search for: vhost_notifi

This reverts commit 809ecb9bca6a9424ccd392d67e368160f8b76c92. Since it was reported to break vhost_net. We want to cache used event and use it to check for notification. The assumption was that guest won't move the event idx back, but this could happen in fact when 16 bit index wraps around after 64K entries. Signed-off-by: Jason Wang <jasowang at redhat.com> --- - Changes from V1:

This reverts commit 809ecb9bca6a9424ccd392d67e368160f8b76c92. Since it was reported to break vhost_net. We want to cache used event and use it to check for notification. The assumption was that guest won't move the event idx back, but this could happen in fact when 16 bit index wraps around after 64K entries. Signed-off-by: Jason Wang <jasowang at redhat.com> --- - Changes from V1:

This reverts commit 809ecb9bca6a9424ccd392d67e368160f8b76c92. Since it was reported to break vhost_net. We want to cache used event and use it to check for notification. We try to valid cached used event by checking whether or not it was ahead of new, but this is not correct all the time, it could be stale and there's no way to know about this. Signed-off-by: Jason Wang <jasowang at

This reverts commit 809ecb9bca6a9424ccd392d67e368160f8b76c92. Since it was reported to break vhost_net. We want to cache used event and use it to check for notification. We try to valid cached used event by checking whether or not it was ahead of new, but this is not correct all the time, it could be stale and there's no way to know about this. Signed-off-by: Jason Wang <jasowang at

On 2020/8/4 ??4:42, Zhu, Lingshan wrote: > > > On 8/4/2020 4:38 PM, Jason Wang wrote: >> >> On 2020/7/31 ??2:55, Zhu Lingshan wrote: >>> This commit introduces struct vhost_vring_call which replaced >>> raw struct eventfd_ctx *call_ctx in struct vhost_virtqueue. >>> Besides eventfd_ctx, it contains a spin lock and an >>> irq_bypass_producer

On 2020/8/4 ??4:42, Zhu, Lingshan wrote: > > > On 8/4/2020 4:38 PM, Jason Wang wrote: >> >> On 2020/7/31 ??2:55, Zhu Lingshan wrote: >>> This commit introduces struct vhost_vring_call which replaced >>> raw struct eventfd_ctx *call_ctx in struct vhost_virtqueue. >>> Besides eventfd_ctx, it contains a spin lock and an >>> irq_bypass_producer

When event index was enabled, we need to fetch used event from userspace memory each time. This userspace fetch (with memory barrier) could be saved sometime when 1) caching used event and 2) if used event is ahead of new and old to new updating does not cross it, we're sure there's no need to notify guest. This will be useful for heavy tx load e.g guest pktgen test with Linux driver

When event index was enabled, we need to fetch used event from userspace memory each time. This userspace fetch (with memory barrier) could be saved sometime when 1) caching used event and 2) if used event is ahead of new and old to new updating does not cross it, we're sure there's no need to notify guest. This will be useful for heavy tx load e.g guest pktgen test with Linux driver

On Wed, Jul 26, 2017 at 04:03:17PM +0800, Jason Wang wrote: > This reverts commit 809ecb9bca6a9424ccd392d67e368160f8b76c92. Since it > was reported to break vhost_net. We want to cache used event and use > it to check for notification. We try to valid cached used event by > checking whether or not it was ahead of new, but this is not correct > all the time, it could be stale and

On 2020/7/31 ??2:55, Zhu Lingshan wrote: > This commit introduces struct vhost_vring_call which replaced > raw struct eventfd_ctx *call_ctx in struct vhost_virtqueue. > Besides eventfd_ctx, it contains a spin lock and an > irq_bypass_producer in its structure. > > Signed-off-by: Zhu Lingshan <lingshan.zhu at intel.com> > Suggested-by: Jason Wang <jasowang at

On 2020/7/16 ??7:23, Zhu Lingshan wrote: > This commit introduces struct vhost_call_ctx which replaced > raw struct eventfd_ctx *call_ctx in struct vhost_virtqueue. > Besides eventfd_ctx, it contains a spin lock and an > irq_bypass_producer in its structure. > > Signed-off-by: Zhu Lingshan <lingshan.zhu at intel.com> > Suggested-by: Jason Wang <jasowang at

Please ignore this patchset incorrect metadata, will resend soon. Thanks! On 7/22/2020 5:49 PM, Zhu Lingshan wrote: > From: Zhu Lingshan <lingshan.zhu at intel.com> > > This commit introduces struct vhost_vring_call which replaced > raw struct eventfd_ctx *call_ctx in struct vhost_virtqueue. > Besides eventfd_ctx, it contains a spin lock and an > irq_bypass_producer in its

On Tue, Aug 04, 2020 at 04:53:39PM +0800, Jason Wang wrote: > > On 2020/8/4 ??4:42, Zhu, Lingshan wrote: > > > > > > On 8/4/2020 4:38 PM, Jason Wang wrote: > > > > > > On 2020/7/31 ??2:55, Zhu Lingshan wrote: > > > > This commit introduces struct vhost_vring_call which replaced > > > > raw struct eventfd_ctx *call_ctx in struct

Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/vhost/vhost.c | 93 +++++++++++++++++++++++++++++++-------------------- 1 file changed, 56 insertions(+), 37 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index c90f437..4d379ed 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -33,8 +33,8 @@ enum { VHOST_MEMORY_F_LOG = 0x1, };

Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/vhost/vhost.c | 93 +++++++++++++++++++++++++++++++-------------------- 1 file changed, 56 insertions(+), 37 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index c90f437..4d379ed 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -33,8 +33,8 @@ enum { VHOST_MEMORY_F_LOG = 0x1, };

Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/vhost/vhost.c | 93 +++++++++++++++++++++++++++++++-------------------- 1 file changed, 56 insertions(+), 37 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index c90f437..4d379ed 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -33,8 +33,8 @@ enum { VHOST_MEMORY_F_LOG = 0x1, };

Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/vhost/vhost.c | 93 +++++++++++++++++++++++++++++++-------------------- 1 file changed, 56 insertions(+), 37 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index c90f437..4d379ed 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -33,8 +33,8 @@ enum { VHOST_MEMORY_F_LOG = 0x1, };

This patch introduces basic support for event suppression aka driver and device area. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/vhost/vhost.c | 168 ++++++++++++++++++++++++++++++++++++--- drivers/vhost/vhost.h | 10 ++- include/uapi/linux/virtio_ring.h | 19 +++++ 3 files changed, 182 insertions(+), 15 deletions(-) diff --git

On 2020/6/4 ??5:03, Michael S. Tsirkin wrote: >>> static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq) >>> { >>> __u16 old, new; >>> diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h >>> index a67bda9792ec..6c10e99ff334 100644 >>> --- a/drivers/vhost/vhost.h >>> +++ b/drivers/vhost/vhost.h

This patch introduces basic support for event suppression aka driver and device area. Compile tested only. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/vhost/vhost.c | 169 ++++++++++++++++++++++++++++++++++++--- drivers/vhost/vhost.h | 10 ++- include/uapi/linux/virtio_ring.h | 19 +++++ 3 files changed, 183 insertions(+), 15 deletions(-) diff