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path: root/drivers/block/virtio_blk.c
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2008-07-25virtio_blk: check for hardsector size from hostChristian Borntraeger
Currently virtio_blk assumes a 512 byte hard sector size. This can cause trouble / performance issues if the backing has a different block size (like a file on an ext3 file system formatted with 4k block size or a dasd). Lets add a feature flag that tells the guest to use a different hard sector size than 512 byte. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-05-30virtio_blk: allow read-only disksChristian Borntraeger
Hello Rusty, sometimes it is useful to share a disk (e.g. usr). To avoid file system corruption, the disk should be mounted read-only in that case. This patch adds a new feature flag, that allows the host to specify, if the disk should be considered read-only. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-05-30Fix crash in virtio_blk during modprobe ; rmmod ; modprobeChris Lalancette
Fix a modprobe virtio_blk ; rmmod virtio_blk ; modprobe virtio_blk crash; this was basically because we weren't doing "del_gendisk()" in the remove path. Signed-off-by: Chris Lalancette <clalance@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (moved del_gendisk up)
2008-05-02virtio: add virtio disk geometry featureRyan Harper
Rather than faking up some geometry, allow the backend to push the disk geometry via virtio pci config option. Keep the old geo code around for compatibility. Signed-off-by: Ryan Harper <ryanh@us.ibm.com> Reviewed-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (modified to single struct)
2008-05-02virtio: explicit advertisement of driver featuresRusty Russell
A recent proposed feature addition to the virtio block driver revealed some flaws in the API: in particular, we assume that feature negotiation is complete once a driver's probe function returns. There is nothing in the API to require this, however, and even I didn't notice when it was violated. So instead, we require the driver to specify what features it supports in a table, we can then move the feature negotiation into the virtio core. The intersection of device and driver features are presented in a new 'features' bitmap in the struct virtio_device. Note that this highlights the difference between Linux unsigned-long bitmaps where each unsigned long is in native endian, and a straight-forward little-endian array of bytes. Drivers can still remove feature bits in their probe routine if they really have to. API changes: - dev->config->feature() no longer gets and acks a feature. - drivers should advertise their features in the 'feature_table' field - use virtio_has_feature() for extra sanity when checking feature bits Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-05-02virtio: change config to guest endian.Rusty Russell
A recent proposed feature addition to the virtio block driver revealed some flaws in the API, in particular how easy it is to break big endian machines. The virtio config space was originally chosen to be little-endian, because we thought the config might be part of the PCI config space for virtio_pci. It's actually a separate mmio region, so that argument holds little water; as only x86 is currently using the virtio mechanism, we can change this (but must do so now, before the impending s390 merge). API changes: - __virtio_config_val() just becomes a striaght vdev->config_get() call. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-05-02virtio-blk: fix remove oopsMarcelo Tosatti
Do not unregister the major at device remove, since there might be another device instances around. (qemu) pci_del 0 11 (qemu) ACPI: PCI interrupt for device 0000:00:0b.0 disabled (qemu) pci_del 0 10 (qemu) ------------[ cut here ]------------ WARNING: at block/genhd.c:126 unregister_blkdev+0x74/0x9e() ACPI: PCI interrupt for device 0000:00:0a.0 disabled Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-05-02virtio: de-structify virtio_block status byteRusty Russell
Ron Minnich points out that a struct containing a char is not always sizeof(char); simplest to remove the structure to avoid confusion. Cc: "ron minnich" <rminnich@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-03-17virtio: Fix sysfs bits to have proper block symlinkJeremy Katz
Fix up so that the virtio_blk devices in sysfs link correctly to their block device. This then allows them to be detected by hal, etc Signed-off-by: Jeremy Katz <katzj@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-02-04virtio_blk: implement naming for vda-vdz,vdaa-vdzz,vdaaa-vdzzzChristian Borntraeger
Am Freitag, 1. Februar 2008 schrieb Christian Borntraeger: > Right. I will fix that with an additional patch. This patch goes on top of the minor number patch. Please let me know if you want a merged patch: Currently virtio_blk creates the disk name combinging "vd" with 'a'++. This will give strange names after vdz. I have implemented names up to vdzzz - inspired by the sd.c code. That should be sufficient for now. There is one driver in the kernel (driver/s390/block/dasd_genhd.c) that implements names from dasda-dasdzzzz allowing even more disks. Maybe a janitor can come up with a common implementation usable for all kind of block device drivers. I have tested this patch with 100 disks - seems to work. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-02-04virtio_blk: Dont waste major numbersChristian Borntraeger
Rusty, currently virtio_blk uses one major number per device. While this works quite well on most systems it is wasteful and will exhaust major numbers on larger installations. This patch allocates a major number on init and will use 16 minor numbers for each disk. That will allow ~64k virtio_blk disks. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-02-04virtio_blk: provide getgeoChristian Borntraeger
Rusty, I currently try to make my guest boot from an virtio root device without having an external kernel. Some of the tools that I tried expect HDIO_GETGEO to work. The most interesting value is likely the geo.start value to get the offset of a partition. This value is filled by block/ioctl.c if fops->getgeo is set. This patch also fills in some standard values for heads, sectors and cylinders. Makes sense? Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-02-04virtio: reset functionRusty Russell
A reset function solves three problems: 1) It allows us to renegotiate features, eg. if we want to upgrade a guest driver without rebooting the guest. 2) It gives us a clean way of shutting down virtqueues: after a reset, we know that the buffers won't be used by the host, and 3) It helps the guest recover from messed-up drivers. So we remove the ->shutdown hook, and the only way we now remove feature bits is via reset. We leave it to the driver to do the reset before it deletes queues: the balloon driver, for example, needs to chat to the host in its remove function. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-02-04virtio: explicit enable_cb/disable_cb rather than callback return.Rusty Russell
It seems that virtio_net wants to disable callbacks (interrupts) before calling netif_rx_schedule(), so we can't use the return value to do so. Rename "restart" to "cb_enable" and introduce "cb_disable" hook: callback now returns void, rather than a boolean. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-02-04virtio: simplify config mechanism.Rusty Russell
Previously we used a type/len pair within the config space, but this seems overkill. We now simply define a structure which represents the layout in the config space: the config space can now only be extended at the end. The main driver-visible changes: 1) We indicate what fields are present with an explicit feature bit. 2) Virtqueues are explicitly numbered, and not in the config space. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-11-19virtio: fix module/device unloadingRusty Russell
The virtio code never hooked through the ->remove callback. Although noone supports device removal at the moment, this code is already needed for module unloading. This of course also revealed bugs in virtio_blk, virtio_net and lguest unloading paths. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-24SG: audit of drivers that use blk_rq_map_sg()Jens Axboe
They need to properly init the sg table, or blk_rq_map_sg() will complain if CONFIG_DEBUG_SG is set. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-23Block driver using virtio.Rusty Russell
The block driver uses scatter-gather lists with sg[0] being the request information (struct virtio_blk_outhdr) with the type, sector and inbuf id. The next N sg entries are the bio itself, then the last sg is the status byte. Whether the N entries are in or out depends on whether it's a read or a write. We accept the normal (SCSI) ioctls: they get handed through to the other side which can then handle it or reply that it's unsupported. It's not clear that this actually works in general, since I don't know if blk_pc_request() requests have an accurate rq_data_dir(). Although we try to reply -ENOTTY on unsupported commands, ioctl(fd, CDROMEJECT) returns success to userspace. This needs a separate patch. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <jens.axboe@oracle.com>