dataplane: stop trying on notifier error

If we fail to set up guest or host notifiers, there's no use trying again
every time the guest kicks, so disable dataplane in that case.

Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
index 94e1a29..24a6b71 100644 (file)
--- a/hw/block/dataplane/virtio-blk.c
+++ b/hw/block/dataplane/virtio-blk.c
@@ -28,6 +28,7 @@ struct VirtIOBlockDataPlane {
     bool started;
     bool starting;
     bool stopping;
+    bool disabled;
 
     VirtIOBlkConf *blk;
 
@@ -220,7 +221,7 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
     VirtQueue *vq;
     int r;
 
-    if (s->started) {
+    if (s->started || s->disabled) {
         return;
     }
 
@@ -274,6 +275,7 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
     k->set_guest_notifiers(qbus->parent, 1, false);
   fail_guest_notifiers:
     vring_teardown(&s->vring, s->vdev, 0);
+    s->disabled = true;
   fail_vring:
     s->starting = false;
 }
@@ -284,6 +286,13 @@ void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s)
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s->vdev)));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
     VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
+
+
+    /* Better luck next time. */
+    if (s->disabled) {
+        s->disabled = false;
+        return;
+    }
     if (!s->started || s->stopping) {
         return;
     }