Re: [PATCH v7] vhost: support virtqueue interrupt/notification suppression

[Yuanhan Liu <yliu@fridaylinux.org>]

On Tue, Jan 09, 2018 at 07:34:17AM +0000, Yao, Lei A wrote:
> 
> 
> > -----Original Message-----
> > From: Chen, Junjie J
> > Sent: Tuesday, January 9, 2018 7:04 PM
> > To: yliu@fridaylinux.org; maxime.coquelin@redhat.com; Wang, Xiao W
> > <xiao.w.wang@intel.com>; Bie, Tiwei <tiwei.bie@intel.com>; Yao, Lei A
> > <lei.a.yao@intel.com>
> > Cc: dev@dpdk.org; Chen, Junjie J <junjie.j.chen@intel.com>
> > Subject: [PATCH v7] vhost: support virtqueue interrupt/notification
> > suppression
> > 
> > The driver can suppress interrupt when VIRTIO_F_EVENT_IDX feature bit is
> > negotiated. The driver set vring flags to 0, and MAY use used_event in
> > available ring to advise device interrupt util reach an index specified
> > by used_event. The device ignore the lower bit of vring flags, and send
> > an interrupt when index reach used_event.
> > 
> > The device can suppress notification in a manner analogous to the ways
> > driver suppress interrupt. The device manipulates flags or avail_event in
> > the used ring in the same way the driver manipulates flags or used_event in
> > available ring.
> > 
> > Signed-off-by: Junjie Chen <junjie.j.chen@intel.com>
> Tested-by: Lei Yao <lei.a.yao@intel.com>

Applied to dpdk-next-virtio.

Thanks.

	--yliu

> VM2VM Iperf test has been executed with virtio-net driver after apply this patch.
> No performance drop. 
> CPU: Intel(R) Xeon(R) CPU E5-2699 v4 @ 2.20GHz
> Host OS: Ubuntu 16.04
> Guest OS: Ubuntu 16.04
> Kernel: 4.4.0