Re: [Qemu-devel] [RFC 25/29] vhu: enable = false on get_vring_base

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Michael S. Tsirkin (mst@redhat.com) wrote:
> On Wed, Jun 28, 2017 at 08:00:43PM +0100, Dr. David Alan Gilbert (git) wrote:
> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> > 
> > When we receive a GET_VRING_BASE message set enable = false
> > to stop any new received packets modifying the ring.
> > 
> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> 
> I think I already reviewed a similar patch.
> Spec says:
> Client must only process each ring when it is started.
> 
> IMHO the real fix is to fix client to check the started
> flag before processing the ring.

Done, I added a vu_queue_started to match vu_queue_enabled
and then used it.

Dave

> > ---
> >  contrib/libvhost-user/libvhost-user.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
> > index ceddeac74f..d37052b7b0 100644
> > --- a/contrib/libvhost-user/libvhost-user.c
> > +++ b/contrib/libvhost-user/libvhost-user.c
> > @@ -652,6 +652,7 @@ vu_get_vring_base_exec(VuDev *dev, VhostUserMsg *vmsg)
> >      vmsg->size = sizeof(vmsg->payload.state);
> >  
> >      dev->vq[index].started = false;
> > +    dev->vq[index].enable = false;
> >      if (dev->iface->queue_set_started) {
> >          dev->iface->queue_set_started(dev, index, false);
> >      }
> > -- 
> > 2.13.0
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK