On Tue, 22 Mar 2016 07:45:19 +0800
Fam Zheng <f...@redhat.com> wrote:
> On Mon, 03/21 14:02, Cornelia Huck wrote:
> > On Mon, 21 Mar 2016 20:45:27 +0800
> > Fam Zheng <f...@redhat.com> wrote:
> >
> > > On Mon, 03/21 12:15, Cornelia Huck wrote:
> > > > On Mon, 21 Mar 2016 18:57:18 +0800
> > > > Fam Zheng <f...@redhat.com> wrote:
> > > >
> > > > > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> > > > > index 08275a9..47f8043 100644
> > > > > --- a/hw/virtio/virtio.c
> > > > > +++ b/hw/virtio/virtio.c
> > > > > @@ -1098,7 +1098,14 @@ void virtio_queue_notify_vq(VirtQueue *vq)
> > > > >
> > > > > void virtio_queue_notify(VirtIODevice *vdev, int n)
> > > > > {
> > > > > - virtio_queue_notify_vq(&vdev->vq[n]);
> > > > > + VirtQueue *vq = &vdev->vq[n];
> > > > > + EventNotifier *n;
> > > > > + n = virtio_queue_get_host_notifier(vq);
> > > > > + if (n) {
> > > >
> > > > Isn't that always true, even if the notifier has not been setup?
> > >
> > > You are right, this doesn't make a correct fix. But we can still do a
> > > quick
> > > test with this as the else branch should never be used with ioeventfd=on.
> > > Am I
> > > right?
> > >
> > > Fam
> >
> > Won't we come through here for the very first kick, when we haven't
> > registered the ioeventfd with the kernel yet?
> >
>
> The ioeventfd in virtio-ccw is registered in the main loop when
> VIRTIO_CONFIG_S_DRIVER_OK is set, so I think the first kick is okay.
You're right, for well-behaved drivers this will be done from
set_status, so for testing that's fine.
