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>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
index 789275fb577f..f9f87ba013c9 100644
--- a/drivers/s390/kvm/virtio_ccw.c
+++ b/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;