0);
/* Finally, we write the Guest PTE entry back: we've set the
* _PAGE_ACCESSED and maybe the _PAGE_DIRTY flags. */
- lgwrite_u32(lg, gpte_ptr, gpte.raw.val);
+ lgwrite(lg, gpte_ptr, pte_t, gpte);
/* We succeeded in mapping the page! */
return 1;
@@ -305,17 +294,18 @@ int demand_page(struct lguest *lg, unsigned long vaddr, int errcode)
* mapped by the shadow page tables, and is it writable? */
static int page_writable(struct lguest *lg, unsigned long vaddr)
{
- spgd_t *spgd;
+ pgd_t *spgd;
unsigned long flags;
/* Look at the top level entry: is it present? */
spgd = spgd_addr(lg, lg->pgdidx, vaddr);
- if (!(spgd->flags & _PAGE_PRESENT))
+ if (!(pgd_flags(*spgd) & _PAGE_PRESENT))
return 0;
/* Check the flags on the pte entry itself: it must be present and
* writable. */
- flags = spte_addr(lg, *spgd, vaddr)->flags;
+ flags = pte_flags(*(spte_addr(lg, *spgd, vaddr)));
+
return (flags & (_PAGE_PRESENT|_PAGE_RW)) == (_PAGE_PRESENT|_PAGE_RW);
}
@@ -329,22 +319,22 @@ void pin_page(struct lguest *lg, unsigned long vaddr)
}
/*H:450 If we chase down the release_pgd() code, it looks like this: */
-static void release_pgd(struct lguest *lg, spgd_t *spgd)
+static void release_pgd(struct lguest *lg, pgd_t *spgd)
{
/* If the entry's not present, there's nothing to release. */
- if (spgd->flags & _PAGE_PRESENT) {
+ if (pgd_flags(*spgd) & _PAGE_PRESENT) {
unsigned int i;
/* Converting the pfn to find the actual PTE page is easy: turn
* the page number into a physical address, then convert to a
* virtual address (easy for kernel pages like this one). */
- spte_t *ptepage = __va(spgd->pfn << PAGE_SHIFT);
+ pte_t *ptepage = __va(pgd_pfn(*spgd) << PAGE_SHIFT);
/* For each entry in the page, we might need to release it. */
- for (i = 0; i < PTES_PER_PAGE; i++)
+ for (i = 0; i < PTRS_PER_PTE; i++)
release_pte(ptepage[i]);
/* Now we can free the page of PTEs */
free_page((long)ptepage);
/* And zero out the PGD entry we we never release it twice. */
- spgd->raw.val = 0;
+ *spgd = __pgd(0);
}
}
@@ -356,7 +346,7 @@ static void flush_user_mappings(struct lguest *lg, int idx)
{
unsigned int i;
/* Release every pgd entry up to the kernel's address. */
- for (i = 0; i < vaddr_to_pgd_index(lg->page_offset); i++)
+ for (i = 0; i < pgd_index(lg->kernel_address); i++)
release_pgd(lg, lg->pgdirs[idx].pgdir + i);
}
@@ -369,6 +359,25 @@ void guest_pagetable_flush_user(struct lguest *lg)
}
/*:*/
+/* We walk down the guest page tables to get a guest-physical address */
+unsigned long guest_pa(struct lguest *lg, unsigned long vaddr)
+{
+ pgd_t gpgd;
+ pte_t gpte;
+
+ /* First step: get the top-level Guest page table entry. */
+ gpgd = lgread(lg, gpgd_addr(lg, vaddr), pgd_t);
+ /* Toplevel not present? We can't map it in. */
+ if (!(pgd_flags(gpgd) & _PAGE_PRESENT))
+ kill_guest(lg, "Bad address %#lx", vaddr);
+
+ gpte = lgread(lg, gpte_addr(lg, gpgd, vaddr), pte_t);
+ if (!(pte_flags(gpte) & _PAGE_PRESENT))
+ kill_guest(lg, "Bad address %#lx", vaddr);
+
+ return pte_pfn(gpte) * PAGE_SIZE | (vaddr & ~PAGE_MASK);
+}
+
/* We keep several page tables. This is a simple routine to find the page
* table (if any) corresponding to this top-level address the Guest has given
* us. */
@@ -376,7 +385,7 @@ static unsigned int find_pgdir(struct lguest *lg, unsigned long pgtable)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(lg->pgdirs); i++)
- if (lg->pgdirs[i].cr3 == pgtable)
+ if (lg->pgdirs[i].gpgdir == pgtable)
break;
return i;
}
@@ -385,7 +394,7 @@ static unsigned int find_pgdir(struct lguest *lg, unsigned long pgtable)
* allocate a new one (and so the kernel parts are not there), we set
* blank_pgdir. */
static unsigned int new_pgdir(struct lguest *lg,
- unsigned long cr3,
+ unsigned long gpgdir,
int *blank_pgdir)
{
unsigned int next;
@@ -395,7 +404,7 @@ static unsigned int new_pgdir(struct lguest *lg,
next = random32() % ARRAY_SIZE(lg->pgdirs);
/* If it's never been allocated at all before, try now. */
if (!lg->pgdirs[next].pgdir) {
- lg->pgdirs[next].pgdir = (spgd_t *)get_zeroed_page(GFP_KERNEL);
+ lg->pgdirs[next].pgdir = (pgd_t *)get_zeroed_page(GFP_KERNEL);
/* If the allocation fails, just keep using the one we have */
if (!lg->pgdirs[next].pgdir)
next = lg->pgdidx;
@@ -405,7 +414,7 @@ static unsigned int new_pgdir(struct lguest *lg,
*blank_pgdir = 1;
}
/* Record which Guest toplevel this shadows. */
- lg->pgdirs[next].cr3 = cr3;
+ lg->pgdirs[next].gpgdir = gpgdir;
/* Release all the non-kernel mappings. */
flush_user_mappings(lg, next);
@@ -472,26 +481,27 @@ void guest_pagetable_clear_all(struct lguest *lg)
* they set _PAGE_DIRTY then we can put a writable PTE entry in immediately.
*/
static void do_set_pte(struct lguest *lg, int idx,
- unsigned long vaddr, gpte_t gpte)
+ unsigned long vaddr, pte_t gpte)
{
/* Look up the matching shadow page directot entry. */
- spgd_t *spgd = spgd_addr(lg, idx, vaddr);
+ pgd_t *spgd = spgd_addr(lg, idx, vaddr);
/* If the top level isn't present, there's no entry to update. */
- if (spgd->flags & _PAGE_PRESENT) {
+ if (pgd_flags(*spgd) & _PAGE_PRESENT) {
/* Otherwise, we start by releasing the existing entry. */
- spte_t *spte = spte_addr(lg, *spgd, vaddr);
+ pte_t *spte = spte_addr(lg, *spgd, vaddr);
release_pte(*spte);
/* If they're setting this entry as dirty or accessed, we might
* as well put that entry they've given us in now. This shaves
* 10% off a copy-on-write micro-benchmark. */
- if (gpte.flags & (_PAGE_DIRTY | _PAGE_ACCESSED)) {
+ if (pte_flags(gpte) & (_PAGE_DIRTY | _PAGE_ACCESSED)) {
check_gpte(lg, gpte);
- *spte = gpte_to_spte(lg, gpte, gpte.flags&_PAGE_DIRTY);
+ *spte = gpte_to_spte(lg, gpte,
+ pte_flags(gpte) & _PAGE_DIRTY);
} else
/* Otherwise we can demand_page() it in later. */
- spte->raw.val = 0;
+ *spte = __pte(0);
}
}
@@ -506,18 +516,18 @@ static void do_set_pte(struct lguest *lg, int idx,
* The benefit is that when we have to track a new page table, we can copy keep
* all the kernel mappings. This speeds up context switch immensely. */
void guest_set_pte(struct lguest *lg,
- unsigned long cr3, unsigned long vaddr, gpte_t gpte)
+ unsigned long gpgdir, unsigned long vaddr, pte_t gpte)
{
/* Kernel mappings must be changed on all top levels. Slow, but
* doesn't happen often. */
- if (vaddr >= lg->page_offset) {
+ if (vaddr >= lg->kernel_address) {
unsigned int i;
for (i = 0; i < ARRAY_SIZE(lg->pgdirs); i++)
if (lg->pgdirs[i].pgdir)
do_set_pte(lg, i, vaddr, gpte);
} else {
/* Is this page table one we have a shadow for? */
- int pgdir = find_pgdir(lg, cr3);
+ int pgdir = find_pgdir(lg, gpgdir);
if (pgdir != ARRAY_SIZE(lg->pgdirs))
/* If so, do the update. */
do_set_pte(lg, pgdir, vaddr, gpte);
@@ -538,7 +548,7 @@ void guest_set_pte(struct lguest *lg,
*
* So with that in mind here's our code to to update a (top-level) PGD entry:
*/
-void guest_set_pmd(struct lguest *lg, unsigned long cr3, u32 idx)
+void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 idx)
{
int pgdir;
@@ -548,7 +558,7 @@ void guest_set_pmd(struct lguest *lg, unsigned long cr3, u32 idx)
return;
/* If they're talking about a page table we have a shadow for... */
- pgdir = find_pgdir(lg, cr3);
+ pgdir = find_pgdir(lg, gpgdir);
if (pgdir < ARRAY_SIZE(lg->pgdirs))
/* ... throw it away. */
release_pgd(lg, lg->pgdirs[pgdir].pgdir + idx);
@@ -560,21 +570,34 @@ void guest_set_pmd(struct lguest *lg, unsigned long cr3, u32 idx)
* its first page table is. We set some things up here: */
int init_guest_pagetable(struct lguest *lg, unsigned long pgtable)
{
- /* In flush_user_mappings() we loop from 0 to
- * "vaddr_to_pgd_index(lg->page_offset)". This assumes it won't hit
- * the Switcher mappings, so check that now. */
- if (vaddr_to_pgd_index(lg->page_offset) >= SWITCHER_PGD_INDEX)
- return -EINVAL;
/* We start on the first shadow page table, and give it a blank PGD
* page. */
lg->pgdidx = 0;
- lg->pgdirs[lg->pgdidx].cr3 = pgtable;
- lg->pgdirs[lg->pgdidx].pgdir = (spgd_t*)get_zeroed_page(GFP_KERNEL);
+ lg->pgdirs[lg->pgdidx].gpgdir = pgtable;
+ lg->pgdirs[lg->pgdidx].pgdir = (pgd_t*)get_zeroed_page(GFP_KERNEL);
if (!lg->pgdirs[lg->pgdidx].pgdir)
return -ENOMEM;
return 0;
}
+/* When the Guest calls LHCALL_LGUEST_INIT we do more setup. */
+void page_table_guest_data_init(struct lguest *lg)
+{
+ /* We get the kernel address: above this is all kernel memory. */
+ if (get_user(lg->kernel_address, &lg->lguest_data->kernel_address)
+ /* We tell the Guest that it can't use the top 4MB of virtual
+ * addresses used by the Switcher. */
+ || put_user(4U*1024*1024, &lg->lguest_data->reserve_mem)
+ || put_user(lg->pgdirs[lg->pgdidx].gpgdir,&lg->lguest_data->pgdir))
+ kill_guest(lg, "bad guest page %p", lg->lguest_data);
+
+ /* In flush_user_mappings() we loop from 0 to
+ * "pgd_index(lg->kernel_address)". This assumes it won't hit the
+ * Switcher mappings, so check that now. */
+ if (pgd_index(lg->kernel_address) >= SWITCHER_PGD_INDEX)
+ kill_guest(lg, "bad kernel address %#lx", lg->kernel_address);
+}
+
/* When a Guest dies, our cleanup is fairly simple. */
void free_guest_pagetable(struct lguest *lg)
{
@@ -594,14 +617,14 @@ void free_guest_pagetable(struct lguest *lg)
* for each CPU already set up, we just need to hook them in. */
void map_switcher_in_guest(struct lguest *lg, struct lguest_pages *pages)
{
- spte_t *switcher_pte_page = __get_cpu_var(switcher_pte_pages);
- spgd_t switcher_pgd;
- spte_t regs_pte;
+ pte_t *switcher_pte_page = __get_cpu_var(switcher_pte_pages);
+ pgd_t switcher_pgd;
+ pte_t regs_pte;
/* Make the last PGD entry for this Guest point to the Switcher's PTE
* page for this CPU (with appropriate flags). */
- switcher_pgd.pfn = __pa(switcher_pte_page) >> PAGE_SHIFT;
- switcher_pgd.flags = _PAGE_KERNEL;
+ switcher_pgd = __pgd(__pa(switcher_pte_page) | _PAGE_KERNEL);
