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2010-04-22virtio: Fix GFP flags passed from the virtio balloon driverBalbir Singh
The virtio balloon driver can dig into the reservation pools of the OS to satisfy a balloon request. This is not advisable and other balloon drivers (drivers/xen/balloon.c) avoid this as well. The patch also adds changes to avoid printing a warning if allocation fails, since we retry after sometime anyway. Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: kvm <kvm@vger.kernel.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-02virtio: set pci bus master enable bitMichael S. Tsirkin
As all virtio devices perform DMA, we must enable bus mastering for them to be spec compliant. This patch fixes hotplug of virtio devices with Linux guests and qemu 0.11-0.12. Tested-by: Alexander Graf <agraf@suse.de> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-02-28virtio: fix out of range array accessMichael S. Tsirkin
I have observed the following error on virtio-net module unload: ------------[ cut here ]------------ WARNING: at kernel/irq/manage.c:858 __free_irq+0xa0/0x14c() Hardware name: Bochs Trying to free already-free IRQ 0 Modules linked in: virtio_net(-) virtio_blk virtio_pci virtio_ring virtio af_packet e1000 shpchp aacraid uhci_hcd ohci_hcd ehci_hcd [last unloaded: scsi_wait_scan] Pid: 1957, comm: rmmod Not tainted 2.6.33-rc8-vhost #24 Call Trace: [<ffffffff8103e195>] warn_slowpath_common+0x7c/0x94 [<ffffffff8103e204>] warn_slowpath_fmt+0x41/0x43 [<ffffffff810a7a36>] ? __free_pages+0x5a/0x70 [<ffffffff8107cc00>] __free_irq+0xa0/0x14c [<ffffffff8107cceb>] free_irq+0x3f/0x65 [<ffffffffa0081424>] vp_del_vqs+0x81/0xb1 [virtio_pci] [<ffffffffa0091d29>] virtnet_remove+0xda/0x10b [virtio_net] [<ffffffffa0075200>] virtio_dev_remove+0x22/0x4a [virtio] [<ffffffff812709ee>] __device_release_driver+0x66/0xac [<ffffffff81270ab7>] driver_detach+0x83/0xa9 [<ffffffff8126fc66>] bus_remove_driver+0x91/0xb4 [<ffffffff81270fcf>] driver_unregister+0x6c/0x74 [<ffffffffa0075418>] unregister_virtio_driver+0xe/0x10 [virtio] [<ffffffffa0091c4d>] fini+0x15/0x17 [virtio_net] [<ffffffff8106997b>] sys_delete_module+0x1c3/0x230 [<ffffffff81007465>] ? old_ich_force_enable_hpet+0x117/0x164 [<ffffffff813bb720>] ? do_page_fault+0x29c/0x2cc [<ffffffff81028e58>] sysenter_dispatch+0x7/0x27 ---[ end trace 15e88e4c576cc62b ]--- The bug is in virtio-pci: we use msix_vector as array index to get irq entry, but some vqs do not have a dedicated vector so this causes an out of bounds access. By chance, we seem to often get 0 value, which results in this error. Fix by verifying that vector is legal before using it as index. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Anthony Liguori <aliguori@us.ibm.com> Acked-by: Shirley Ma <xma@us.ibm.com> Acked-by: Amit Shah <amit.shah@redhat.com>
2010-02-24virtio: Initialize vq->data entries to NULLAmit Shah
vq operations depend on vq->data[i] being NULL to figure out if the vq entry is in use (since the previous patch). We have to initialize them to NULL to ensure we don't work with junk data and trigger false BUG_ONs. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Shirley Ma <xma@us.ibm.com>
2010-02-24virtio: Add ability to detach unused buffers from vringsShirley Ma
There's currently no way for a virtio driver to ask for unused buffers, so it has to keep a list itself to reclaim them at shutdown. This is redundant, since virtio_ring stores that information. So add a new hook to do this. Signed-off-by: Shirley Ma <xma@us.ibm.com> Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-02-24virtio: use smp_XX barriers on SMPMichael S. Tsirkin
virtio is communicating with a virtual "device" that actually runs on another host processor. Thus SMP barriers can be used to control memory access ordering. Where possible, we should use SMP barriers which are more lightweight than mandatory barriers, because mandatory barriers also control MMIO effects on accesses through relaxed memory I/O windows (which virtio does not use) (compare specifically smp_rmb and rmb on x86_64). We can't just use smp_mb and friends though, because we must force memory ordering even if guest is UP since host could be running on another CPU, but SMP barriers are defined to barrier() in that configuration. So, for UP fall back to mandatory barriers instead. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-02-24virtio: remove bogus barriers from DEBUG version of virtio_ring.cRusty Russell
