Jason Wang
2021-Mar-16 08:07 UTC
[RFC v2 12/13] vhost: Check for device VRING_USED_F_NO_NOTIFY at shadow virtqueue kick
? 2021/3/16 ??3:48, Eugenio P?rez ??:> Signed-off-by: Eugenio P?rez <eperezma at redhat.com> > --- > hw/virtio/vhost-shadow-virtqueue.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c > index 68ed0f2740..7df98fc43f 100644 > --- a/hw/virtio/vhost-shadow-virtqueue.c > +++ b/hw/virtio/vhost-shadow-virtqueue.c > @@ -145,6 +145,15 @@ static void vhost_shadow_vq_add(VhostShadowVirtqueue *svq, > svq->ring_id_maps[qemu_head] = elem; > } > > +static void vhost_shadow_vq_kick(VhostShadowVirtqueue *svq) > +{ > + /* Make sure we are reading updated device flag */ > + smp_rmb();smp_mb() actually? Or it's better to explain this following read needs to be orderd with what read before. Thanks> + if (!(svq->vring.used->flags & VRING_USED_F_NO_NOTIFY)) { > + event_notifier_set(&svq->kick_notifier); > + } > +} > + > /* Handle guest->device notifications */ > static void vhost_handle_guest_kick(EventNotifier *n) > { > @@ -174,7 +183,7 @@ static void vhost_handle_guest_kick(EventNotifier *n) > } > > vhost_shadow_vq_add(svq, elem); > - event_notifier_set(&svq->kick_notifier); > + vhost_shadow_vq_kick(svq); > } > > virtio_queue_set_notification(svq->vq, true);