Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull vhost cleanup and virtio bugfix
 "There's a single change here, fixing a vhost bug where vhost
  initialization fails due to used ring alignment check being too
  strict"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost: relax used address alignment
  virtio_ring: document alignment requirements

1 files changed, 7 insertions, 0 deletions

diff --git a/include/uapi/linux/virtio_ring.h b/include/uapi/linux/virtio_ring.h
index 61c818a7fe70..a3318f31e8e7 100644
--- a/include/uapi/linux/virtio_ring.h
+++ b/include/uapi/linux/virtio_ring.h
@@ -101,6 +101,13 @@ struct vring {
         struct vring_used *used;
 };
 
+/* Alignment requirements for vring elements.
+ * When using pre-virtio 1.0 layout, these fall out naturally.
+ */
+#define VRING_AVAIL_ALIGN_SIZE 2
+#define VRING_USED_ALIGN_SIZE 4
+#define VRING_DESC_ALIGN_SIZE 16
+
 /* The standard layout for the ring is a continuous chunk of memory which looks
  * like this.  We assume num is a power of 2.
  *