Read only feature shouldn't be negotiable, because if the
backend device reported Read only feature supported, QEMU
host driver shouldn't change backend's RO attribute. While
here, also enable the vhost-user-blk test utility to test
RO feature.
Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>