search for: virtio_scsi_vq_base

vscsi->num_queues counts the number of request virtqueue which does not include the control and event virtqueue. It is wrong to subtract VIRTIO_SCSI_VQ_BASE from vscsi->num_queues. This patch fixes the following panic. (qemu) device_del scsi0 BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 IP: [<ffffffff8179b29f>] __virtscsi_set_affinity+0x6f/0x120 PGD 0 Oops: 0000 [#1] SMP Modules linked in: CPU: 0 PID: 659...

vscsi->num_queues counts the number of request virtqueue which does not include the control and event virtqueue. It is wrong to subtract VIRTIO_SCSI_VQ_BASE from vscsi->num_queues. This patch fixes the following panic. (qemu) device_del scsi0 BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 IP: [<ffffffff8179b29f>] __virtscsi_set_affinity+0x6f/0x120 PGD 0 Oops: 0000 [#1] SMP Modules linked in: CPU: 0 PID: 659...

This series implements virtio-scsi queue steering, which gives performance improvements of up to 50% (measured both with QEMU and tcm_vhost backends). The patches build on top of the new virtio APIs at http://permalink.gmane.org/gmane.linux.kernel.virtualization/18431; the new API simplifies the locking of the virtio-scsi driver nicely, thus it makes sense to require them as a prerequisite.

This series implements virtio-scsi queue steering, which gives performance improvements of up to 50% (measured both with QEMU and tcm_vhost backends). The patches build on top of the new virtio APIs at http://permalink.gmane.org/gmane.linux.kernel.virtualization/18431; the new API simplifies the locking of the virtio-scsi driver nicely, thus it makes sense to require them as a prerequisite.

This series implements virtio-scsi queue steering, which gives performance improvements of up to 50% (measured both with QEMU and tcm_vhost backends). This version rebased on Rusty's virtio ring rework patches. We hope this can go into virtio-next together with the virtio ring rework pathes. V5: improving the grammar of 1/5 (Paolo) move the dropping of sg_elems to 'virtio-scsi: use

This series implements virtio-scsi queue steering, which gives performance improvements of up to 50% (measured both with QEMU and tcm_vhost backends). This version rebased on Rusty's virtio ring rework patches. We hope this can go into virtio-next together with the virtio ring rework pathes. V5: improving the grammar of 1/5 (Paolo) move the dropping of sg_elems to 'virtio-scsi: use

...> Rich. We must prevent driver from submitting s/g lists > vq size to device. Either tell linux to avoid s/g lists that are too long, or simply fail request if this happens, or refuse to attach driver to device. Later option would look something like this within probe: for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) if (vqs[i]->num < MAX_SG_USED_BY_LINUX) goto err; I don't know what's MAX_SG_USED_BY_LINUX though. > -- > Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones > Read my programming and virtualization blog: http://rwmj.wo...

...> Rich. We must prevent driver from submitting s/g lists > vq size to device. Either tell linux to avoid s/g lists that are too long, or simply fail request if this happens, or refuse to attach driver to device. Later option would look something like this within probe: for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) if (vqs[i]->num < MAX_SG_USED_BY_LINUX) goto err; I don't know what's MAX_SG_USED_BY_LINUX though. > -- > Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones > Read my programming and virtualization blog: http://rwmj.wo...

This series implements virtio-scsi queue steering, which gives performance improvements of up to 50% (measured both with QEMU and tcm_vhost backends). This version rebased on Rusty's virtio ring rework patches. We hope this can go into virtio-next together with the virtio ring rework pathes. V4: rebase on virtio ring rework patches (rusty's pending-rebases branch) V3 and be found

This series implements virtio-scsi queue steering, which gives performance improvements of up to 50% (measured both with QEMU and tcm_vhost backends). This version rebased on Rusty's virtio ring rework patches. We hope this can go into virtio-next together with the virtio ring rework pathes. V4: rebase on virtio ring rework patches (rusty's pending-rebases branch) V3 and be found

This series implements virtio-scsi queue steering, which gives performance improvements of up to 50% (measured both with QEMU and tcm_vhost backends). This version rebased on Rusty's virtio ring rework patches, which has already gone into virtio-next today. We hope this can go into virtio-next together with the virtio ring rework pathes. V6: rework "redo allocation of target data"

This series implements virtio-scsi queue steering, which gives performance improvements of up to 50% (measured both with QEMU and tcm_vhost backends). This version rebased on Rusty's virtio ring rework patches, which has already gone into virtio-next today. We hope this can go into virtio-next together with the virtio ring rework pathes. V6: rework "redo allocation of target data"

Hi all, this series adds multiqueue support to the virtio-scsi driver, based on Jason Wang's work on virtio-net. It uses a simple queue steering algorithm that expects one queue per CPU. LUNs in the same target always use the same queue (so that commands are not reordered); queue switching occurs when the request being queued is the only one for the target. Also based on Jason's

Hi all, this series adds multiqueue support to the virtio-scsi driver, based on Jason Wang's work on virtio-net. It uses a simple queue steering algorithm that expects one queue per CPU. LUNs in the same target always use the same queue (so that commands are not reordered); queue switching occurs when the request being queued is the only one for the target. Also based on Jason's

This series implements virtio-scsi queue steering, which gives performance improvements of up to 50% (measured both with QEMU and tcm_vhost backends). This version rebased on Rusty's virtio ring rework patches, which has already gone into virtio-next today. We hope this can go into virtio-next together with the virtio ring rework pathes. V7: respin to fix the patch apply error V6: rework

This series implements virtio-scsi queue steering, which gives performance improvements of up to 50% (measured both with QEMU and tcm_vhost backends). This version rebased on Rusty's virtio ring rework patches, which has already gone into virtio-next today. We hope this can go into virtio-next together with the virtio ring rework pathes. V7: respin to fix the patch apply error V6: rework

Hi all, this series adds multiqueue support to the virtio-scsi driver, based on Jason Wang's work on virtio-net. It uses a simple queue steering algorithm that expects one queue per CPU. LUNs in the same target always use the same queue (so that commands are not reordered); queue switching occurs when the request being queued is the only one for the target. Also based on Jason's

Hi all, this series adds multiqueue support to the virtio-scsi driver, based on Jason Wang's work on virtio-net. It uses a simple queue steering algorithm that expects one queue per CPU. LUNs in the same target always use the same queue (so that commands are not reordered); queue switching occurs when the request being queued is the only one for the target. Also based on Jason's

On Thu, Aug 10, 2017 at 10:30:38PM +0100, Richard W.M. Jones wrote: > On Fri, Aug 11, 2017 at 12:21:16AM +0300, Michael S. Tsirkin wrote: > > On Thu, Aug 10, 2017 at 05:40:34PM +0100, Richard W.M. Jones wrote: > > > If using indirect descriptors, you can make the total_sg as large as > > > you want. > > > > That would be a spec violation though, even if it

On Thu, Aug 10, 2017 at 10:30:38PM +0100, Richard W.M. Jones wrote: > On Fri, Aug 11, 2017 at 12:21:16AM +0300, Michael S. Tsirkin wrote: > > On Thu, Aug 10, 2017 at 05:40:34PM +0100, Richard W.M. Jones wrote: > > > If using indirect descriptors, you can make the total_sg as large as > > > you want. > > > > That would be a spec violation though, even if it