+
lg->pgdirs[lg->pgdidx].pgdir[SWITCHER_PGD_INDEX] = switcher_pgd;
/* We also change the Switcher PTE page. When we're running the Guest,
@@ -611,10 +634,8 @@ void map_switcher_in_guest(struct lguest *lg, struct lguest_pages *pages)
* CPU's "struct lguest_pages": if we make sure the Guest's register
* page is already mapped there, we don't have to copy them out
* again. */
- regs_pte.pfn = __pa(lg->regs_page) >> PAGE_SHIFT;
- regs_pte.flags = _PAGE_KERNEL;
- switcher_pte_page[(unsigned long)pages/PAGE_SIZE%PTES_PER_PAGE]
- = regs_pte;
+ regs_pte = pfn_pte (__pa(lg->regs_page) >> PAGE_SHIFT, __pgprot(_PAGE_KERNEL));
+ switcher_pte_page[(unsigned long)pages/PAGE_SIZE%PTRS_PER_PTE] = regs_pte;
}
/*:*/
@@ -635,24 +656,25 @@ static __init void populate_switcher_pte_page(unsigned int cpu,
unsigned int pages)
{
unsigned int i;
- spte_t *pte = switcher_pte_page(cpu);
+ pte_t *pte = switcher_pte_page(cpu);
/* The first entries are easy: they map the Switcher code. */
for (i = 0; i < pages; i++) {
- pte[i].pfn = page_to_pfn(switcher_page[i]);
- pte[i].flags = _PAGE_PRESENT|_PAGE_ACCESSED;
+ pte[i] = mk_pte(switcher_page[i],
+ __pgprot(_PAGE_PRESENT|_PAGE_ACCESSED));
}
/* The only other thing we map is this CPU's pair of pages. */
i = pages + cpu*2;
/* First page (Guest registers) is writable from the Guest */
- pte[i].pfn = page_to_pfn(switcher_page[i]);
- pte[i].flags = _PAGE_PRESENT|_PAGE_ACCESSED|_PAGE_RW;
+ pte[i] = pfn_pte(page_to_pfn(switcher_page[i]),
+ __pgprot(_PAGE_PRESENT|_PAGE_ACCESSED|_PAGE_RW));
+
/* The second page contains the "struct lguest_ro_state", and is
* read-only. */
- pte[i+1].pfn = page_to_pfn(switcher_page[i+1]);
- pte[i+1].flags = _PAGE_PRESENT|_PAGE_ACCESSED;
+ pte[i+1] = pfn_pte(page_to_pfn(switcher_page[i+1]),
+ __pgprot(_PAGE_PRESENT|_PAGE_ACCESSED));
}
/*H:510 At boot or module load time, init_pagetables() allocates and populates
@@ -662,7 +684,7 @@ __init int init_pagetables(struct page **switcher_page, unsigned int pages)
unsigned int i;
for_each_possible_cpu(i) {
- switcher_pte_page(i) = (spte_t *)get_zeroed_page(GFP_KERNEL);
+ switcher_pte_page(i) = (pte_t *)get_zeroed_page(GFP_KERNEL);
if (!switcher_pte_page(i)) {
free_switcher_pte_pages();
return -ENOMEM;
diff --git a/drivers/lguest/segments.c b/drivers/lguest/segments.c
index 9b81119f46e..c2434ec99f7 100644
--- a/drivers/lguest/segments.c
+++ b/drivers/lguest/segments.c
@@ -73,14 +73,14 @@ static void fixup_gdt_table(struct lguest *lg, unsigned start, unsigned end)
/* Segment descriptors contain a privilege level: the Guest is
* sometimes careless and leaves this as 0, even though it's
* running at privilege level 1. If so, we fix it here. */
- if ((lg->gdt[i].b & 0x00006000) == 0)
- lg->gdt[i].b |= (GUEST_PL << 13);
+ if ((lg->arch.gdt[i].b & 0x00006000) == 0)
+ lg->arch.gdt[i].b |= (GUEST_PL << 13);
/* Each descriptor has an "accessed" bit. If we don't set it
* now, the CPU will try to set it when the Guest first loads
* that entry into a segment register. But the GDT isn't
* writable by the Guest, so bad things can happen. */
- lg->gdt[i].b |= 0x00000100;
+ lg->arch.gdt[i].b |= 0x00000100;
}
}
@@ -106,12 +106,12 @@ void setup_default_gdt_entries(struct lguest_ro_state *state)
void setup_guest_gdt(struct lguest *lg)
{
/* Start with full 0-4G segments... */
- lg->gdt[GDT_ENTRY_KERNEL_CS] = FULL_EXEC_SEGMENT;
- lg->gdt[GDT_ENTRY_KERNEL_DS] = FULL_SEGMENT;
+ lg->arch.gdt[GDT_ENTRY_KERNEL_CS] = FULL_EXEC_SEGMENT;
+ lg->arch.gdt[GDT_ENTRY_KERNEL_DS] = FULL_SEGMENT;
/* ...except the Guest is allowed to use them, so set the privilege
* level appropriately in the flags. */
- lg->gdt[GDT_ENTRY_KERNEL_CS].b |= (GUEST_PL << 13);
- lg->gdt[GDT_ENTRY_KERNEL_DS].b |= (GUEST_PL << 13);
+ lg->arch.gdt[GDT_ENTRY_KERNEL_CS].b |= (GUEST_PL << 13);
+ lg->arch.gdt[GDT_ENTRY_KERNEL_DS].b |= (GUEST_PL << 13);
}
/* Like the IDT, we never simply use the GDT the Guest gives us. We set up the
@@ -126,7 +126,7 @@ void copy_gdt_tls(const struct lguest *lg, struct desc_struct *gdt)
unsigned int i;
for (i = GDT_ENTRY_TLS_MIN; i <= GDT_ENTRY_TLS_MAX; i++)
- gdt[i] = lg->gdt[i];
+ gdt[i] = lg->arch.gdt[i];
}
/* This is the full version */
@@ -138,7 +138,7 @@ void copy_gdt(const struct lguest *lg, struct desc_struct *gdt)
* replaced. See ignored_gdt() above. */
for (i = 0; i < GDT_ENTRIES; i++)
if (!ignored_gdt(i))
- gdt[i] = lg->gdt[i];
+ gdt[i] = lg->arch.gdt[i];
}
/* This is where the Guest asks us to load a new GDT (LHCALL_LOAD_GDT). */
@@ -146,12 +146,12 @@ void load_guest_gdt(struct lguest *lg, unsigned long table, u32 num)
{
/* We assume the Guest has the same number of GDT entries as the
* Host, otherwise we'd have to dynamically allocate the Guest GDT. */
- if (num > ARRAY_SIZE(lg->gdt))
+ if (num > ARRAY_SIZE(lg->arch.gdt))
kill_guest(lg, "too many gdt entries %i", num);
/* We read the whole thing in, then fix it up. */
- lgread(lg, lg->gdt, table, num * sizeof(lg->gdt[0]));
- fixup_gdt_table(lg, 0, ARRAY_SIZE(lg->gdt));
+ __lgread(lg, lg->arch.gdt, table, num * sizeof(lg->arch.gdt[0]));
+ fixup_gdt_table(lg, 0, ARRAY_SIZE(lg->arch.gdt));
/* Mark that the GDT changed so the core knows it has to copy it again,
* even if the Guest is run on the same CPU. */
lg->changed |= CHANGED_GDT;
@@ -159,9 +159,9 @@ void load_guest_gdt(struct lguest *lg, unsigned long table, u32 num)
void guest_load_tls(struct lguest *lg, unsigned long gtls)
{
- struct desc_struct *tls = &lg->gdt[GDT_ENTRY_TLS_MIN];
+ struct desc_struct *tls = &lg->arch.gdt[GDT_ENTRY_TLS_MIN];
- lgread(lg, tls, gtls, sizeof(*tls)*GDT_ENTRY_TLS_ENTRIES);
+ __lgread(lg, tls, gtls, sizeof(*tls)*GDT_ENTRY_TLS_ENTRIES);
fixup_gdt_table(lg, GDT_ENTRY_TLS_MIN, GDT_ENTRY_TLS_MAX+1);
lg->changed |= CHANGED_GDT_TLS;
}
diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c
new file mode 100644
index 00000000000..9eed12d5a39
--- /dev/null
+++ b/drivers/lguest/x86/core.c
@@ -0,0 +1,577 @@
+/*
+ * Copyright (C) 2006, Rusty Russell <rusty@rustcorp.com.au> IBM Corporation.
+ * Copyright (C) 2007, Jes Sorensen <jes@sgi.com> SGI.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <linux/kernel.h>
+#include <linux/start_kernel.h>
+#include <linux/string.h>
+#include <linux/console.h>
+#include <linux/screen_info.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/cpu.h>
+#include <linux/lguest.h>
+#include <linux/lguest_launcher.h>
+#include <asm/paravirt.h>
+#include <asm/param.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/desc.h>
+#include <asm/setup.h>
+#include <asm/lguest.h>
+#include <asm/uaccess.h>
+#include <asm/i387.h>
+#include "../lg.h"
+
+static int cpu_had_pge;
+
+static struct {
+ unsigned long offset;
+ unsigned short segment;
+} lguest_entry;
+
+/* Offset from where switcher.S was compiled to where we've copied it */
+static unsigned long switcher_offset(void)
+{
+ return SWITCHER_ADDR - (unsigned long)start_switcher_text;
+}
+
+/* This cpu's struct lguest_pages. */
+static struct lguest_pages *lguest_pages(unsigned int cpu)
+{
+ return &(((struct lguest_pages *)
+ (SWITCHER_ADDR + SHARED_SWITCHER_PAGES*PAGE_SIZE))[cpu]);
+}
+
+static DEFINE_PER_CPU(struct lguest *, last_guest);
+
+/*S:010
+ * We are getting close to the Switcher.
+ *
+ * Remember that each CPU has two pages which are visible to the Guest when it
+ * runs on that CPU. This has to contain the state for that Guest: we copy the
+ * state in just before we run the Guest.
+ *
+ * Each Guest has "changed" flags which indicate what has changed in the Guest
+ * since it last ran. We saw this set in interrupts_and_traps.c and
+ * segments.c.
+ */
+static void copy_in_guest_info(struct lguest *lg, struct lguest_pages *pages)
+{
+ /* Copying all this data can be quite expensive. We usually run the
+ * same Guest we ran last time (and that Guest hasn't run anywhere else
+ * meanwhile). If that's not the case, we pretend everything in the
+ * Guest has changed. */
+ if (__get_cpu_var(last_guest) != lg || lg->last_pages != pages) {
+ __get_cpu_var(last_guest) = lg;
+ lg->last_pages = pages;
+ lg->changed = CHANGED_ALL;
+ }
+
+ /* These copies are pretty cheap, so we do them unconditionally: */
+ /* Save the current Host top-level page directory. */
+ pages->state.host_cr3 = __pa(current->mm->pgd);
+ /* Set up the Guest's page tables to see this CPU's pages (and no
+ * other CPU's pages). */
+ map_switcher_in_guest(lg, pages);
+ /* Set up the two "TSS" members which tell the CPU what stack to use
+ * for traps which do directly into the Guest (ie. traps at privilege
+ * level 1). */
+ pages->state.guest_tss.esp1 = lg->esp1;
+ pages->state.guest_tss.ss1 = lg->ss1;
+
+ /* Copy direct-to-Guest trap entries. */
+ if (lg->changed & CHANGED_IDT)
+ copy_traps(lg, pages->state.guest_idt, default_idt_entries);
+
+ /* Copy all GDT entries which the Guest can change. */
+ if (lg->changed & CHANGED_GDT)
+ copy_gdt(lg, pages->state.guest_gdt);
+ /* If only the TLS entries have changed, copy them. */
+ else if (lg->changed & CHANGED_GDT_TLS)
+ copy_gdt_tls(lg, pages->state.guest_gdt);
+
+ /* Mark the Guest as unchanged for next time. */
+ lg->changed = 0;
+}
+
+/* Finally: the code to actually call into the Switcher to run the Guest. */
+static void run_guest_once(struct lguest *lg, struct lguest_pages *pages)
+{
+ /* This is a dummy value we need for GCC's sake. */
+ unsigned int clobber;
+
+ /* Copy the guest-specific information into this CPU's "struct
+ * lguest_pages". */
+ copy_in_guest_info(lg, pages);
+
+ /* Set the trap number to 256 (impossible value). If we fault while
+ * switching to the Guest (bad segment registers or bug), this will
+ * cause us to abort the Guest. */
+ lg->regs->trapnum = 256;
+
+ /* Now: we push the "eflags" register on the stack, then do an "lcall".
