[Qemu-devel] [PULL 25/41] net: Add virtio queue interface to update used index from vring state

["Michael S. Tsirkin" <mst@redhat.com>]

From: Yuri Benditovich <yuri.benditovich@daynix.com>

Bring virtio queue to correct internal  state for host-to-guest
operations when vhost is temporary stopped.

Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 include/hw/virtio/virtio.h | 1 +
 hw/virtio/virtio.c         | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 5e4176f..e15c064 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -269,6 +269,7 @@ hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n);
 uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx);
 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n);
+void virtio_queue_update_used_idx(VirtIODevice *vdev, int n);
 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
 uint16_t virtio_get_queue_index(VirtQueue *vq);
 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 8357218..baffff7 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -2020,6 +2020,11 @@ void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx)
     vdev->vq[n].shadow_avail_idx = idx;
 }
 
+void virtio_queue_update_used_idx(VirtIODevice *vdev, int n)
+{
+    vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]);
+}
+
 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n)
 {
     vdev->vq[n].signalled_used_valid = false;
-- 
MST