[PATCH 24/31] vhost: Add vhost_svq_get_last_used_idx

[Eugenio Pérez]

This way SVQ queues can be migrated.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
 hw/virtio/vhost-shadow-virtqueue.h | 1 +
 hw/virtio/vhost-shadow-virtqueue.c | 8 ++++++++
 2 files changed, 9 insertions(+)

diff --git a/hw/virtio/vhost-shadow-virtqueue.h 
b/hw/virtio/vhost-shadow-virtqueue.h
index c6f67d6f76..a2b0c6434d 100644
--- a/hw/virtio/vhost-shadow-virtqueue.h
+++ b/hw/virtio/vhost-shadow-virtqueue.h
@@ -30,6 +30,7 @@ const EventNotifier *vhost_svq_get_svq_call_notifier(
                                               const VhostShadowVirtqueue *svq);
 void vhost_svq_get_vring_addr(const VhostShadowVirtqueue *svq,
                               struct vhost_vring_addr *addr);
+uint16_t vhost_svq_get_last_used_idx(const VhostShadowVirtqueue *svq);
 uint16_t vhost_svq_get_num(const VhostShadowVirtqueue *svq);
 size_t vhost_svq_driver_area_size(const VhostShadowVirtqueue *svq);
 size_t vhost_svq_device_area_size(const VhostShadowVirtqueue *svq);
diff --git a/hw/virtio/vhost-shadow-virtqueue.c 
b/hw/virtio/vhost-shadow-virtqueue.c
index c7888eb8cf..eb0a3fcb80 100644
--- a/hw/virtio/vhost-shadow-virtqueue.c
+++ b/hw/virtio/vhost-shadow-virtqueue.c
@@ -574,6 +574,14 @@ void vhost_svq_get_vring_addr(const VhostShadowVirtqueue 
*svq,
     addr->used_user_addr = (uint64_t)svq->vring.used;
 }
 
+/**
+ * Get the next index that SVQ is going to consume from SVQ used ring.
+ */
+uint16_t vhost_svq_get_last_used_idx(const VhostShadowVirtqueue *svq)
+{
+    return svq->last_used_idx;
+}
+
 uint16_t vhost_svq_get_num(const VhostShadowVirtqueue *svq)
 {
     return svq->vring.num;
-- 
2.27.0