similar to: [PATCH 5/6] virtio_blk: set QUEUE_ORDERED_DRAIN by default

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 at de.ibm.com> --- drivers/block/virtio_blk.c | 6 +++++-

This allows more requests to fit in the descriptor ring. Copying 1.7M kernel image 100 times (with sync between) Before: totsegs = 55661 totlen = 148859962 avg. 2674 After: totsegs = 36097 totlen = 139439355 avg: 3862 Unfortunately, this coalescing is done at blk_rq_map_sg() which is too late to be optimal: requests have already been limited to the value set by blk_queue_max_hw_segments().

This allows more requests to fit in the descriptor ring. Copying 1.7M kernel image 100 times (with sync between) Before: totsegs = 55661 totlen = 148859962 avg. 2674 After: totsegs = 36097 totlen = 139439355 avg: 3862 Unfortunately, this coalescing is done at blk_rq_map_sg() which is too late to be optimal: requests have already been limited to the value set by blk_queue_max_hw_segments().

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> ---

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> ---

From 5d85cee1fb14608b79b5b6103d8be2d90bb76ca4 Mon Sep 17 00:00:00 2001 From: Anthony Liguori <aliguori@us.ibm.com> Date: Mon, 12 Nov 2007 21:30:26 -0600 Subject: [PATCH] virtio: simplify config mechanism. 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

From 5d85cee1fb14608b79b5b6103d8be2d90bb76ca4 Mon Sep 17 00:00:00 2001 From: Anthony Liguori <aliguori@us.ibm.com> Date: Mon, 12 Nov 2007 21:30:26 -0600 Subject: [PATCH] virtio: simplify config mechanism. 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

This is fairly simple: we create a request pointing at the 1k kmalloc, then just change the type so our do_req() knows to mark it as a GET_ID for the server. Seems to work here; the only issue is that the error didn't get passed back from __blk_end_request_all to blk_execute_rq, so we set ->errors to 1 on error. Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> Cc: Jens Axboe

This is fairly simple: we create a request pointing at the 1k kmalloc, then just change the type so our do_req() knows to mark it as a GET_ID for the server. Seems to work here; the only issue is that the error didn't get passed back from __blk_end_request_all to blk_execute_rq, so we set ->errors to 1 on error. Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> Cc: Jens Axboe

Based on patch by Cornelia Huck. Note: for consistency, and to avoid sparse errors, convert all fields, even those no longer in use for virtio v1.0. Reviewed-by: Thomas Huth <thuth at linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi at linux.vnet.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst at

Based on patch by Cornelia Huck. Note: for consistency, and to avoid sparse errors, convert all fields, even those no longer in use for virtio v1.0. Reviewed-by: Thomas Huth <thuth at linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi at linux.vnet.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst at

Based on patch by Cornelia Huck. Note: for consistency, and to avoid sparse errors, convert all fields, even those no longer in use for virtio v1.0. Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- include/uapi/linux/virtio_blk.h | 15 ++++----- drivers/block/virtio_blk.c | 70

Based on patch by Cornelia Huck. Note: for consistency, and to avoid sparse errors, convert all fields, even those no longer in use for virtio v1.0. Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- include/uapi/linux/virtio_blk.h | 15 ++++----- drivers/block/virtio_blk.c | 70

Based on patch by Cornelia Huck. Note: for consistency, and to avoid sparse errors, convert all fields, even those no longer in use for virtio v1.0. Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- include/uapi/linux/virtio_blk.h | 15 ++++----- drivers/block/virtio_blk.c | 70

Based on patch by Cornelia Huck. Note: for consistency, and to avoid sparse errors, convert all fields, even those no longer in use for virtio v1.0. Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- include/uapi/linux/virtio_blk.h | 15 ++++----- drivers/block/virtio_blk.c | 70

Based on patch by Cornelia Huck. Note: for consistency, and to avoid sparse errors, convert all fields, even those no longer in use for virtio v1.0. Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- include/uapi/linux/virtio_blk.h | 15 ++++----- drivers/block/virtio_blk.c | 70

Based on patch by Cornelia Huck. Note: for consistency, and to avoid sparse errors, convert all fields, even those no longer in use for virtio v1.0. Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- include/uapi/linux/virtio_blk.h | 15 ++++----- drivers/block/virtio_blk.c | 70

Based on patch by Cornelia Huck. Note: for consistency, and to avoid sparse errors, convert all fields, even those no longer in use for virtio v1.0. Reviewed-by: Thomas Huth <thuth at linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi at linux.vnet.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst at

Based on patch by Cornelia Huck. Note: for consistency, and to avoid sparse errors, convert all fields, even those no longer in use for virtio v1.0. Reviewed-by: Thomas Huth <thuth at linux.vnet.ibm.com> Reviewed-by: David Hildenbrand <dahi at linux.vnet.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> Signed-off-by: Michael S. Tsirkin <mst at

Rusty, Jens, I need your opinion on the following patch. It seems to work, but I would like to get some feedback if this patch is the right approach: --- 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 device). Lets add a