+ * This is how we change from using the kernel code segment to using
+ * the dedicated lguest code segment, as well as jumping into the
+ * Switcher.
+ *
+ * The lcall also pushes the old code segment (KERNEL_CS) onto the
+ * stack, then the address of this call. This stack layout happens to
+ * exactly match the stack of an interrupt... */
+ asm volatile("pushf; lcall *lguest_entry"
+ /* This is how we tell GCC that %eax ("a") and %ebx ("b")
+ * are changed by this routine. The "=" means output. */
+ : "=a"(clobber), "=b"(clobber)
+ /* %eax contains the pages pointer. ("0" refers to the
+ * 0-th argument above, ie "a"). %ebx contains the
+ * physical address of the Guest's top-level page
+ * directory. */
+ : "0"(pages), "1"(__pa(lg->pgdirs[lg->pgdidx].pgdir))
+ /* We tell gcc that all these registers could change,
+ * which means we don't have to save and restore them in
+ * the Switcher. */
+ : "memory", "%edx", "%ecx", "%edi", "%esi");
+}
+/*:*/
+
+/*H:040 This is the i386-specific code to setup and run the Guest. Interrupts
+ * are disabled: we own the CPU. */
+void lguest_arch_run_guest(struct lguest *lg)
+{
+ /* Remember the awfully-named TS bit? If the Guest has asked
+ * to set it we set it now, so we can trap and pass that trap
+ * to the Guest if it uses the FPU. */
+ if (lg->ts)
+ lguest_set_ts();
+
+ /* SYSENTER is an optimized way of doing system calls. We
+ * can't allow it because it always jumps to privilege level 0.
+ * A normal Guest won't try it because we don't advertise it in
+ * CPUID, but a malicious Guest (or malicious Guest userspace
+ * program) could, so we tell the CPU to disable it before
+ * running the Guest. */
+ if (boot_cpu_has(X86_FEATURE_SEP))
+ wrmsr(MSR_IA32_SYSENTER_CS, 0, 0);
+
+ /* Now we actually run the Guest. It will pop back out when
+ * something interesting happens, and we can examine its
+ * registers to see what it was doing. */
+ run_guest_once(lg, lguest_pages(raw_smp_processor_id()));
+
+ /* The "regs" pointer contains two extra entries which are not
+ * really registers: a trap number which says what interrupt or
+ * trap made the switcher code come back, and an error code
+ * which some traps set. */
+
+ /* If the Guest page faulted, then the cr2 register will tell
+ * us the bad virtual address. We have to grab this now,
+ * because once we re-enable interrupts an interrupt could
+ * fault and thus overwrite cr2, or we could even move off to a
+ * different CPU. */
+ if (lg->regs->trapnum == 14)
+ lg->arch.last_pagefault = read_cr2();
+ /* Similarly, if we took a trap because the Guest used the FPU,
+ * we have to restore the FPU it expects to see. */
+ else if (lg->regs->trapnum == 7)
+ math_state_restore();
+
+ /* Restore SYSENTER if it's supposed to be on. */
+ if (boot_cpu_has(X86_FEATURE_SEP))
+ wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
+}
+
+/*H:130 Our Guest is usually so well behaved; it never tries to do things it
+ * isn't allowed to. Unfortunately, Linux's paravirtual infrastructure isn't
+ * quite complete, because it doesn't contain replacements for the Intel I/O
+ * instructions. As a result, the Guest sometimes fumbles across one during
+ * the boot process as it probes for various things which are usually attached
+ * to a PC.
+ *
+ * When the Guest uses one of these instructions, we get trap #13 (General
+ * Protection Fault) and come here. We see if it's one of those troublesome
+ * instructions and skip over it. We return true if we did. */
+static int emulate_insn(struct lguest *lg)
+{
+ u8 insn;
+ unsigned int insnlen = 0, in = 0, shift = 0;
+ /* The eip contains the *virtual* address of the Guest's instruction:
+ * guest_pa just subtracts the Guest's page_offset. */
+ unsigned long physaddr = guest_pa(lg, lg->regs->eip);
+
+ /* This must be the Guest kernel trying to do something, not userspace!
+ * The bottom two bits of the CS segment register are the privilege
+ * level. */
+ if ((lg->regs->cs & 3) != GUEST_PL)
+ return 0;
+
+ /* Decoding x86 instructions is icky. */
+ insn = lgread(lg, physaddr, u8);
+
+ /* 0x66 is an "operand prefix". It means it's using the upper 16 bits
+ of the eax register. */
+ if (insn == 0x66) {
+ shift = 16;
+ /* The instruction is 1 byte so far, read the next byte. */
+ insnlen = 1;
+ insn = lgread(lg, physaddr + insnlen, u8);
+ }
+
+ /* We can ignore the lower bit for the moment and decode the 4 opcodes
+ * we need to emulate. */
+ switch (insn & 0xFE) {
+ case 0xE4: /* in <next byte>,%al */
+ insnlen += 2;
+ in = 1;
+ break;
+ case 0xEC: /* in (%dx),%al */
+ insnlen += 1;
+ in = 1;
+ break;
+ case 0xE6: /* out %al,<next byte> */
+ insnlen += 2;
+ break;
+ case 0xEE: /* out %al,(%dx) */
+ insnlen += 1;
+ break;
+ default:
+ /* OK, we don't know what this is, can't emulate. */
+ return 0;
+ }
+
+ /* If it was an "IN" instruction, they expect the result to be read
+ * into %eax, so we change %eax. We always return all-ones, which
+ * traditionally means "there's nothing there". */
+ if (in) {
+ /* Lower bit tells is whether it's a 16 or 32 bit access */
+ if (insn & 0x1)
+ lg->regs->eax = 0xFFFFFFFF;
+ else
+ lg->regs->eax |= (0xFFFF << shift);
+ }
+ /* Finally, we've "done" the instruction, so move past it. */
+ lg->regs->eip += insnlen;
+ /* Success! */
+ return 1;
+}
+
+/*H:050 Once we've re-enabled interrupts, we look at why the Guest exited. */
+void lguest_arch_handle_trap(struct lguest *lg)
+{
+ switch (lg->regs->trapnum) {
+ case 13: /* We've intercepted a GPF. */
+ /* Check if this was one of those annoying IN or OUT
+ * instructions which we need to emulate. If so, we
+ * just go back into the Guest after we've done it. */
+ if (lg->regs->errcode == 0) {
+ if (emulate_insn(lg))
+ return;
+ }
+ break;
+ case 14: /* We've intercepted a page fault. */
+ /* The Guest accessed a virtual address that wasn't
+ * mapped. This happens a lot: we don't actually set
+ * up most of the page tables for the Guest at all when
+ * we start: as it runs it asks for more and more, and
+ * we set them up as required. In this case, we don't
+ * even tell the Guest that the fault happened.
+ *
+ * The errcode tells whether this was a read or a
+ * write, and whether kernel or userspace code. */
+ if (demand_page(lg, lg->arch.last_pagefault, lg->regs->errcode))
+ return;
+
+ /* OK, it's really not there (or not OK): the Guest
+ * needs to know. We write out the cr2 value so it
+ * knows where the fault occurred.
+ *
+ * Note that if the Guest were really messed up, this
+ * could happen before it's done the INITIALIZE
+ * hypercall, so lg->lguest_data will be NULL */
+ if (lg->lguest_data &&
+ put_user(lg->arch.last_pagefault, &lg->lguest_data->cr2))
+ kill_guest(lg, "Writing cr2");
+ break;
+ case 7: /* We've intercepted a Device Not Available fault. */
+ /* If the Guest doesn't want to know, we already
+ * restored the Floating Point Unit, so we just
+ * continue without telling it. */
+ if (!lg->ts)
+ return;
+ break;
+ case 32 ... 255:
+ /* These values mean a real interrupt occurred, in which case
+ * the Host handler has already been run. We just do a
+ * friendly check if another process should now be run, then
+ * return to run the Guest again */
+ cond_resched();
+ return;
+ case LGUEST_TRAP_ENTRY:
+ /* Our 'struct hcall_args' maps directly over our regs: we set
+ * up the pointer now to indicate a hypercall is pending. */
+ lg->hcall = (struct hcall_args *)lg->regs;
+ return;
+ }
+
+ /* We didn't handle the trap, so it needs to go to the Guest. */
+ if (!deliver_trap(lg, lg->regs->trapnum))
+ /* If the Guest doesn't have a handler (either it hasn't
+ * registered any yet, or it's one of the faults we don't let
+ * it handle), it dies with a cryptic error message. */
+ kill_guest(lg, "unhandled trap %li at %#lx (%#lx)",
+ lg->regs->trapnum, lg->regs->eip,
+ lg->regs->trapnum == 14 ? lg->arch.last_pagefault
+ : lg->regs->errcode);
+}
+
+/* Now we can look at each of the routines this calls, in increasing order of
+ * complexity: do_hypercalls(), emulate_insn(), maybe_do_interrupt(),
+ * deliver_trap() and demand_page(). After all those, we'll be ready to
+ * examine the Switcher, and our philosophical understanding of the Host/Guest
+ * duality will be complete. :*/
+static void adjust_pge(void *on)
+{
+ if (on)
+ write_cr4(read_cr4() | X86_CR4_PGE);
+ else
+ write_cr4(read_cr4() & ~X86_CR4_PGE);
+}
+
+/*H:020 Now the Switcher is mapped and every thing else is ready, we need to do
+ * some more i386-specific initialization. */
+void __init lguest_arch_host_init(void)
+{
+ int i;
+
+ /* Most of the i386/switcher.S doesn't care that it's been moved; on
+ * Intel, jumps are relative, and it doesn't access any references to
+ * external code or data.
+ *
+ * The only exception is the interrupt handlers in switcher.S: their
+ * addresses are placed in a table (default_idt_entries), so we need to
+ * update the table with the new addresses. switcher_offset() is a
+ * convenience function which returns the distance between the builtin
+ * switcher code and the high-mapped copy we just made. */
+ for (i = 0; i < IDT_ENTRIES; i++)
+ default_idt_entries[i] += switcher_offset();
+
+ /*
+ * Set up the Switcher's per-cpu areas.
+ *
+ * Each CPU gets two pages of its own within the high-mapped region
+ * (aka. "struct lguest_pages"). Much of this can be initialized now,
+ * but some depends on what Guest we are running (which is set up in
+ * copy_in_guest_info()).
