vdpa: Fix bad index calculus at vhost_vdpa_get_vring_base

Fixes: 6d0b222666 ("vdpa: Adapt vhost_vdpa_get_vring_base to SVQ")

Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Message-Id: <20220512175747.142058-4-eperezma@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index a30510e..493269b 100644 (file)
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -1172,11 +1172,11 @@ static int vhost_vdpa_get_vring_base(struct vhost_dev *dev,
                                        struct vhost_vring_state *ring)
 {
     struct vhost_vdpa *v = dev->opaque;
+    int vdpa_idx = ring->index - dev->vq_index;
     int ret;
 
     if (v->shadow_vqs_enabled) {
-        VhostShadowVirtqueue *svq = g_ptr_array_index(v->shadow_vqs,
-                                                      ring->index);
+        VhostShadowVirtqueue *svq = g_ptr_array_index(v->shadow_vqs, vdpa_idx);
 
         /*
          * Setting base as last used idx, so destination will see as available