With DEBUG defined, we add an ->in_use flag to detect if the caller invokes two virtio methods in parallel. The barriers attempt to ensure timely update of the ->in_use flag. But they're voodoo: if we need these barriers it implies that the calling code doesn't have sufficient synchronization to ensure the code paths aren't invoked at the same time anyway, and we want to detect it. Also, adding barriers changes timing, so turning on debug has more chance of hiding real problems. Thanks to MST for drawing my attention to this code... CC: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-02-24virtio: fix balloon without VIRTIO_BALLOON_F_STATS_VQRusty Russell
When running under qemu-kvm-0.11.0: BUG: unable to handle kernel paging request at 56e58955 ... Process vballoon (pid: 1297, ti=c7976000 task=c70a6ca0 task.ti=c7 ... Call Trace: [<c88253a3>] ? balloon+0x1b3/0x440 [virtio_balloon] [<c041c2d7>] ? schedule+0x327/0x9d0 [<c88251f0>] ? balloon+0x0/0x440 [virtio_balloon] [<c014a2d4>] ? kthread+0x74/0x80 [<c014a260>] ? kthread+0x0/0x80 [<c0103b36>] ? kernel_thread_helper+0x6/0x30 need_stats_update should be zero-initialized. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Adam Litke <agl@us.ibm.com>
2010-02-24virtio: Fix scheduling while atomic in virtio_balloon statsAdam Litke
This is a fix for my earlier patch: "virtio: Add memory statistics reporting to the balloon driver (V4)". I discovered that all_vm_events() can sleep and therefore stats collection cannot be done in interrupt context. One solution is to handle the interrupt by noting that stats need to be collected and waking the existing vballoon kthread which will complete the work via stats_handle_request(). Rusty, is this a saner way of doing business? There is one issue that I would like a broader opinion on. In stats_request, I update vb->need_stats_update and then wake up the kthread. The kthread uses vb->need_stats_update as a condition variable. Do I need a memory barrier between the update and wake_up to ensure that my kthread sees the correct value? My testing suggests that it is not needed but I would like some confirmation from the experts. Signed-off-by: Adam Litke <agl@us.ibm.com> To: Rusty Russell <rusty@rustcorp.com.au> Cc: Anthony Liguori <aliguori@linux.vnet.ibm.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-02-24virtio: Add memory statistics reporting to the balloon driver (V4)Adam Litke
Changes since V3: - Do not do endian conversions as they will be done in the host - Report stats that reference a quantity of memory in bytes - Minor coding style updates Changes since V2: - Increase stat field size to 64 bits - Report all sizes in kb (not pages) - Drop anon_pages stat and fix endianness conversion Changes since V1: - Use a virtqueue instead of the device config space When using ballooning to manage overcommitted memory on a host, a system for guests to communicate their memory usage to the host can provide information that will minimize the impact of ballooning on the guests. The current method employs a daemon running in each guest that communicates memory statistics to a host daemon at a specified time interval. The host daemon aggregates this information and inflates and/or deflates balloons according to the level of host memory pressure. This approach is effective but overly complex since a daemon must be installed inside each guest and coordinated to communicate with the host. A simpler approach is to collect memory statistics in the virtio balloon driver and communicate them directly to the hypervisor. This patch enables the guest-side support by adding stats collection and reporting to the virtio balloon driver. Signed-off-by: Adam Litke <agl@us.ibm.com> Cc: Anthony Liguori <anthony@codemonkey.ws> Cc: virtualization@lists.linux-foundation.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (minor fixes)
2010-02-24Add __devexit_p around reference to virtio_pci_removeJamie Lokier