+ */
+ for_each_possible_cpu(i) {
+ /* lguest_pages() returns this CPU's two pages. */
+ struct lguest_pages *pages = lguest_pages(i);
+ /* This is a convenience pointer to make the code fit one
+ * statement to a line. */
+ struct lguest_ro_state *state = &pages->state;
+
+ /* The Global Descriptor Table: the Host has a different one
+ * for each CPU. We keep a descriptor for the GDT which says
+ * where it is and how big it is (the size is actually the last
+ * byte, not the size, hence the "-1"). */
+ state->host_gdt_desc.size = GDT_SIZE-1;
+ state->host_gdt_desc.address = (long)get_cpu_gdt_table(i);
+
+ /* All CPUs on the Host use the same Interrupt Descriptor
+ * Table, so we just use store_idt(), which gets this CPU's IDT
+ * descriptor. */
+ store_idt(&state->host_idt_desc);
+
+ /* The descriptors for the Guest's GDT and IDT can be filled
+ * out now, too. We copy the GDT & IDT into ->guest_gdt and
+ * ->guest_idt before actually running the Guest. */
+ state->guest_idt_desc.size = sizeof(state->guest_idt)-1;
+ state->guest_idt_desc.address = (long)&state->guest_idt;
+ state->guest_gdt_desc.size = sizeof(state->guest_gdt)-1;
+ state->guest_gdt_desc.address = (long)&state->guest_gdt;
+
+ /* We know where we want the stack to be when the Guest enters
+ * the switcher: in pages->regs. The stack grows upwards, so
+ * we start it at the end of that structure. */
+ state->guest_tss.esp0 = (long)(&pages->regs + 1);
+ /* And this is the GDT entry to use for the stack: we keep a
+ * couple of special LGUEST entries. */
+ state->guest_tss.ss0 = LGUEST_DS;
+
+ /* x86 can have a finegrained bitmap which indicates what I/O
+ * ports the process can use. We set it to the end of our
+ * structure, meaning "none". */
+ state->guest_tss.io_bitmap_base = sizeof(state->guest_tss);
+
+ /* Some GDT entries are the same across all Guests, so we can
+ * set them up now. */
+ setup_default_gdt_entries(state);
+ /* Most IDT entries are the same for all Guests, too.*/
+ setup_default_idt_entries(state, default_idt_entries);
+
+ /* The Host needs to be able to use the LGUEST segments on this
+ * CPU, too, so put them in the Host GDT. */
+ get_cpu_gdt_table(i)[GDT_ENTRY_LGUEST_CS] = FULL_EXEC_SEGMENT;
+ get_cpu_gdt_table(i)[GDT_ENTRY_LGUEST_DS] = FULL_SEGMENT;
+ }
+
+ /* In the Switcher, we want the %cs segment register to use the
+ * LGUEST_CS GDT entry: we've put that in the Host and Guest GDTs, so
+ * it will be undisturbed when we switch. To change %cs and jump we
+ * need this structure to feed to Intel's "lcall" instruction. */
+ lguest_entry.offset = (long)switch_to_guest + switcher_offset();
+ lguest_entry.segment = LGUEST_CS;
+
+ /* Finally, we need to turn off "Page Global Enable". PGE is an
+ * optimization where page table entries are specially marked to show
+ * they never change. The Host kernel marks all the kernel pages this
+ * way because it's always present, even when userspace is running.
+ *
+ * Lguest breaks this: unbeknownst to the rest of the Host kernel, we
+ * switch to the Guest kernel. If you don't disable this on all CPUs,
+ * you'll get really weird bugs that you'll chase for two days.
+ *
+ * I used to turn PGE off every time we switched to the Guest and back
+ * on when we return, but that slowed the Switcher down noticibly. */
+
+ /* We don't need the complexity of CPUs coming and going while we're
+ * doing this. */
+ lock_cpu_hotplug();
+ if (cpu_has_pge) { /* We have a broader idea of "global". */
+ /* Remember that this was originally set (for cleanup). */
+ cpu_had_pge = 1;
+ /* adjust_pge is a helper function which sets or unsets the PGE
+ * bit on its CPU, depending on the argument (0 == unset). */
+ on_each_cpu(adjust_pge, (void *)0, 0, 1);
+ /* Turn off the feature in the global feature set. */
+ clear_bit(X86_FEATURE_PGE, boot_cpu_data.x86_capability);
+ }
+ unlock_cpu_hotplug();
+};
+/*:*/
+
+void __exit lguest_arch_host_fini(void)
+{
+ /* If we had PGE before we started, turn it back on now. */
+ lock_cpu_hotplug();
+ if (cpu_had_pge) {
+ set_bit(X86_FEATURE_PGE, boot_cpu_data.x86_capability);
+ /* adjust_pge's argument "1" means set PGE. */
+ on_each_cpu(adjust_pge, (void *)1, 0, 1);
+ }
+ unlock_cpu_hotplug();
+}
+
+
+/*H:122 The i386-specific hypercalls simply farm out to the right functions. */
+int lguest_arch_do_hcall(struct lguest *lg, struct hcall_args *args)
+{
+ switch (args->arg0) {
+ case LHCALL_LOAD_GDT:
+ load_guest_gdt(lg, args->arg1, args->arg2);
+ break;
+ case LHCALL_LOAD_IDT_ENTRY:
+ load_guest_idt_entry(lg, args->arg1, args->arg2, args->arg3);
+ break;
+ case LHCALL_LOAD_TLS:
+ guest_load_tls(lg, args->arg1);
+ break;
+ default:
+ /* Bad Guest. Bad! */
+ return -EIO;
+ }
+ return 0;
+}
+
+/*H:126 i386-specific hypercall initialization: */
+int lguest_arch_init_hypercalls(struct lguest *lg)
+{
+ u32 tsc_speed;
+
+ /* The pointer to the Guest's "struct lguest_data" is the only
+ * argument. We check that address now. */
+ if (!lguest_address_ok(lg, lg->hcall->arg1, sizeof(*lg->lguest_data)))
+ return -EFAULT;
+
+ /* Having checked it, we simply set lg->lguest_data to point straight
+ * into the Launcher's memory at the right place and then use
+ * copy_to_user/from_user from now on, instead of lgread/write. I put
+ * this in to show that I'm not immune to writing stupid
+ * optimizations. */
+ lg->lguest_data = lg->mem_base + lg->hcall->arg1;
+
+ /* We insist that the Time Stamp Counter exist and doesn't change with
+ * cpu frequency. Some devious chip manufacturers decided that TSC
+ * changes could be handled in software. I decided that time going
+ * backwards might be good for benchmarks, but it's bad for users.
+ *
+ * We also insist that the TSC be stable: the kernel detects unreliable
+ * TSCs for its own purposes, and we use that here. */
+ if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) && !check_tsc_unstable())
+ tsc_speed = tsc_khz;
+ else
+ tsc_speed = 0;
+ if (put_user(tsc_speed, &lg->lguest_data->tsc_khz))
+ return -EFAULT;
+
+ /* The interrupt code might not like the system call vector. */
+ if (!check_syscall_vector(lg))
+ kill_guest(lg, "bad syscall vector");
+
+ return 0;
+}
+/* Now we've examined the hypercall code; our Guest can make requests. There
+ * is one other way we can do things for the Guest, as we see in
+ * emulate_insn(). :*/
+
+/*L:030 lguest_arch_setup_regs()
+ *
+ * Most of the Guest's registers are left alone: we used get_zeroed_page() to
+ * allocate the structure, so they will be 0. */
+void lguest_arch_setup_regs(struct lguest *lg, unsigned long start)
+{
+ struct lguest_regs *regs = lg->regs;
+
+ /* There are four "segment" registers which the Guest needs to boot:
+ * The "code segment" register (cs) refers to the kernel code segment
+ * __KERNEL_CS, and the "data", "extra" and "stack" segment registers
+ * refer to the kernel data segment __KERNEL_DS.
+ *
+ * The privilege level is packed into the lower bits. The Guest runs
+ * at privilege level 1 (GUEST_PL).*/
+ regs->ds = regs->es = regs->ss = __KERNEL_DS|GUEST_PL;
+ regs->cs = __KERNEL_CS|GUEST_PL;
+
+ /* The "eflags" register contains miscellaneous flags. Bit 1 (0x002)
+ * is supposed to always be "1". Bit 9 (0x200) controls whether
+ * interrupts are enabled. We always leave interrupts enabled while
+ * running the Guest. */
+ regs->eflags = 0x202;
+
+ /* The "Extended Instruction Pointer" register says where the Guest is
+ * running. */
+ regs->eip = start;
+
+ /* %esi points to our boot information, at physical address 0, so don't
+ * touch it. */
+ /* There are a couple of GDT entries the Guest expects when first
+ * booting. */
+
+ setup_guest_gdt(lg);
+}
diff --git a/drivers/lguest/switcher.S b/drivers/lguest/x86/switcher_32.S
index 7c9c230cc84..1010b90b11f 100644
--- a/drivers/lguest/switcher.S
+++ b/drivers/lguest/x86/switcher_32.S
@@ -48,7 +48,8 @@
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/page.h>
-#include "lg.h"
+#include <asm/segment.h>
+#include <asm/lguest.h>
// We mark the start of the code to copy
// It's placed in .text tho it's never run here
@@ -132,6 +133,7 @@ ENTRY(switch_to_guest)
// The Guest's register page has been mapped
// Writable onto our %esp (stack) --
// We can simply pop off all Guest regs.
+ popl %eax
popl %ebx
popl %ecx
popl %edx
@@ -139,7 +141,6 @@ ENTRY(switch_to_guest)
popl %edi
popl %ebp
popl %gs
- popl %eax
popl %fs
popl %ds
popl %es
@@ -167,7 +168,6 @@ ENTRY(switch_to_guest)
pushl %es; \
pushl %ds; \
pushl %fs; \
- pushl %eax; \
pushl %gs; \
pushl %ebp; \
pushl %edi; \
@@ -175,6 +175,7 @@ ENTRY(switch_to_guest)
pushl %edx; \
pushl %ecx; \
pushl %ebx; \
+ pushl %eax; \
/* Our stack and our code are using segments \
* Set in the TSS and IDT \
* Yet if we were to touch data we'd use \
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index ce34b539bf3..2538816817a 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -3100,4 +3100,10 @@ config NETPOLL_TRAP
config NET_POLL_CONTROLLER
def_bool NETPOLL
+config VIRTIO_NET
+ tristate "Virtio network driver (EXPERIMENTAL)"
+ depends on EXPERIMENTAL && VIRTIO
+ ---help---
+ This is the virtual network driver for lguest. Say Y or M.
+
endif # NETDEVICES
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index 22f78cbd126..593262065c9 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -183,7 +183,6 @@ obj-$(CONFIG_ZORRO8390) += zorro8390.o
obj-$(CONFIG_HPLANCE) += hplance.o 7990.o
obj-$(CONFIG_MVME147_NET) += mvme147.o 7990.o
obj-$(CONFIG_EQUALIZER) += eql.o
-obj-$(CONFIG_LGUEST_NET) += lguest_net.o
obj-$(CONFIG_MIPS_JAZZ_SONIC) += jazzsonic.o
obj-$(CONFIG_MIPS_AU1X00_ENET) += au1000_eth.o
obj-$(CONFIG_MIPS_SIM_NET) += mipsnet.o
@@ -243,3 +242,4 @@ obj-$(CONFIG_FS_ENET) += fs_enet/
obj-$(CONFIG_NETXEN_NIC) += netxen/
obj-$(CONFIG_NIU) += niu.o
+obj-$(CONFIG_VIRTIO_NET) += virtio_net.o
diff --git a/drivers/net/lguest_net.c b/drivers/net/lguest_net.c
deleted file mode 100644
index abce2ee8430..00000000000
--- a/drivers/net/lguest_net.c
+++ /dev/null
@@ -1,555 +0,0 @@
-/*D:500
- * The Guest network driver.
- *
- * This is very simple a virtual network driver, and our last Guest driver.
- * The only trick is that it can talk directly to multiple other recipients
- * (ie. other Guests on the same network). It can also be used with only the
- * Host on the network.
- :*/
-
-/* Copyright 2006 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-//#define DEBUG
-#include <linux/netdevice.h>
-#include <linux/etherdevice.h>
-#include <linux/module.h>
-#include <linux/mm_types.h>
-#include <linux/io.h>
-#include <linux/lguest_bus.h>
-
-#define SHARED_SIZE PAGE_SIZE
-#define MAX_LANS 4
-#define NUM_SKBS 8
-
-/*M:011 Network code master Jeff Garzik points out numerous shortcomings in
- * this driver if it aspires to greatness.
- *
- * Firstly, it doesn't use "NAPI": the networking's New API, and is poorer for
- * it. As he says "NAPI means system-wide load leveling, across multiple
- * network interfaces. Lack of NAPI can mean competition at higher loads."
- *
- * He also points out that we don't implement set_mac_address, so users cannot
- * change the devices hardware address. When I asked why one would want to:
- * "Bonding, and situations where you /do/ want the MAC address to "leak" out
- * of the host onto the wider net."
- *
- * Finally, he would like module unloading: "It is not unrealistic to think of
- * [un|re|]loading the net support module in an lguest guest. And, adding
- * module support makes the programmer more responsible, because they now have
- * to learn to clean up after themselves. Any driver that cannot clean up
- * after itself is an incomplete driver in my book."
