similar to: [PULL] vhost: cleanups and fixes

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> ---

Though there is a problem in this setup. The end-user and hosting provider have signed SLA agreement in which some amount of memory is guaranted for the guest. The good thing is that this memory will be given to the guest when the guest will really need it (f.e. with OOM in guest and with VIRTIO_BALLOON_F_DEFLATE_ON_OOM configuration flag set). The bad thing is that end-user does not know this.

Though there is a problem in this setup. The end-user and hosting provider have signed SLA agreement in which some amount of memory is guaranted for the guest. The good thing is that this memory will be given to the guest when the guest will really need it (f.e. with OOM in guest and with VIRTIO_BALLOON_F_DEFLATE_ON_OOM configuration flag set). The bad thing is that end-user does not know this.

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 +++---

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. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- I'm inclined to merge it for the current kernel - safe and avoids confusion. 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. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- I'm inclined to merge it for the current kernel - safe and avoids confusion. include/uapi/linux/virtio_blk.h | 6 +++---

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

The following changes since commit 997e120843e82609c8d99a9d5714e6cf91e14cbe: virtio_balloon: do not change memory amount visible via /proc/meminfo (2015-09-08 13:32:11 +0300) are available in the git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git tags/for_linus for you to fetch changes up to ad2aa04218de9bd734d593adb0ac59854ec0cb68: virtio/s390: handle

The following changes since commit 997e120843e82609c8d99a9d5714e6cf91e14cbe: virtio_balloon: do not change memory amount visible via /proc/meminfo (2015-09-08 13:32:11 +0300) are available in the git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git tags/for_linus for you to fetch changes up to ad2aa04218de9bd734d593adb0ac59854ec0cb68: virtio/s390: handle

Current virtio-blk spec only supports one virtual queue for transfering data between VM and host, and inside VM all kinds of operations on the virtual queue needs to hold one lock, so cause below problems: - no scalability - bad throughput So this patch requests to introduce feature of VIRTIO_BLK_F_MQ so that more than one virtual queues can be used to virtio-blk device, then above problems

Current virtio-blk spec only supports one virtual queue for transfering data between VM and host, and inside VM all kinds of operations on the virtual queue needs to hold one lock, so cause below problems: - bad scalability - bad throughput This patch requests to introduce feature of VIRTIO_BLK_F_MQ so that more than one virtual queues can be used to virtio-blk device, then above problems can

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

Add a helper function for checking whether a bit is set in the guest features for a vdev as well as one that works on a feature bit set. Convert code that open-coded this: It cleans up the code and makes it easier to extend the guest feature bits. Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> --- hw/block/virtio-blk.c | 7 ++----- hw/char/virtio-serial-bus.c | 2

Add a helper function for checking whether a bit is set in the guest features for a vdev as well as one that works on a feature bit set. Convert code that open-coded this: It cleans up the code and makes it easier to extend the guest feature bits. Signed-off-by: Cornelia Huck <cornelia.huck at de.ibm.com> --- hw/block/virtio-blk.c | 7 ++----- hw/char/virtio-serial-bus.c | 2

On Tue, Feb 23, 2016 at 06:26:47PM +0300, Denis V. Lunev wrote: > On 02/23/2016 06:10 PM, Michael S. Tsirkin wrote: > >On Tue, Feb 16, 2016 at 06:50:52PM +0300, Denis V. Lunev wrote: > >>From: Igor Redko <redkoi at virtuozzo.com> > >> > >>Add a new field, VIRTIO_BALLOON_S_AVAIL, to virtio_balloon memory > >>statistics protocol, corresponding to

On Tue, Feb 23, 2016 at 06:26:47PM +0300, Denis V. Lunev wrote: > On 02/23/2016 06:10 PM, Michael S. Tsirkin wrote: > >On Tue, Feb 16, 2016 at 06:50:52PM +0300, Denis V. Lunev wrote: > >>From: Igor Redko <redkoi at virtuozzo.com> > >> > >>Add a new field, VIRTIO_BALLOON_S_AVAIL, to virtio_balloon memory > >>statistics protocol, corresponding to