This is needed to compile with CONFIG_VIRTIO_PCI=y, because virtio_pci_remove is marked __devexit. Signed-off-by: Jamie Lokier <jamie@shareable.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-01-16virtio: fix section mismatch warningsJeff Mahoney
Fix fixes the following warnings by renaming the driver structures to be suffixed with _driver. WARNING: drivers/virtio/virtio_balloon.o(.data+0x88): Section mismatch in reference from the variable virtio_balloon to the function .devexit.text:virtballoon_remove() WARNING: drivers/char/hw_random/virtio-rng.o(.data+0x88): Section mismatch in reference from the variable virtio_rng to the function .devexit.text:virtrng_remove() Signed-off-by: Jeff Mahoney <jeffm@suse.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-29virtio: order used ring after used index readMichael S. Tsirkin
On SMP guests, reads from the ring might bypass used index reads. This causes guest crashes because host writes to used index to signal ring data readiness. Fix this by inserting rmb before used ring reads. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
2009-10-29virtio-pci: fix per-vq MSI-X request logicMichael S. Tsirkin
Commit f68d24082e22ccee3077d11aeb6dc5354f0ca7f1 in 2.6.32-rc1 broke requesting IRQs for per-VQ MSI-X vectors: - vector number was used instead of the vector itself - we try to request an IRQ for VQ which does not have a callback handler This is a regression that causes warnings in kernel log, potentially lower performance as we need to scan vq list, and might cause system failure if the interrupt requested is in fact needed by another system. This was not noticed earlier because in most cases we were falling back on shared interrupt for all vqs. The warnings often look like this: virtio-pci 0000:00:03.0: irq 26 for MSI/MSI-X virtio-pci 0000:00:03.0: irq 27 for MSI/MSI-X virtio-pci 0000:00:03.0: irq 28 for MSI/MSI-X IRQ handler type mismatch for IRQ 1 current handler: i8042 Pid: 2400, comm: modprobe Tainted: G W 2.6.32-rc3-11952-gf3ed8d8-dirty #1 Call Trace: [<ffffffff81072aed>] ? __setup_irq+0x299/0x304 [<ffffffff81072ff3>] ? request_threaded_irq+0x144/0x1c1 [<ffffffff813455af>] ? vring_interrupt+0x0/0x30 [<ffffffff81346598>] ? vp_try_to_find_vqs+0x583/0x5c7 [<ffffffffa0015188>] ? skb_recv_done+0x0/0x34 [virtio_net] [<ffffffff81346609>] ? vp_find_vqs+0x2d/0x83 [<ffffffff81345d00>] ? vp_get+0x3c/0x4e [<ffffffffa0016373>] ? virtnet_probe+0x2f1/0x428 [virtio_net] [<ffffffffa0015188>] ? skb_recv_done+0x0/0x34 [virtio_net] [<ffffffffa00150d8>] ? skb_xmit_done+0x0/0x39 [virtio_net] [<ffffffff8110ab92>] ? sysfs_do_create_link+0xcb/0x116 [<ffffffff81345cc2>] ? vp_get_status+0x14/0x16 [<ffffffff81345464>] ? virtio_dev_probe+0xa9/0xc8 [<ffffffff8122b11c>] ? driver_probe_device+0x8d/0x128 [<ffffffff8122b206>] ? __driver_attach+0x4f/0x6f [<ffffffff8122b1b7>] ? __driver_attach+0x0/0x6f [<ffffffff8122a9f9>] ? bus_for_each_dev+0x43/0x74 [<ffffffff8122a374>] ? bus_add_driver+0xea/0x22d [<ffffffff8122b4a3>] ? driver_register+0xa7/0x111 [<ffffffffa001a000>] ? init+0x0/0xc [virtio_net] [<ffffffff81009051>] ? do_one_initcall+0x50/0x148 [<ffffffff8106e117>] ? sys_init_module+0xc5/0x21a [<ffffffff8100af02>] ? system_call_fastpath+0x16/0x1b virtio-pci 0000:00:03.0: irq 26 for MSI/MSI-X virtio-pci 0000:00:03.0: irq 27 for MSI/MSI-X Reported-by: Marcelo Tosatti <mtosatti@redhat.com> Reported-by: Shirley Ma <xma@us.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-10-22move virtballoon_remove to .devexit.textUwe Kleine-König
The function virtballoon_remove is used only wrapped by __devexit_p so define it using __devexit. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-10-22virtio: let header files include virtio_ids.hChristian Borntraeger
Rusty, commit 3ca4f5ca73057a617f9444a91022d7127041970a virtio: add virtio IDs file moved all device IDs into a single file. While the change itself is a very good one, it can break userspace applications. For example if a userspace tool wanted to get the ID of virtio_net it used to include virtio_net.h. This does no longer work, since virtio_net.h does not include virtio_ids.h. This patch moves all "#include <linux/virtio_ids.h>" from the C files into the header files, making the header files compatible with the old ones. In addition, this patch exports virtio_ids.h to userspace. CC: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-09-23virtio: add virtio IDs fileFernando Luis Vazquez Cao
