virtio-blk: always use dataplane path if ioeventfd is active

Override start_ioeventfd and stop_ioeventfd to start/stop the
whole dataplane logic.  This has some positive side effects:

- no need anymore for virtio_add_queue_aio (i.e. a revert of
  commit 0ff841f6d138904d514efa1d885bcaf54583852d)

- no need anymore to switch from generic ioeventfd handlers to
  dataplane

It detects some errors better:

    $ qemu-system-x86_64 -object iothread,id=io \
          -drive id=null,file=null-aio://,if=none,format=raw \
          -device virtio-blk-pci,ioeventfd=off,iothread=io,drive=null
    qemu-system-x86_64: -device virtio-blk-pci,ioeventfd=off,iothread=io,drive=null:
    ioeventfd is required for iothread

while previously it would have started just fine.

Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/hw/block/dataplane/virtio-blk.h b/hw/block/dataplane/virtio-blk.h
index b1f0b95b32..db3f47b173 100644
--- a/hw/block/dataplane/virtio-blk.h
+++ b/hw/block/dataplane/virtio-blk.h
@@ -23,9 +23,9 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *conf,
                                   VirtIOBlockDataPlane **dataplane,
                                   Error **errp);
 void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s);
-void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s);
-void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s);
-void virtio_blk_data_plane_drain(VirtIOBlockDataPlane *s);
 void virtio_blk_data_plane_notify(VirtIOBlockDataPlane *s, VirtQueue *vq);
 
+int virtio_blk_data_plane_start(VirtIODevice *vdev);
+void virtio_blk_data_plane_stop(VirtIODevice *vdev);
+
 #endif /* HW_DATAPLANE_VIRTIO_BLK_H */