- :*/
-
-/*D:530 The "struct lguestnet_info" contains all the information we need to
- * know about the network device. */
-struct lguestnet_info
-{
- /* The mapped device page(s) (an array of "struct lguest_net"). */
- struct lguest_net *peer;
- /* The physical address of the device page(s) */
- unsigned long peer_phys;
- /* The size of the device page(s). */
- unsigned long mapsize;
-
- /* The lguest_device I come from */
- struct lguest_device *lgdev;
-
- /* My peerid (ie. my slot in the array). */
- unsigned int me;
-
- /* Receive queue: the network packets waiting to be filled. */
- struct sk_buff *skb[NUM_SKBS];
- struct lguest_dma dma[NUM_SKBS];
-};
-/*:*/
-
-/* How many bytes left in this page. */
-static unsigned int rest_of_page(void *data)
-{
- return PAGE_SIZE - ((unsigned long)data % PAGE_SIZE);
-}
-
-/*D:570 Each peer (ie. Guest or Host) on the network binds their receive
- * buffers to a different key: we simply use the physical address of the
- * device's memory page plus the peer number. The Host insists that all keys
- * be a multiple of 4, so we multiply the peer number by 4. */
-static unsigned long peer_key(struct lguestnet_info *info, unsigned peernum)
-{
- return info->peer_phys + 4 * peernum;
-}
-
-/* This is the routine which sets up a "struct lguest_dma" to point to a
- * network packet, similar to req_to_dma() in lguest_blk.c. The structure of a
- * "struct sk_buff" has grown complex over the years: it consists of a "head"
- * linear section pointed to by "skb->data", and possibly an array of
- * "fragments" in the case of a non-linear packet.
- *
- * Our receive buffers don't use fragments at all but outgoing skbs might, so
- * we handle it. */
-static void skb_to_dma(const struct sk_buff *skb, unsigned int headlen,
- struct lguest_dma *dma)
-{
- unsigned int i, seg;
-
- /* First, we put the linear region into the "struct lguest_dma". Each
- * entry can't go over a page boundary, so even though all our packets
- * are 1514 bytes or less, we might need to use two entries here: */
- for (i = seg = 0; i < headlen; seg++, i += rest_of_page(skb->data+i)) {
- dma->addr[seg] = virt_to_phys(skb->data + i);
- dma->len[seg] = min((unsigned)(headlen - i),
- rest_of_page(skb->data + i));
- }
-
- /* Now we handle the fragments: at least they're guaranteed not to go
- * over a page. skb_shinfo(skb) returns a pointer to the structure
- * which tells us about the number of fragments and the fragment
- * array. */
- for (i = 0; i < skb_shinfo(skb)->nr_frags; i++, seg++) {
- const skb_frag_t *f = &skb_shinfo(skb)->frags[i];
- /* Should not happen with MTU less than 64k - 2 * PAGE_SIZE. */
- if (seg == LGUEST_MAX_DMA_SECTIONS) {
- /* We will end up sending a truncated packet should
- * this ever happen. Plus, a cool log message! */
- printk("Woah dude! Megapacket!\n");
- break;
- }
- dma->addr[seg] = page_to_phys(f->page) + f->page_offset;
- dma->len[seg] = f->size;
- }
-
- /* If after all that we didn't use the entire "struct lguest_dma"
- * array, we terminate it with a 0 length. */
- if (seg < LGUEST_MAX_DMA_SECTIONS)
- dma->len[seg] = 0;
-}
-
-/*
- * Packet transmission.
- *
- * Our packet transmission is a little unusual. A real network card would just
- * send out the packet and leave the receivers to decide if they're interested.
- * Instead, we look through the network device memory page and see if any of
- * the ethernet addresses match the packet destination, and if so we send it to
- * that Guest.
- *
- * This is made a little more complicated in two cases. The first case is
- * broadcast packets: for that we send the packet to all Guests on the network,
- * one at a time. The second case is "promiscuous" mode, where a Guest wants
- * to see all the packets on the network. We need a way for the Guest to tell
- * us it wants to see all packets, so it sets the "multicast" bit on its
- * published MAC address, which is never valid in a real ethernet address.
- */
-#define PROMISC_BIT 0x01
-
-/* This is the callback which is summoned whenever the network device's
- * multicast or promiscuous state changes. If the card is in promiscuous mode,
- * we advertise that in our ethernet address in the device's memory. We do the
- * same if Linux wants any or all multicast traffic. */
-static void lguestnet_set_multicast(struct net_device *dev)
-{
- struct lguestnet_info *info = netdev_priv(dev);
-
- if ((dev->flags & (IFF_PROMISC|IFF_ALLMULTI)) || dev->mc_count)
- info->peer[info->me].mac[0] |= PROMISC_BIT;
- else
- info->peer[info->me].mac[0] &= ~PROMISC_BIT;
-}
-
-/* A simple test function to see if a peer wants to see all packets.*/
-static int promisc(struct lguestnet_info *info, unsigned int peer)
-{
- return info->peer[peer].mac[0] & PROMISC_BIT;
-}
-
-/* Another simple function to see if a peer's advertised ethernet address
- * matches a packet's destination ethernet address. */
-static int mac_eq(const unsigned char mac[ETH_ALEN],
- struct lguestnet_info *info, unsigned int peer)
-{
- /* Ignore multicast bit, which peer turns on to mean promisc. */
- if ((info->peer[peer].mac[0] & (~PROMISC_BIT)) != mac[0])
- return 0;
- return memcmp(mac+1, info->peer[peer].mac+1, ETH_ALEN-1) == 0;
-}
-
-/* This is the function which actually sends a packet once we've decided a
- * peer wants it: */
-static void transfer_packet(struct net_device *dev,
- struct sk_buff *skb,
- unsigned int peernum)
-{
- struct lguestnet_info *info = netdev_priv(dev);
- struct lguest_dma dma;
-
- /* We use our handy "struct lguest_dma" packing function to prepare
- * the skb for sending. */
- skb_to_dma(skb, skb_headlen(skb), &dma);
- pr_debug("xfer length %04x (%u)\n", htons(skb->len), skb->len);
-
- /* This is the actual send call which copies the packet. */
- lguest_send_dma(peer_key(info, peernum), &dma);
-
- /* Check that the entire packet was transmitted. If not, it could mean
- * that the other Guest registered a short receive buffer, but this
- * driver should never do that. More likely, the peer is dead. */
- if (dma.used_len != skb->len) {
- dev->stats.tx_carrier_errors++;
- pr_debug("Bad xfer to peer %i: %i of %i (dma %p/%i)\n",
- peernum, dma.used_len, skb->len,
- (void *)dma.addr[0], dma.len[0]);
- } else {
- /* On success we update the stats. */
- dev->stats.tx_bytes += skb->len;
- dev->stats.tx_packets++;
- }
-}
-
-/* Another helper function to tell is if a slot in the device memory is unused.
- * Since we always set the Local Assignment bit in the ethernet address, the
- * first byte can never be 0. */
-static int unused_peer(const struct lguest_net peer[], unsigned int num)
-{
- return peer[num].mac[0] == 0;
-}
-
-/* Finally, here is the routine which handles an outgoing packet. It's called
- * "start_xmit" for traditional reasons. */
-static int lguestnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
-{
- unsigned int i;
- int broadcast;
- struct lguestnet_info *info = netdev_priv(dev);
- /* Extract the destination ethernet address from the packet. */
- const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
- DECLARE_MAC_BUF(mac);
-
- pr_debug("%s: xmit %s\n", dev->name, print_mac(mac, dest));
-
- /* If it's a multicast packet, we broadcast to everyone. That's not
- * very efficient, but there are very few applications which actually
- * use multicast, which is a shame really.
- *
- * As etherdevice.h points out: "By definition the broadcast address is
- * also a multicast address." So we don't have to test for broadcast
- * packets separately. */
- broadcast = is_multicast_ether_addr(dest);
-
- /* Look through all the published ethernet addresses to see if we
- * should send this packet. */
- for (i = 0; i < info->mapsize/sizeof(struct lguest_net); i++) {
- /* We don't send to ourselves (we actually can't SEND_DMA to
- * ourselves anyway), and don't send to unused slots.*/
- if (i == info->me || unused_peer(info->peer, i))
- continue;
-
- /* If it's broadcast we send it. If they want every packet we
- * send it. If the destination matches their address we send
- * it. Otherwise we go to the next peer. */
- if (!broadcast && !promisc(info, i) && !mac_eq(dest, info, i))
- continue;
-
- pr_debug("lguestnet %s: sending from %i to %i\n",
- dev->name, info->me, i);
- /* Our routine which actually does the transfer. */
- transfer_packet(dev, skb, i);
- }
-
- /* An xmit routine is expected to dispose of the packet, so we do. */
- dev_kfree_skb(skb);
-
- /* As per kernel convention, 0 means success. This is why I love
- * networking: even if we never sent to anyone, that's still
- * success! */
- return 0;
-}
-
-/*D:560
- * Packet receiving.
- *
- * First, here's a helper routine which fills one of our array of receive
- * buffers: */
-static int fill_slot(struct net_device *dev, unsigned int slot)
-{
- struct lguestnet_info *info = netdev_priv(dev);
-
- /* We can receive ETH_DATA_LEN (1500) byte packets, plus a standard
- * ethernet header of ETH_HLEN (14) bytes. */
- info->skb[slot] = netdev_alloc_skb(dev, ETH_HLEN + ETH_DATA_LEN);
- if (!info->skb[slot]) {
- printk("%s: could not fill slot %i\n", dev->name, slot);
- return -ENOMEM;
- }
-
- /* skb_to_dma() is a helper which sets up the "struct lguest_dma" to
- * point to the data in the skb: we also use it for sending out a
- * packet. */
- skb_to_dma(info->skb[slot], ETH_HLEN + ETH_DATA_LEN, &info->dma[slot]);
-
- /* This is a Write Memory Barrier: it ensures that the entry in the
- * receive buffer array is written *before* we set the "used_len" entry
- * to 0. If the Host were looking at the receive buffer array from a
- * different CPU, it could potentially see "used_len = 0" and not see
- * the updated receive buffer information. This would be a horribly
- * nasty bug, so make sure the compiler and CPU know this has to happen
- * first. */
- wmb();
- /* Writing 0 to "used_len" tells the Host it can use this receive
- * buffer now. */
- info->dma[slot].used_len = 0;
- return 0;
-}
-
-/* This is the actual receive routine. When we receive an interrupt from the
- * Host to tell us a packet has been delivered, we arrive here: */
-static irqreturn_t lguestnet_rcv(int irq, void *dev_id)
-{
- struct net_device *dev = dev_id;
- struct lguestnet_info *info = netdev_priv(dev);
- unsigned int i, done = 0;
-
- /* Look through our entire receive array for an entry which has data
- * in it. */
- for (i = 0; i < ARRAY_SIZE(info->dma); i++) {
- unsigned int length;
- struct sk_buff *skb;
-
- length = info->dma[i].used_len;
- if (length == 0)
- continue;
-
- /* We've found one! Remember the skb (we grabbed the length
- * above), and immediately refill the slot we've taken it
- * from. */
- done++;
- skb = info->skb[i];
- fill_slot(dev, i);
-
- /* This shouldn't happen: micropackets could be sent by a
- * badly-behaved Guest on the network, but the Host will never
- * stuff more data in the buffer than the buffer length. */
- if (length < ETH_HLEN || length > ETH_HLEN + ETH_DATA_LEN) {
- pr_debug(KERN_WARNING "%s: unbelievable skb len: %i\n",
- dev->name, length);
- dev_kfree_skb(skb);
- continue;
- }
-
- /* skb_put(), what a great function! I've ranted about this
- * function before (http://lkml.org/lkml/1999/9/26/24). You
- * call it after you've added data to the end of an skb (in
- * this case, it was the Host which wrote the data). */
- skb_put(skb, length);
-
- /* The ethernet header contains a protocol field: we use the
- * standard helper to extract it, and place the result in
- * skb->protocol. The helper also sets up skb->pkt_type and
- * eats up the ethernet header from the front of the packet. */
- skb->protocol = eth_type_trans(skb, dev);
-
- /* If this device doesn't need checksums for sending, we also
- * don't need to check the packets when they come in. */
- if (dev->features & NETIF_F_NO_CSUM)
- skb->ip_summed = CHECKSUM_UNNECESSARY;
-
- /* As a last resort for debugging the driver or the lguest I/O
- * subsystem, you can uncomment the "#define DEBUG" at the top
- * of this file, which turns all the pr_debug() into printk()
- * and floods the logs. */
- pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
- ntohs(skb->protocol), skb->len, skb->pkt_type);
-
- /* Update the packet and byte counts (visible from ifconfig,
- * and good for debugging). */
- dev->stats.rx_bytes += skb->len;
- dev->stats.rx_packets++;
-
- /* Hand our fresh network packet into the stack's "network
- * interface receive" routine. That will free the packet
- * itself when it's finished. */
- netif_rx(skb);
- }
-
- /* If we found any packets, we assume the interrupt was for us. */
- return done ? IRQ_HANDLED : IRQ_NONE;
-}
-
-/*D:550 This is where we start: when the device is brought up by dhcpd or
- * ifconfig. At this point we advertise our MAC address to the rest of the
- * network, and register receive buffers ready for incoming packets. */
-static int lguestnet_open(struct net_device *dev)
-{
- int i;
- struct lguestnet_info *info = netdev_priv(dev);
-
- /* Copy our MAC address into the device page, so others on the network
- * can find us. */
- memcpy(info->peer[info->me].mac, dev->dev_addr, ETH_ALEN);
-
- /* We might already be in promisc mode (dev->flags & IFF_PROMISC). Our
- * set_multicast callback handles this already, so we call it now. */
- lguestnet_set_multicast(dev);
-
- /* Allocate packets and put them into our "struct lguest_dma" array.
