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-rw-r--r--hw/virtio/vhost-shadow-virtqueue.c18
1 files changed, 15 insertions, 3 deletions
diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c
index a518f84772..f5c0fad3fc 100644
--- a/hw/virtio/vhost-shadow-virtqueue.c
+++ b/hw/virtio/vhost-shadow-virtqueue.c
@@ -369,15 +369,27 @@ static bool vhost_svq_more_used(VhostShadowVirtqueue *svq)
*/
static bool vhost_svq_enable_notification(VhostShadowVirtqueue *svq)
{
- svq->vring.avail->flags &= ~cpu_to_le16(VRING_AVAIL_F_NO_INTERRUPT);
- /* Make sure the flag is written before the read of used_idx */
+ if (virtio_vdev_has_feature(svq->vdev, VIRTIO_RING_F_EVENT_IDX)) {
+ uint16_t *used_event = (uint16_t *)&svq->vring.avail->ring[svq->vring.num];
+ *used_event = svq->shadow_used_idx;
+ } else {
+ svq->vring.avail->flags &= ~cpu_to_le16(VRING_AVAIL_F_NO_INTERRUPT);
+ }
+
+ /* Make sure the event is enabled before the read of used_idx */
smp_mb();
return !vhost_svq_more_used(svq);
}
static void vhost_svq_disable_notification(VhostShadowVirtqueue *svq)
{
- svq->vring.avail->flags |= cpu_to_le16(VRING_AVAIL_F_NO_INTERRUPT);
+ /*
+ * No need to disable notification in the event idx case, since used event
+ * index is already an index too far away.
+ */
+ if (!virtio_vdev_has_feature(svq->vdev, VIRTIO_RING_F_EVENT_IDX)) {
+ svq->vring.avail->flags |= cpu_to_le16(VRING_AVAIL_F_NO_INTERRUPT);
+ }
}
static uint16_t vhost_svq_last_desc_of_chain(const VhostShadowVirtqueue *svq,