[PATCH v3 3/4] vhost: fix invalid call FD handling

[Xia, Chenbo]

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin at redhat.com>
> Sent: Tuesday, May 30, 2023 8:54 PM
> To: Eelco Chaudron <echaudro at redhat.com>; Xia, Chenbo
> <chenbo.xia at intel.com>; david.marchand at redhat.com
> Cc: dev at dpdk.org
> Subject: Re: [PATCH v3 3/4] vhost: fix invalid call FD handling
> 
> 
> 
> On 5/17/23 11:09, Eelco Chaudron wrote:
> > This patch fixes cases where IRQ injection is tried while
> > the call FD is not valid, which should not happen.
> >
> > Fixes: b1cce26af1dc ("vhost: add notification for packed ring")
> > Fixes: e37ff954405a ("vhost: support virtqueue interrupt/notification
> suppression")
> >
> > Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
> > Signed-off-by: Eelco Chaudron <echaudro at redhat.com>
> > ---
> >   lib/vhost/vhost.h |    8 ++++----
> >   1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
> > index 37609c7c8d..23a4e2b1a7 100644
> > --- a/lib/vhost/vhost.h
> > +++ b/lib/vhost/vhost.h
> > @@ -903,9 +903,9 @@ vhost_vring_call_split(struct virtio_net *dev,
> struct vhost_virtqueue *vq)
> >   			"%s: used_event_idx=%d, old=%d, new=%d\n",
> >   			__func__, vhost_used_event(vq), old, new);
> >
> > -		if ((vhost_need_event(vhost_used_event(vq), new, old) &&
> > -					(vq->callfd >= 0)) ||
> > -				unlikely(!signalled_used_valid)) {
> > +		if ((vhost_need_event(vhost_used_event(vq), new, old) ||
> > +					unlikely(!signalled_used_valid)) &&
> > +				vq->callfd >= 0) {
> >   			eventfd_write(vq->callfd, (eventfd_t) 1);
> >   			if (dev->flags & VIRTIO_DEV_STATS_ENABLED)
> >   				__atomic_fetch_add(&vq->stats.guest_notifications,
> > @@ -974,7 +974,7 @@ vhost_vring_call_packed(struct virtio_net *dev,
> struct vhost_virtqueue *vq)
> >   	if (vhost_need_event(off, new, old))
> >   		kick = true;
> >   kick:
> > -	if (kick) {
> > +	if (kick && vq->callfd >= 0) {
> >   		eventfd_write(vq->callfd, (eventfd_t)1);
> >   		if (dev->notify_ops->guest_notified)
> >   			dev->notify_ops->guest_notified(dev->vid);
> >
> 
> Reporting Chenbo's R-by, from the VDUSE series RFC:
> 
> Reviewed-by: Chenbo Xia <chenbo.xia at intel.com>

Thanks Maxime! Btw: what's your plan of the same fix in VDUSE series, do you plan
to drop it in VDUSE series or?

Thanks,
Chenbo