Virtio IDs are spread all over the tree which makes assigning new IDs bothersome. Putting them together should make the process less error-prone. Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-09-23virtio: make add_buf return capacity remainingRusty Russell
This API change means that virtio_net can tell how much capacity remains for buffers. It's necessarily fuzzy, since VIRTIO_RING_F_INDIRECT_DESC means we can fit any number of descriptors in one, *if* we can kmalloc. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Dinesh Subhraveti <dineshs@us.ibm.com>
2009-09-23virtio_pci: minor MSI-X cleanupsRusty Russell
1) Rename vp_request_vectors to vp_request_msix_vectors, and take non-MSI-X case out to caller. 2) Comment weird pci_enable_msix API 3) Rename vp_find_vq to setup_vq. 4) Fix spaces to tabs 5) Make nvectors calc internal to vp_try_to_find_vqs() 6) Rename vector to msix_vector for more clarity. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com>
2009-07-30virtio: refactor find_vqsMichael S. Tsirkin
This refactors find_vqs, making it more readable and robust, and fixing two regressions from 2.6.30: - double free_irq causing BUG_ON on device removal - probe failure when vq can't be assigned to msi-x vector (reported on old host kernels) Tested-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-07-30virtio: delete vq from listMichael S. Tsirkin
This makes delete vq the reverse of find vq. This is required to make it possible to retry find_vqs after a failure, otherwise the list gets corrupted. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-07-30virtio: fix memory leak on device removalMichael S. Tsirkin
Make vp_free_vectors do the reverse of vq_request_vectors. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-07-17virtio-pci: correctly unregister root device on errorMark McLoughlin
If pci_register_driver() fails we're incorrectly unregistering the root device with device_unregister() rather than root_device_unregister(). Reported-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio: enhance id_matching for virtio driversChristian Borntraeger
This patch allows a virtio driver to use VIRTIO_DEV_ANY_ID for the device id. This will be used by a test module that can be bound to any virtio device. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio: fix id_matching for virtio driversChristian Borntraeger
This bug never appeared, since all current virtio drivers use VIRTIO_DEV_ANY_ID for the vendor field. If a real vendor would be used, the check in virtio_id_match is wrong - it returns 0 if id->vendor == dev->id.vendor. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio: indirect ring entries (VIRTIO_RING_F_INDIRECT_DESC)Mark McLoughlin
Add a new feature flag for indirect ring entries. These are ring entries which point to a table of buffer descriptors. The idea here is to increase the ring capacity by allowing a larger effective ring size whereby the ring size dictates the number of requests that may be outstanding, rather than the size of those requests. This should be most effective in the case of block I/O where we can potentially benefit by concurrently dispatching a large number of large requests. Even in the simple case of single segment block requests, this results in a threefold increase in ring capacity. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio: expose features in sysfsRusty Russell
Each device negotiates feature bits; expose these in sysfs to help diagnostics and debugging. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio_pci: optional MSI-X supportMichael S. Tsirkin
This implements optional MSI-X support in virtio_pci. MSI-X is used whenever the host supports at least 2 MSI-X vectors: 1 for configuration changes and 1 for virtqueues. Per-virtqueue vectors are allocated if enough vectors available. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (+ whitespace, style)
2009-06-12virtio_pci: split up vp_interruptMichael S. Tsirkin
This reorganizes virtio-pci code in vp_interrupt slightly, so that it's easier to add per-vq MSI support on top. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio: find_vqs/del_vqs virtio operationsMichael S. Tsirkin