- * If we fail to allocate all the packets we could still limp along,
- * but it's a sign of real stress so we should probably give up now. */
- for (i = 0; i < ARRAY_SIZE(info->dma); i++) {
- if (fill_slot(dev, i) != 0)
- goto cleanup;
- }
-
- /* Finally we tell the Host where our array of "struct lguest_dma"
- * receive buffers is, binding it to the key corresponding to the
- * device's physical memory plus our peerid. */
- if (lguest_bind_dma(peer_key(info,info->me), info->dma,
- NUM_SKBS, lgdev_irq(info->lgdev)) != 0)
- goto cleanup;
- return 0;
-
-cleanup:
- while (--i >= 0)
- dev_kfree_skb(info->skb[i]);
- return -ENOMEM;
-}
-/*:*/
-
-/* The close routine is called when the device is no longer in use: we clean up
- * elegantly. */
-static int lguestnet_close(struct net_device *dev)
-{
- unsigned int i;
- struct lguestnet_info *info = netdev_priv(dev);
-
- /* Clear all trace of our existence out of the device memory by setting
- * the slot which held our MAC address to 0 (unused). */
- memset(&info->peer[info->me], 0, sizeof(info->peer[info->me]));
-
- /* Unregister our array of receive buffers */
- lguest_unbind_dma(peer_key(info, info->me), info->dma);
- for (i = 0; i < ARRAY_SIZE(info->dma); i++)
- dev_kfree_skb(info->skb[i]);
- return 0;
-}
-
-/*D:510 The network device probe function is basically a standard ethernet
- * device setup. It reads the "struct lguest_device_desc" and sets the "struct
- * net_device". Oh, the line-by-line excitement! Let's skip over it. :*/
-static int lguestnet_probe(struct lguest_device *lgdev)
-{
- int err, irqf = IRQF_SHARED;
- struct net_device *dev;
- struct lguestnet_info *info;
- struct lguest_device_desc *desc = &lguest_devices[lgdev->index];
-
- pr_debug("lguest_net: probing for device %i\n", lgdev->index);
-
- dev = alloc_etherdev(sizeof(struct lguestnet_info));
- if (!dev)
- return -ENOMEM;
-
- /* Ethernet defaults with some changes */
- ether_setup(dev);
- dev->set_mac_address = NULL;
-
- dev->dev_addr[0] = 0x02; /* set local assignment bit (IEEE802) */
- dev->dev_addr[1] = 0x00;
- memcpy(&dev->dev_addr[2], &lguest_data.guestid, 2);
- dev->dev_addr[4] = 0x00;
- dev->dev_addr[5] = 0x00;
-
- dev->open = lguestnet_open;
- dev->stop = lguestnet_close;
- dev->hard_start_xmit = lguestnet_start_xmit;
-
- /* We don't actually support multicast yet, but turning on/off
- * promisc also calls dev->set_multicast_list. */
- dev->set_multicast_list = lguestnet_set_multicast;
- SET_NETDEV_DEV(dev, &lgdev->dev);
-
- /* The network code complains if you have "scatter-gather" capability
- * if you don't also handle checksums (it seem that would be
- * "illogical"). So we use a lie of omission and don't tell it that we
- * can handle scattered packets unless we also don't want checksums,
- * even though to us they're completely independent. */
- if (desc->features & LGUEST_NET_F_NOCSUM)
- dev->features = NETIF_F_SG|NETIF_F_NO_CSUM;
-
- info = netdev_priv(dev);
- info->mapsize = PAGE_SIZE * desc->num_pages;
- info->peer_phys = ((unsigned long)desc->pfn << PAGE_SHIFT);
- info->lgdev = lgdev;
- info->peer = lguest_map(info->peer_phys, desc->num_pages);
- if (!info->peer) {
- err = -ENOMEM;
- goto free;
- }
-
- /* This stores our peerid (upper bits reserved for future). */
- info->me = (desc->features & (info->mapsize-1));
-
- err = register_netdev(dev);
- if (err) {
- pr_debug("lguestnet: registering device failed\n");
- goto unmap;
- }
-
- if (lguest_devices[lgdev->index].features & LGUEST_DEVICE_F_RANDOMNESS)
- irqf |= IRQF_SAMPLE_RANDOM;
- if (request_irq(lgdev_irq(lgdev), lguestnet_rcv, irqf, "lguestnet",
- dev) != 0) {
- pr_debug("lguestnet: cannot get irq %i\n", lgdev_irq(lgdev));
- goto unregister;
- }
-
- pr_debug("lguestnet: registered device %s\n", dev->name);
- /* Finally, we put the "struct net_device" in the generic "struct
- * lguest_device"s private pointer. Again, it's not necessary, but
- * makes sure the cool kernel kids don't tease us. */
- lgdev->private = dev;
- return 0;
-
-unregister:
- unregister_netdev(dev);
-unmap:
- lguest_unmap(info->peer);
-free:
- free_netdev(dev);
- return err;
-}
-
-static struct lguest_driver lguestnet_drv = {
- .name = "lguestnet",
- .owner = THIS_MODULE,
- .device_type = LGUEST_DEVICE_T_NET,
- .probe = lguestnet_probe,
-};
-
-static __init int lguestnet_init(void)
-{
- return register_lguest_driver(&lguestnet_drv);
-}
-module_init(lguestnet_init);
-
-MODULE_DESCRIPTION("Lguest network driver");
-MODULE_LICENSE("GPL");
-
-/*D:580
- * This is the last of the Drivers, and with this we have covered the many and
- * wonderous and fine (and boring) details of the Guest.
- *
- * "make Launcher" beckons, where we answer questions like "Where do Guests
- * come from?", and "What do you do when someone asks for optimization?"
- */
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
new file mode 100644
index 00000000000..e396c9d2af8
--- /dev/null
+++ b/drivers/net/virtio_net.c
@@ -0,0 +1,435 @@
+/* A simple network driver using virtio.
+ *
+ * Copyright 2007 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+//#define DEBUG
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/module.h>
+#include <linux/virtio.h>
+#include <linux/virtio_net.h>
+#include <linux/scatterlist.h>
+
+/* FIXME: MTU in config. */
+#define MAX_PACKET_LEN (ETH_HLEN+ETH_DATA_LEN)
+
+struct virtnet_info
+{
+ struct virtio_device *vdev;
+ struct virtqueue *rvq, *svq;
+ struct net_device *dev;
+ struct napi_struct napi;
+
+ /* Number of input buffers, and max we've ever had. */
+ unsigned int num, max;
+
+ /* Receive & send queues. */
+ struct sk_buff_head recv;
+ struct sk_buff_head send;
+};
+
+static inline struct virtio_net_hdr *skb_vnet_hdr(struct sk_buff *skb)
+{
+ return (struct virtio_net_hdr *)skb->cb;
+}
+
+static inline void vnet_hdr_to_sg(struct scatterlist *sg, struct sk_buff *skb)
+{
+ sg_init_one(sg, skb_vnet_hdr(skb), sizeof(struct virtio_net_hdr));
+}
+
+static bool skb_xmit_done(struct virtqueue *rvq)
+{
+ struct virtnet_info *vi = rvq->vdev->priv;
+
+ /* In case we were waiting for output buffers. */
+ netif_wake_queue(vi->dev);
+ return true;
+}
+
+static void receive_skb(struct net_device *dev, struct sk_buff *skb,
+ unsigned len)
+{
+ struct virtio_net_hdr *hdr = skb_vnet_hdr(skb);
+
+ if (unlikely(len < sizeof(struct virtio_net_hdr) + ETH_HLEN)) {
+ pr_debug("%s: short packet %i\n", dev->name, len);
+ dev->stats.rx_length_errors++;
+ goto drop;
+ }
+ len -= sizeof(struct virtio_net_hdr);
+ BUG_ON(len > MAX_PACKET_LEN);
+
+ skb_trim(skb, len);
+ skb->protocol = eth_type_trans(skb, dev);
+ pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
+ ntohs(skb->protocol), skb->len, skb->pkt_type);
+ dev->stats.rx_bytes += skb->len;
+ dev->stats.rx_packets++;
+
+ if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
+ pr_debug("Needs csum!\n");
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ skb->csum_start = hdr->csum_start;
+ skb->csum_offset = hdr->csum_offset;
+ if (skb->csum_start > skb->len - 2
+ || skb->csum_offset > skb->len - 2) {
+ if (net_ratelimit())
+ printk(KERN_WARNING "%s: csum=%u/%u len=%u\n",
+ dev->name, skb->csum_start,
+ skb->csum_offset, skb->len);
+ goto frame_err;
+ }
+ }
+
+ if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
+ pr_debug("GSO!\n");
+ switch (hdr->gso_type) {
+ case VIRTIO_NET_HDR_GSO_TCPV4:
+ skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
+ break;
+ case VIRTIO_NET_HDR_GSO_TCPV4_ECN:
+ skb_shinfo(skb)->gso_type = SKB_GSO_TCP_ECN;
+ break;
+ case VIRTIO_NET_HDR_GSO_UDP:
+ skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
+ break;
+ case VIRTIO_NET_HDR_GSO_TCPV6:
+ skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
+ break;
+ default:
+ if (net_ratelimit())
+ printk(KERN_WARNING "%s: bad gso type %u.\n",
+ dev->name, hdr->gso_type);
+ goto frame_err;
+ }
+
+ skb_shinfo(skb)->gso_size = hdr->gso_size;
+ if (skb_shinfo(skb)->gso_size == 0) {
+ if (net_ratelimit())
+ printk(KERN_WARNING "%s: zero gso size.\n",
+ dev->name);
+ goto frame_err;
+ }
+
+ /* Header must be checked, and gso_segs computed. */
+ skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
+ skb_shinfo(skb)->gso_segs = 0;
+ }
+
+ netif_receive_skb(skb);
+ return;
+
+frame_err:
+ dev->stats.rx_frame_errors++;
+drop:
+ dev_kfree_skb(skb);
+}
+
+static void try_fill_recv(struct virtnet_info *vi)
+{
+ struct sk_buff *skb;
+ struct scatterlist sg[1+MAX_SKB_FRAGS];
+ int num, err;
+
+ for (;;) {
