Re: [Qemu-devel] [PATCH] virtio/vhost: drop unnecessary VHOST_SET_VRING call

[Marcel Apfelbaum]

On 08/12/2015 01:34 PM, Michael S. Tsirkin wrote:
> On Wed, Aug 12, 2015 at 01:19:51PM +0300, Marcel Apfelbaum wrote:
> > No need to send VHOST_SET_VRING_CALL to backend
> > before the negotiation with the guest is finished.
> >
> > Signed-off-by: Marcel Apfelbaum <address@hidden>
>
> Well - we do need to set it to the masked notifier initially to avoid
> losing events.  You can't just drop it - need to move this call
> somewhere else.
What do we need to set?
I just dropped the call to VHOST_SET_VRING_CALL.

Thanks,
Marcel

> > ---
> >   hw/virtio/vhost.c | 13 +------------
> >   1 file changed, 1 insertion(+), 12 deletions(-)
> >
> > diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> > index 2712c6f..b448542 100644
> > --- a/hw/virtio/vhost.c
> > +++ b/hw/virtio/vhost.c
> > @@ -875,24 +875,13 @@ static void vhost_eventfd_del(MemoryListener *listener,
> >   static int vhost_virtqueue_init(struct vhost_dev *dev,
> >                                   struct vhost_virtqueue *vq, int n)
> >   {
> > -    struct vhost_vring_file file = {
> > -        .index = n,
> > -    };
> >       int r = event_notifier_init(&vq->masked_notifier, 0);
> > +
> >       if (r < 0) {
> >           return r;
> >       }
> >
> > -    file.fd = event_notifier_get_fd(&vq->masked_notifier);
> > -    r = dev->vhost_ops->vhost_call(dev, VHOST_SET_VRING_CALL, &file);
> > -    if (r) {
> > -        r = -errno;
> > -        goto fail_call;
> > -    }
> >       return 0;
> > -fail_call:
> > -    event_notifier_cleanup(&vq->masked_notifier);
> > -    return r;
> >   }
> >
> >   static void vhost_virtqueue_cleanup(struct vhost_virtqueue *vq)
> > --
> > 2.1.0