This replaces find_vq/del_vq with find_vqs/del_vqs virtio operations, and updates all drivers. This is needed for MSI support, because MSI needs to know the total number of vectors upfront. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (+ lguest/9p compile fixes)
2009-06-12virtio: add names to virtqueue struct, mapping from devices to queues.Rusty Russell
Add a linked list of all virtqueues for a virtio device: this helps for debugging and is also needed for upcoming interface change. Also, add a "name" field for clearer debug messages. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12virtio: meet virtio spec by finalizing features before using deviceRusty Russell
Virtio devices are supposed to negotiate features before they start using the device, but the current code doesn't do this. This is because the driver's probe() function invariably has to add buffers to a virtqueue, or probe the disk (virtio_blk). This currently doesn't matter since no existing backend is strict about the feature negotiation. But it's possible to imagine a future feature which completely changes how a device operates: in this case, we'd need to acknowledge it before using the device. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-04-19virtio: fix suspend when using virtio_balloonMarcelo Tosatti
Break out of wait_event_interruptible() if freezing has been requested, in the vballoon thread. Without this change vballoon refuses to stop and the system can't suspend. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
2009-03-30virtio: more neatening of virtio_ring macros.Rusty Russell
Impact: cleanup Roel Kluin drew attention to these macros with his patch: here I neaten them a little further: 1) Add a comment on what START_USE and END_USE are checking, 2) Brackets around _vq in BAD_RING, 3) Neaten formatting for START_USE so it's less than 80 cols. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-03-30virtio: fix BAD_RING, START_US and END_USE macrosRoel Kluin
Impact: cleanup fix BAD_RING, START_US and END_USE macros When these macros aren't called with a variable named vq as first argument, this would result in a build failure. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-02-02virtio-pci: do not oops on config change if driver not loadedMark McLoughlin
The host really shouldn't be notifying us of config changes before the device status is VIRTIO_CONFIG_S_DRIVER or VIRTIO_CONFIG_S_DRIVER_OK. However, if we do happen to be interrupted while we're not attached to a driver, we really shouldn't oops. Prevent this simply by checking that device->driver is non-NULL before trying to notify the driver of config changes. Problem observed by doing a "set_link virtio.0 down" with QEMU before the net driver had been loaded. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06virtio: do not statically allocate root deviceMark McLoughlin
We shouldn't be statically allocating the root device object, so dynamically allocate it using root_device_register() instead. Also avoids this warning from 'rmmod virtio_pci': Device 'virtio-pci' does not have a release() function, it is broken and must be fixed Signed-off-by: Mark McLoughlin <markmc@redhat.com> Cc: Anthony Liguori <aliguori@us.ibm.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-12-30virtio: add PCI device release() functionMark McLoughlin
Add a release() function for virtio_pci devices so as to avoid: Device 'virtio0' does not have a release() function, it is broken and must be fixed Move the code to free the resources associated with the device from virtio_pci_remove() into this new function. virtio_pci_remove() now merely unregisters the device which should cause the final ref to be dropped and virtio_pci_release_dev() to be called. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Reported-by: Michael Tokarev <mjt@tls.msk.ru> Cc: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-12-30virtio: avoid implicit use of Linux page size in balloon interfaceHollis Blanchard
Make the balloon interface always use 4K pages, and convert Linux pfns if necessary. This patch assumes that Linux's PAGE_SHIFT will never be less than 12. Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (modified)
2008-12-30virtio: hand virtio ring alignment as argument to vring_new_virtqueueRusty Russell
This allows each virtio user to hand in the alignment appropriate to their virtio_ring structures. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
2008-12-30virtio: Don't use PAGE_SIZE for vring alignment in virtio_pci.Rusty Russell
That doesn't work for non-4k guests which are now appearing. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-12-30virtio: Don't use PAGE_SIZE in virtio_pci.cRusty Russell
The virtio PCI devices don't depend on the guest page size. This matters now PowerPC virtio is gaining ground (they like 64k pages). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-12-30virtio: struct device - replace bus_id with dev_name(), dev_set_name()Kay Sievers
This patch is part of a larger patch series which will remove the "char bus_id[20]" name string from struct device. The device name is managed in the kobject anyway, and without any size limitation, and just needlessly copied into "struct device". To set and read the device name dev_name(dev) and dev_set_name(dev) must be used. If your code uses static kobjects, which it shouldn't do, "const char *init_name" can be used to statically provide the name the registered device should have. At registration time, the init_name field is cleared, to enforce the use of dev_name(dev) to access the device name at a later time. We need to get rid of all occurrences of bus_id in the entire tree to be able to enable the new interface. Please apply this patch, and possibly convert any remaining remaining occurrences of bus_id. We want to submit a patch to -next, which will remove bus_id from "struct device", to find the remaining pieces to convert, and finally switch over to the new api, which will remove the 20 bytes array and does no longer have a size limitation. Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-12-30virtio-pci queue allocation not page-alignedHollis Blanchard
kzalloc() does not guarantee page alignment, and in fact this broke when I enabled CONFIG_SLUB_DEBUG_ON. (Thanks to Anthony Liguori for spotting the missing kfree sub) Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (fixed kfree) Tested-by: Anthony Liguori <aliguori@us.ibm.com>
2008-08-26virtio_balloon: fix towards_target when deflating balloonAnthony Liguori
Both v and vb->num_pages are u32 and unsigned int respectively. If v is less than vb->num_pages (and it is, when deflating the balloon), the result is a very large 32-bit number. Since we're returning a s64, instead of getting the same negative number we desire, we get a very large positive number. This handles the case where v < vb->num_pages and ensures we get a small, negative, s64 as the result. Rusty: please push this for 2.6.27-rc4. It's probably appropriate for the stable tree too as it will cause an unexpected OOM when ballooning. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (simplified)
2008-07-25virtio: Add transport feature handling stub for virtio_ring.Rusty Russell
To prepare for virtio_ring transport feature bits, hook in a call in all the users to manipulate them. This currently just clears all the bits, since it doesn't understand any features. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-25virtio: Rename set_features to finalize_featuresRusty Russell
Rather than explicitly handing the features to the lower-level, we just hand the virtio_device and have it set the features. This make it clear that it has the chance to manipulate the features of the device at this point (and that all feature negotiation is already done). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-25virtio: Formally reserve bits 28-31 to be 'transport' features.Rusty Russell
We assign feature bits as required, but it makes sense to reserve some for the particular transport, rather than the particular device. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-25virtio: Use bus_type probe and remove methodsMark McLoughlin
Hook up to the probe() and remove() methods in bus_type rather than device_driver. The latter has been preferred since 2.6.16. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>