similar to: [PATCH] virtio_blk: VIRTIO_BLK_F_WCE->VIRTIO_BLK_F_FLUSH

Latest virtio spec says the feature bit name is VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_WCE is the legacy name. virtio blk header says exactly the reverse - fix that and update driver code to match. Cc: Paolo Bonzini <pbonzini at redhat.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- Changs from v1: comments updated include/uapi/linux/virtio_blk.h | 6 +++---

Latest virtio spec says the feature bit name is VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_WCE is the legacy name. virtio blk header says exactly the reverse - fix that and update driver code to match. Cc: Paolo Bonzini <pbonzini at redhat.com> Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- Changs from v1: comments updated include/uapi/linux/virtio_blk.h | 6 +++---

VIRTIO_BLK_F_CONFIG_WCE is important in order to achieve good performance (up to 2x, though more realistically +30-40%) in latency-bound workloads. However, it was removed by mistake together with VIRTIO_BLK_F_FLUSH. It will be restored in the next revision of the virtio 1.0 standard, so do the same in Linux. Signed-off-by: Paolo Bonzini <pbonzini at redhat.com> ---

VIRTIO_BLK_F_CONFIG_WCE is important in order to achieve good performance (up to 2x, though more realistically +30-40%) in latency-bound workloads. However, it was removed by mistake together with VIRTIO_BLK_F_FLUSH. It will be restored in the next revision of the virtio 1.0 standard, so do the same in Linux. Signed-off-by: Paolo Bonzini <pbonzini at redhat.com> ---

Currently virtio-blk driver does not provide discard feature flag, so the filesystems which built on top of the block device will not send discard command. This is okay for HDD backend, but it will impact the performance for SSD backend. Add a feature flag VIRTIO_BLK_F_DISCARD and command VIRTIO_BLK_T_DISCARD to extend exist virtio-blk protocol, define 16 bytes discard descriptor for each discard

Currently virtio-blk driver does not provide discard feature flag, so the filesystems which built on top of the block device will not send discard command. This is okay for HDD backend, but it will impact the performance for SSD backend. Add a feature flag VIRTIO_BLK_F_DISCARD and command VIRTIO_BLK_T_DISCARD to extend exist virtio-blk protocol, define 16 bytes discard descriptor for each discard

Currently virtio-blk driver does not provide discard feature flag, so the filesystems which built on top of the block device will not send discard command. This is okay for HDD backend, but it will impact the performance for SSD backend. Add a feature flag VIRTIO_BLK_F_DISCARD and command VIRTIO_BLK_T_DISCARD to extend exist virtio-blk protocol. virtio-blk protocol uses a single 8 bytes

Currently virtio-blk driver does not provide discard feature flag, so the filesystems which built on top of the block device will not send discard command. This is okay for HDD backend, but it will impact the performance for SSD backend. Add a feature flag VIRTIO_BLK_F_DISCARD and command VIRTIO_BLK_T_DISCARD to extend exist virtio-blk protocol. virtio-blk protocol uses a single 8 bytes

On Tue, Jul 03, 2012 at 03:19:37PM +0200, Paolo Bonzini wrote: > This patch adds support for the new VIRTIO_BLK_F_CONFIG_WCE feature, > which exposes the cache mode in the configuration space and lets the > driver modify it. The cache mode is exposed via sysfs. > > Even if the host does not support the new feature, the cache mode is > visible (thanks to the existing

On Tue, Jul 03, 2012 at 03:19:37PM +0200, Paolo Bonzini wrote: > This patch adds support for the new VIRTIO_BLK_F_CONFIG_WCE feature, > which exposes the cache mode in the configuration space and lets the > driver modify it. The cache mode is exposed via sysfs. > > Even if the host does not support the new feature, the cache mode is > visible (thanks to the existing

> -----Original Message----- > From: Stefan Hajnoczi [mailto:stefanha at gmail.com] > Sent: Tuesday, March 28, 2017 4:20 AM > To: Liu, Changpeng <changpeng.liu at intel.com> > Cc: virtio-dev at lists.oasis-open.org; virtualization at lists.linux-foundation.org; linux- > kernel at vger.kernel.org; hch at lst.de; qemu-devel at nongnu.org > Subject: Re: [PATCH] virtio-blk:

> -----Original Message----- > From: Stefan Hajnoczi [mailto:stefanha at gmail.com] > Sent: Tuesday, March 28, 2017 4:20 AM > To: Liu, Changpeng <changpeng.liu at intel.com> > Cc: virtio-dev at lists.oasis-open.org; virtualization at lists.linux-foundation.org; linux- > kernel at vger.kernel.org; hch at lst.de; qemu-devel at nongnu.org > Subject: Re: [PATCH] virtio-blk:

Existing virtio-blk protocol doesn't have DISCARD/WRITE ZEROES command support, this will impact the performance when using SSD backend over file systems. The idea here is using 16 Bytes payload as one descriptor for DISCARD/WRITE ZEROES command, users can put several ranges into one command, for the purpose to support such feature, two feature flags

Existing virtio-blk protocol doesn't have DISCARD/WRITE ZEROES command support, this will impact the performance when using SSD backend over file systems. The idea here is using 16 Bytes payload as one descriptor for DISCARD/WRITE ZEROES command, users can put several ranges into one command, for the purpose to support such feature, two feature flags

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

On Mon, Dec 01, 2014 at 09:16:41AM +0100, David Hildenbrand wrote: > > 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.

On Mon, Dec 01, 2014 at 09:16:41AM +0100, David Hildenbrand wrote: > > 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.

Existing virtio-blk protocol doesn't have DISCARD/WRITE ZEROES commands support, this will impact the performance when using SSD backend over file systems. Commit 88c85538 "virtio-blk: add discard and write zeroes features to specification"(see https://github.com/oasis-tcs/virtio-spec) extended existing virtio-blk protocol, adding extra DISCARD and WRITE ZEROES commands support.

Existing virtio-blk protocol doesn't have DISCARD/WRITE ZEROES commands support, this will impact the performance when using SSD backend over file systems. Commit 88c85538 "virtio-blk: add discard and write zeroes features to specification"(see https://github.com/oasis-tcs/virtio-spec) extended existing virtio-blk protocol, adding extra DISCARD and WRITE ZEROES commands support.