If the virtio transport does not support notifiers (like s390-virtio),
we can't use dataplane. Bail out early and let the user know what is
wrong.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>