[Qemu-devel] [PATCH 1/9] virtio-dataplane: pass assign=true to virtio_queue_aio_set_host_notifier_handler

[Paolo Bonzini]

There is no need to run the handler one last time; the device is being
reset and it is okay to drop requests that are pending in the virtqueue.
By omitting this call, we dodge a possible cause of races between the
dataplane thread on one side and the main/vCPU threads on the other.

Signed-off-by: Paolo Bonzini <address@hidden>
---
 hw/block/dataplane/virtio-blk.c | 2 +-
 hw/scsi/virtio-scsi-dataplane.c | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
index 36f3d2b..0d76110 100644
--- a/hw/block/dataplane/virtio-blk.c
+++ b/hw/block/dataplane/virtio-blk.c
@@ -261,7 +261,7 @@ void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s)
     aio_context_acquire(s->ctx);
 
     /* Stop notifications for new requests from guest */
-    virtio_queue_aio_set_host_notifier_handler(s->vq, s->ctx, false, false);
+    virtio_queue_aio_set_host_notifier_handler(s->vq, s->ctx, true, false);
 
     /* Drain and switch bs back to the QEMU main loop */
     blk_set_aio_context(s->conf->conf.blk, qemu_get_aio_context());
diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c
index 367e476..c57480e 100644
--- a/hw/scsi/virtio-scsi-dataplane.c
+++ b/hw/scsi/virtio-scsi-dataplane.c
@@ -71,10 +71,10 @@ static void virtio_scsi_clear_aio(VirtIOSCSI *s)
     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
     int i;
 
-    virtio_queue_aio_set_host_notifier_handler(vs->ctrl_vq, s->ctx, false, 
false);
-    virtio_queue_aio_set_host_notifier_handler(vs->event_vq, s->ctx, false, 
false);
+    virtio_queue_aio_set_host_notifier_handler(vs->ctrl_vq, s->ctx, true, 
false);
+    virtio_queue_aio_set_host_notifier_handler(vs->event_vq, s->ctx, true, 
false);
     for (i = 0; i < vs->conf.num_queues; i++) {
-        virtio_queue_aio_set_host_notifier_handler(vs->cmd_vqs[i], s->ctx, 
false, false);
+        virtio_queue_aio_set_host_notifier_handler(vs->cmd_vqs[i], s->ctx, 
true, false);
     }
 }
 
-- 
1.8.3.1