virtio: Add transport feature handling stub for virtio_ring.

To prepare for virtio_ring transport feature bits, hook in a call in
all the users to manipulate them.  This currently just clears all the
bits, since it doesn't understand any features.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h
index abe481ed990e..c4a598fb3826 100644
--- a/include/linux/virtio_ring.h
+++ b/include/linux/virtio_ring.h
@@ -120,6 +120,8 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
                                       void (*notify)(struct virtqueue *vq),
                                       void (*callback)(struct virtqueue *vq));
 void vring_del_virtqueue(struct virtqueue *vq);
+/* Filter out transport-specific feature bits. */
+void vring_transport_features(struct virtio_device *vdev);
 
 irqreturn_t vring_interrupt(int irq, void *_vq);
 #endif /* __KERNEL__ */