+ skb = netdev_alloc_skb(vi->dev, MAX_PACKET_LEN);
+ if (unlikely(!skb))
+ break;
+
+ skb_put(skb, MAX_PACKET_LEN);
+ vnet_hdr_to_sg(sg, skb);
+ num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
+ skb_queue_head(&vi->recv, skb);
+
+ err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb);
+ if (err) {
+ skb_unlink(skb, &vi->recv);
+ kfree_skb(skb);
+ break;
+ }
+ vi->num++;
+ }
+ if (unlikely(vi->num > vi->max))
+ vi->max = vi->num;
+ vi->rvq->vq_ops->kick(vi->rvq);
+}
+
+static bool skb_recv_done(struct virtqueue *rvq)
+{
+ struct virtnet_info *vi = rvq->vdev->priv;
+ netif_rx_schedule(vi->dev, &vi->napi);
+ /* Suppress further interrupts. */
+ return false;
+}
+
+static int virtnet_poll(struct napi_struct *napi, int budget)
+{
+ struct virtnet_info *vi = container_of(napi, struct virtnet_info, napi);
+ struct sk_buff *skb = NULL;
+ unsigned int len, received = 0;
+
+again:
+ while (received < budget &&
+ (skb = vi->rvq->vq_ops->get_buf(vi->rvq, &len)) != NULL) {
+ __skb_unlink(skb, &vi->recv);
+ receive_skb(vi->dev, skb, len);
+ vi->num--;
+ received++;
+ }
+
+ /* FIXME: If we oom and completely run out of inbufs, we need
+ * to start a timer trying to fill more. */
+ if (vi->num < vi->max / 2)
+ try_fill_recv(vi);
+
+ /* All done? */
+ if (!skb) {
+ netif_rx_complete(vi->dev, napi);
+ if (unlikely(!vi->rvq->vq_ops->restart(vi->rvq))
+ && netif_rx_reschedule(vi->dev, napi))
+ goto again;
+ }
+
+ return received;
+}
+
+static void free_old_xmit_skbs(struct virtnet_info *vi)
+{
+ struct sk_buff *skb;
+ unsigned int len;
+
+ while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
+ pr_debug("Sent skb %p\n", skb);
+ __skb_unlink(skb, &vi->send);
+ vi->dev->stats.tx_bytes += len;
+ vi->dev->stats.tx_packets++;
+ kfree_skb(skb);
+ }
+}
+
+static int start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct virtnet_info *vi = netdev_priv(dev);
+ int num, err;
+ struct scatterlist sg[1+MAX_SKB_FRAGS];
+ struct virtio_net_hdr *hdr;
+ const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
+ DECLARE_MAC_BUF(mac);
+
+ pr_debug("%s: xmit %p %s\n", dev->name, skb, print_mac(mac, dest));
+
+ free_old_xmit_skbs(vi);
+
+ /* Encode metadata header at front. */
+ hdr = skb_vnet_hdr(skb);
+ if (skb->ip_summed == CHECKSUM_PARTIAL) {
+ hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
+ hdr->csum_start = skb->csum_start - skb_headroom(skb);
+ hdr->csum_offset = skb->csum_offset;
+ } else {
+ hdr->flags = 0;
+ hdr->csum_offset = hdr->csum_start = 0;
+ }
+
+ if (skb_is_gso(skb)) {
+ hdr->gso_size = skb_shinfo(skb)->gso_size;
+ if (skb_shinfo(skb)->gso_type & SKB_GSO_TCP_ECN)
+ hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4_ECN;
+ else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
+ hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
+ else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
+ hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
+ else if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
+ hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
+ else
+ BUG();
+ } else {
+ hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
+ hdr->gso_size = 0;
+ }
+
+ vnet_hdr_to_sg(sg, skb);
+ num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
+ __skb_queue_head(&vi->send, skb);
+ err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
+ if (err) {
+ pr_debug("%s: virtio not prepared to send\n", dev->name);
+ skb_unlink(skb, &vi->send);
+ netif_stop_queue(dev);
+ return NETDEV_TX_BUSY;
+ }
+ vi->svq->vq_ops->kick(vi->svq);
+
+ return 0;
+}
+
+static int virtnet_open(struct net_device *dev)
+{
+ struct virtnet_info *vi = netdev_priv(dev);
+
+ try_fill_recv(vi);
+
+ /* If we didn't even get one input buffer, we're useless. */
+ if (vi->num == 0)
+ return -ENOMEM;
+
+ napi_enable(&vi->napi);
+ return 0;
+}
+
+static int virtnet_close(struct net_device *dev)
+{
+ struct virtnet_info *vi = netdev_priv(dev);
+ struct sk_buff *skb;
+
+ napi_disable(&vi->napi);
+
+ /* networking core has neutered skb_xmit_done/skb_recv_done, so don't
+ * worry about races vs. get(). */
+ vi->rvq->vq_ops->shutdown(vi->rvq);
+ while ((skb = __skb_dequeue(&vi->recv)) != NULL) {
+ kfree_skb(skb);
+ vi->num--;
+ }
+ vi->svq->vq_ops->shutdown(vi->svq);
+ while ((skb = __skb_dequeue(&vi->send)) != NULL)
+ kfree_skb(skb);
+
+ BUG_ON(vi->num != 0);
+ return 0;
+}
+
+static int virtnet_probe(struct virtio_device *vdev)
+{
+ int err;
+ unsigned int len;
+ struct net_device *dev;
+ struct virtnet_info *vi;
+ void *token;
+
+ /* Allocate ourselves a network device with room for our info */
+ dev = alloc_etherdev(sizeof(struct virtnet_info));
+ if (!dev)
+ return -ENOMEM;
+
+ /* Set up network device as normal. */
+ ether_setup(dev);
+ dev->open = virtnet_open;
+ dev->stop = virtnet_close;
+ dev->hard_start_xmit = start_xmit;
+ dev->features = NETIF_F_HIGHDMA;
+ SET_NETDEV_DEV(dev, &vdev->dev);
+
+ /* Do we support "hardware" checksums? */
+ token = vdev->config->find(vdev, VIRTIO_CONFIG_NET_F, &len);
+ if (virtio_use_bit(vdev, token, len, VIRTIO_NET_F_NO_CSUM)) {
+ /* This opens up the world of extra features. */
+ dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
+ if (virtio_use_bit(vdev, token, len, VIRTIO_NET_F_TSO4))
+ dev->features |= NETIF_F_TSO;
+ if (virtio_use_bit(vdev, token, len, VIRTIO_NET_F_UFO))
+ dev->features |= NETIF_F_UFO;
+ if (virtio_use_bit(vdev, token, len, VIRTIO_NET_F_TSO4_ECN))
+ dev->features |= NETIF_F_TSO_ECN;
+ if (virtio_use_bit(vdev, token, len, VIRTIO_NET_F_TSO6))
+ dev->features |= NETIF_F_TSO6;
+ }
+
+ /* Configuration may specify what MAC to use. Otherwise random. */
+ token = vdev->config->find(vdev, VIRTIO_CONFIG_NET_MAC_F, &len);
+ if (token) {
+ dev->addr_len = len;
+ vdev->config->get(vdev, token, dev->dev_addr, len);
+ } else
+ random_ether_addr(dev->dev_addr);
+
+ /* Set up our device-specific information */
+ vi = netdev_priv(dev);
+ netif_napi_add(dev, &vi->napi, virtnet_poll, 16);
+ vi->dev = dev;
+ vi->vdev = vdev;
+
+ /* We expect two virtqueues, receive then send. */
+ vi->rvq = vdev->config->find_vq(vdev, skb_recv_done);
+ if (IS_ERR(vi->rvq)) {
+ err = PTR_ERR(vi->rvq);
+ goto free;
+ }
+
+ vi->svq = vdev->config->find_vq(vdev, skb_xmit_done);
+ if (IS_ERR(vi->svq)) {
+ err = PTR_ERR(vi->svq);
+ goto free_recv;
+ }
+
+ /* Initialize our empty receive and send queues. */
+ skb_queue_head_init(&vi->recv);
+ skb_queue_head_init(&vi->send);
+
+ err = register_netdev(dev);
+ if (err) {
+ pr_debug("virtio_net: registering device failed\n");
+ goto free_send;
+ }
+ pr_debug("virtnet: registered device %s\n", dev->name);
+ vdev->priv = vi;
+ return 0;
+
+free_send:
+ vdev->config->del_vq(vi->svq);
+free_recv:
+ vdev->config->del_vq(vi->rvq);
+free:
+ free_netdev(dev);
+ return err;
+}
+
+static void virtnet_remove(struct virtio_device *vdev)
+{
+ unregister_netdev(vdev->priv);
+ free_netdev(vdev->priv);
+}
+
+static struct virtio_device_id id_table[] = {
+ { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
+ { 0 },
+};
+
+static struct virtio_driver virtio_net = {
+ .driver.name = KBUILD_MODNAME,
+ .driver.owner = THIS_MODULE,
+ .id_table = id_table,
+ .probe = virtnet_probe,
+ .remove = __devexit_p(virtnet_remove),
+};
+
+static int __init init(void)
+{
+ return register_virtio_driver(&virtio_net);
+}
+
+static void __exit fini(void)
+{
+ unregister_virtio_driver(&virtio_net);
+}
+module_init(init);
+module_exit(fini);
+
+MODULE_DEVICE_TABLE(virtio, id_table);
+MODULE_DESCRIPTION("Virtio network driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
new file mode 100644
index 00000000000..9e33fc4da87
--- /dev/null
+++ b/drivers/virtio/Kconfig
@@ -0,0 +1,8 @@
+# Virtio always gets selected by whoever wants it.
+config VIRTIO
+ bool
+
+# Similarly the virtio ring implementation.
+config VIRTIO_RING
+ bool
+ depends on VIRTIO
diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
new file mode 100644
index 00000000000..f70e40971dd
--- /dev/null
+++ b/drivers/virtio/Makefile
@@ -0,0 +1,2 @@
+obj-$(CONFIG_VIRTIO) += virtio.o
+obj-$(CONFIG_VIRTIO_RING) += virtio_ring.o
diff --git a/drivers/virtio/config.c b/drivers/virtio/config.c
new file mode 100644
index 00000000000..983d482fba4
--- /dev/null
+++ b/drivers/virtio/config.c
@@ -0,0 +1,13 @@
+/* Configuration space parsing helpers for virtio.
+ *
+ * The configuration is [type][len][... len bytes ...] fields.
+ *
+ * Copyright 2007 Rusty Russell, IBM Corporation.
+ * GPL v2 or later.
