virtio_ccw: rev 1 devices set VIRTIO_F_VERSION_1

What does it mean if rev 1 device does not set
VIRTIO_F_VERSION_1? E.g. is it native endian?

Let's not even try to drive such devices:
fail attempts to finalize features.
virtio core will detect this and bail out.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/s390/kvm/virtio_ccw.c

@@ -758,6 +758,13 @@ static int virtio_ccw_finalize_features(struct virtio_device *vdev)
 	struct virtio_feature_desc *features;
 	struct ccw1 *ccw;
 
+	if (vcdev->revision == 1 &&
+	    !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
+		dev_err(&vdev->dev, "virtio: device uses revision 1 "
+			"but does not have VIRTIO_F_VERSION_1\n");
+		return -EINVAL;
+	}
+
 	ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
 	if (!ccw)
 		return 0;