+ */
+#include <linux/err.h>
+#include <linux/virtio.h>
+#include <linux/virtio_config.h>
+#include <linux/bug.h>
+#include <asm/system.h>
+
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
new file mode 100644
index 00000000000..15d7787dea8
--- /dev/null
+++ b/drivers/virtio/virtio.c
@@ -0,0 +1,189 @@
+#include <linux/virtio.h>
+#include <linux/spinlock.h>
+#include <linux/virtio_config.h>
+
+static ssize_t device_show(struct device *_d,
+ struct device_attribute *attr, char *buf)
+{
+ struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
+ return sprintf(buf, "%hu", dev->id.device);
+}
+static ssize_t vendor_show(struct device *_d,
+ struct device_attribute *attr, char *buf)
+{
+ struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
+ return sprintf(buf, "%hu", dev->id.vendor);
+}
+static ssize_t status_show(struct device *_d,
+ struct device_attribute *attr, char *buf)
+{
+ struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
+ return sprintf(buf, "0x%08x", dev->config->get_status(dev));
+}
+static ssize_t modalias_show(struct device *_d,
+ struct device_attribute *attr, char *buf)
+{
+ struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
+
+ return sprintf(buf, "virtio:d%08Xv%08X\n",
+ dev->id.device, dev->id.vendor);
+}
+static struct device_attribute virtio_dev_attrs[] = {
+ __ATTR_RO(device),
+ __ATTR_RO(vendor),
+ __ATTR_RO(status),
+ __ATTR_RO(modalias),
+ __ATTR_NULL
+};
+
+static inline int virtio_id_match(const struct virtio_device *dev,
+ const struct virtio_device_id *id)
+{
+ if (id->device != dev->id.device)
+ return 0;
+
+ return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor != dev->id.vendor;
+}
+
+/* This looks through all the IDs a driver claims to support. If any of them
+ * match, we return 1 and the kernel will call virtio_dev_probe(). */
+static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
+{
+ unsigned int i;
+ struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
+ const struct virtio_device_id *ids;
+
+ ids = container_of(_dr, struct virtio_driver, driver)->id_table;
+ for (i = 0; ids[i].device; i++)
+ if (virtio_id_match(dev, &ids[i]))
+ return 1;
+ return 0;
+}
+
+static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
+{
+ struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
+
+ return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X",
+ dev->id.device, dev->id.vendor);
+}
+
+static struct bus_type virtio_bus = {
+ .name = "virtio",
+ .match = virtio_dev_match,
+ .dev_attrs = virtio_dev_attrs,
+ .uevent = virtio_uevent,
+};
+
+static void add_status(struct virtio_device *dev, unsigned status)
+{
+ dev->config->set_status(dev, dev->config->get_status(dev) | status);
+}
+
+static int virtio_dev_probe(struct device *_d)
+{
+ int err;
+ struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
+ struct virtio_driver *drv = container_of(dev->dev.driver,
+ struct virtio_driver, driver);
+
+ add_status(dev, VIRTIO_CONFIG_S_DRIVER);
+ err = drv->probe(dev);
+ if (err)
+ add_status(dev, VIRTIO_CONFIG_S_FAILED);
+ else
+ add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
+ return err;
+}
+
+int register_virtio_driver(struct virtio_driver *driver)
+{
+ driver->driver.bus = &virtio_bus;
+ driver->driver.probe = virtio_dev_probe;
+ return driver_register(&driver->driver);
+}
+EXPORT_SYMBOL_GPL(register_virtio_driver);
+
+void unregister_virtio_driver(struct virtio_driver *driver)
+{
+ driver_unregister(&driver->driver);
+}
+EXPORT_SYMBOL_GPL(unregister_virtio_driver);
+
+int register_virtio_device(struct virtio_device *dev)
+{
+ int err;
+
+ dev->dev.bus = &virtio_bus;
+ sprintf(dev->dev.bus_id, "%u", dev->index);
+
+ /* Acknowledge that we've seen the device. */
+ add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
+
+ /* device_register() causes the bus infrastructure to look for a
+ * matching driver. */
+ err = device_register(&dev->dev);
+ if (err)
+ add_status(dev, VIRTIO_CONFIG_S_FAILED);
+ return err;
+}
+EXPORT_SYMBOL_GPL(register_virtio_device);
+
+void unregister_virtio_device(struct virtio_device *dev)
+{
+ device_unregister(&dev->dev);
+}
+EXPORT_SYMBOL_GPL(unregister_virtio_device);
+
+int __virtio_config_val(struct virtio_device *vdev,
+ u8 type, void *val, size_t size)
+{
+ void *token;
+ unsigned int len;
+
+ token = vdev->config->find(vdev, type, &len);
+ if (!token)
+ return -ENOENT;
+
+ if (len != size)
+ return -EIO;
+
+ vdev->config->get(vdev, token, val, size);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__virtio_config_val);
+
+int virtio_use_bit(struct virtio_device *vdev,
+ void *token, unsigned int len, unsigned int bitnum)
+{
+ unsigned long bits[16];
+
+ /* This makes it convenient to pass-through find() results. */
+ if (!token)
+ return 0;
+
+ /* bit not in range of this bitfield? */
+ if (bitnum * 8 >= len / 2)
+ return 0;
+
+ /* Giant feature bitfields are silly. */
+ BUG_ON(len > sizeof(bits));
+ vdev->config->get(vdev, token, bits, len);
+
+ if (!test_bit(bitnum, bits))
+ return 0;
+
+ /* Set acknowledge bit, and write it back. */
+ set_bit(bitnum + len * 8 / 2, bits);
+ vdev->config->set(vdev, token, bits, len);
+ return 1;
+}
+EXPORT_SYMBOL_GPL(virtio_use_bit);
+
+static int virtio_init(void)
+{
+ if (bus_register(&virtio_bus) != 0)
+ panic("virtio bus registration failed");
+ return 0;
+}
+core_initcall(virtio_init);
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
new file mode 100644
index 00000000000..0e4baca21b8
--- /dev/null
+++ b/drivers/virtio/virtio_ring.c
@@ -0,0 +1,313 @@
+/* Virtio ring implementation.
+ *
+ * Copyright 2007 Rusty Russell IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include <linux/virtio.h>
+#include <linux/virtio_ring.h>
+#include <linux/device.h>
+
+#ifdef DEBUG
+/* For development, we want to crash whenever the ring is screwed. */
+#define BAD_RING(vq, fmt...) \
+ do { dev_err(&vq->vq.vdev->dev, fmt); BUG(); } while(0)
+#define START_USE(vq) \
+ do { if ((vq)->in_use) panic("in_use = %i\n", (vq)->in_use); (vq)->in_use = __LINE__; mb(); } while(0)
+#define END_USE(vq) \
+ do { BUG_ON(!(vq)->in_use); (vq)->in_use = 0; mb(); } while(0)
+#else
+#define BAD_RING(vq, fmt...) \
+ do { dev_err(&vq->vq.vdev->dev, fmt); (vq)->broken = true; } while(0)
+#define START_USE(vq)
+#define END_USE(vq)
+#endif
+
+struct vring_virtqueue
+{
+ struct virtqueue vq;
+
+ /* Actual memory layout for this queue */
+ struct vring vring;
+
+ /* Other side has made a mess, don't try any more. */
+ bool broken;
+
+ /* Number of free buffers */
+ unsigned int num_free;
+ /* Head of free buffer list. */
+ unsigned int free_head;
+ /* Number we've added since last sync. */
+ unsigned int num_added;
+
+ /* Last used index we've seen. */
+ unsigned int last_used_idx;
+
+ /* How to notify other side. FIXME: commonalize hcalls! */
+ void (*notify)(struct virtqueue *vq);
+
+#ifdef DEBUG
+ /* They're supposed to lock for us. */
+ unsigned int in_use;
+#endif
+
+ /* Tokens for callbacks. */
+ void *data[];
+};
+
+#define to_vvq(_vq) container_of(_vq, struct vring_virtqueue, vq)
+
+static int vring_add_buf(struct virtqueue *_vq,
+ struct scatterlist sg[],
+ unsigned int out,
+ unsigned int in,
+ void *data)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+ unsigned int i, avail, head, uninitialized_var(prev);
+
+ BUG_ON(data == NULL);
+ BUG_ON(out + in > vq->vring.num);
+ BUG_ON(out + in == 0);
+
+ START_USE(vq);
+
+ if (vq->num_free < out + in) {
+ pr_debug("Can't add buf len %i - avail = %i\n",
+ out + in, vq->num_free);
+ END_USE(vq);
+ return -ENOSPC;
+ }
+
+ /* We're about to use some buffers from the free list. */
+ vq->num_free -= out + in;
+
+ head = vq->free_head;
+ for (i = vq->free_head; out; i = vq->vring.desc[i].next, out--) {
+ vq->vring.desc[i].flags = VRING_DESC_F_NEXT;
+ vq->vring.desc[i].addr = (page_to_pfn(sg_page(sg))<<PAGE_SHIFT)
+ + sg->offset;
+ vq->vring.desc[i].len = sg->length;
+ prev = i;
+ sg++;
+ }
+ for (; in; i = vq->vring.desc[i].next, in--) {
+ vq->vring.desc[i].flags = VRING_DESC_F_NEXT|VRING_DESC_F_WRITE;
+ vq->vring.desc[i].addr = (page_to_pfn(sg_page(sg))<<PAGE_SHIFT)
+ + sg->offset;
+ vq->vring.desc[i].len = sg->length;
+ prev = i;
+ sg++;
+ }
+ /* Last one doesn't continue. */
+ vq->vring.desc[prev].flags &= ~VRING_DESC_F_NEXT;
+
+ /* Update free pointer */
+ vq->free_head = i;
+
+ /* Set token. */
+ vq->data[head] = data;
+
+ /* Put entry in available array (but don't update avail->idx until they
+ * do sync). FIXME: avoid modulus here? */
+ avail = (vq->vring.avail->idx + vq->num_added++) % vq->vring.num;
+ vq->vring.avail->ring[avail] = head;
+
+ pr_debug("Added buffer head %i to %p\n", head, vq);
+ END_USE(vq);
+ return 0;
+}
+
+static void vring_kick(struct virtqueue *_vq)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+ START_USE(vq);
+ /* Descriptors and available array need to be set before we expose the
+ * new available array entries. */
+ wmb();
+
+ vq->vring.avail->idx += vq->num_added;
+ vq->num_added = 0;
+
+ /* Need to update avail index before checking if we should notify */
+ mb();
+
+ if (!(vq->vring.used->flags & VRING_USED_F_NO_NOTIFY))
+ /* Prod other side to tell it about changes. */
+ vq->notify(&vq->vq);
+
+ END_USE(vq);
+}
+
+static void detach_buf(struct vring_virtqueue *vq, unsigned int head)
+{
+ unsigned int i;
+
+ /* Clear data ptr. */
+ vq->data[head] = NULL;
+
+ /* Put back on free list: find end */
+ i = head;
+ while (vq->vring.desc[i].flags & VRING_DESC_F_NEXT) {
+ i = vq->vring.desc[i].next;
+ vq->num_free++;
+ }
+
+ vq->vring.desc[i].next = vq->free_head;
+ vq->free_head = head;
+ /* Plus final descriptor */
+ vq->num_free++;
+}
+
+/* FIXME: We need to tell other side about removal, to synchronize. */
+static void vring_shutdown(struct virtqueue *_vq)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+ unsigned int i;
+
+ for (i = 0; i < vq->vring.num; i++)
+ detach_buf(vq, i);
+}
+
+static inline bool more_used(const struct vring_virtqueue *vq)
+{
+ return vq->last_used_idx != vq->vring.used->idx;
+}
+
+static void *vring_get_buf(struct virtqueue *_vq, unsigned int *len)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+ void *ret;
+ unsigned int i;
+
+ START_USE(vq);
+
+ if (!more_used(vq)) {
+ pr_debug("No more buffers in queue\n");
+ END_USE(vq);
+ return NULL;
+ }
+
+ i = vq->vring.used->ring[vq->last_used_idx%vq->vring.num].id;
+ *len = vq->vring.used->ring[vq->last_used_idx%vq->vring.num].len;
+
+ if (unlikely(i >= vq->vring.num)) {
+ BAD_RING(vq, "id %u out of range\n", i);
+ return NULL;
+ }
+ if (unlikely(!vq->data[i])) {
+ BAD_RING(vq, "id %u is not a head!\n", i);
+ return NULL;
+ }
+
+ /* detach_buf clears data, so grab it now. */
+ ret = vq->data[i];
+ detach_buf(vq, i);
+ vq->last_used_idx++;
+ END_USE(vq);
+ return ret;
+}
+
+static bool vring_restart(struct virtqueue *_vq)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+
+ START_USE(vq);
+ BUG_ON(!(vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT));
+
+ /* We optimistically turn back on interrupts, then check if there was
+ * more to do. */
+ vq->vring.avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT;
+ mb();
+ if (unlikely(more_used(vq))) {
+ vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
+ END_USE(vq);
+ return false;
+ }
+
+ END_USE(vq);
+ return true;
+}
+
+irqreturn_t vring_interrupt(int irq, void *_vq)
+{
+ struct vring_virtqueue *vq = to_vvq(_vq);
+
+ if (!more_used(vq)) {
+ pr_debug("virtqueue interrupt with no work for %p\n", vq);
+ return IRQ_NONE;
+ }
+
+ if (unlikely(vq->broken))
+ return IRQ_HANDLED;
+
+ pr_debug("virtqueue callback for %p (%p)\n", vq, vq->vq.callback);
+ if (vq->vq.callback && !vq->vq.callback(&vq->vq))
+ vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
+
+ return IRQ_HANDLED;
+}
+
+static struct virtqueue_ops vring_vq_ops = {
+ .add_buf = vring_add_buf,
+ .get_buf = vring_get_buf,
+ .kick = vring_kick,
+ .restart = vring_restart,
+ .shutdown = vring_shutdown,
+};
+
+struct virtqueue *vring_new_virtqueue(unsigned int num,
+ struct virtio_device *vdev,
+ void *pages,
+ void (*notify)(struct virtqueue *),
+ bool (*callback)(struct virtqueue *))
+{
+ struct vring_virtqueue *vq;
+ unsigned int i;
+
+ vq = kmalloc(sizeof(*vq) + sizeof(void *)*num, GFP_KERNEL);
+ if (!vq)
+ return NULL;
+
+ vring_init(&vq->vring, num, pages);
+ vq->vq.callback = callback;
+ vq->vq.vdev = vdev;
+ vq->vq.vq_ops = &vring_vq_ops;
+ vq->notify = notify;
+ vq->broken = false;
+ vq->last_used_idx = 0;
+ vq->num_added = 0;
+#ifdef DEBUG
+ vq->in_use = false;
+#endif
+
+ /* No callback? Tell other side not to bother us. */
+ if (!callback)
+ vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
+
+ /* Put everything in free lists. */
+ vq->num_free = num;
+ vq->free_head = 0;
+ for (i = 0; i < num-1; i++)
+ vq->vring.desc[i].next = i+1;
+
+ return &vq->vq;
+}
+
+void vring_del_virtqueue(struct virtqueue *vq)
+{
+ kfree(to_vvq(vq));
+}
+