[PATCH v2] virtio: add VIRTIO_RING_NO_LEGACY

From: Matej Genci
Date: Tue Sep 10 2019 - 13:53:52 EST


Add macro to disable legacy functions vring_init and vring_size.

Signed-off-by: Matej Genci <matej.genci@xxxxxxxxxxx>
---

V2: Put all legacy APIs inside guards.

---
include/uapi/linux/virtio_ring.h | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/include/uapi/linux/virtio_ring.h b/include/uapi/linux/virtio_ring.h
index 4c4e24c291a5..efe5a421b4ea 100644
--- a/include/uapi/linux/virtio_ring.h
+++ b/include/uapi/linux/virtio_ring.h
@@ -118,6 +118,8 @@ struct vring_used {
struct vring_used_elem ring[];
};

+#ifndef VIRTIO_RING_NO_LEGACY
+
struct vring {
unsigned int num;

@@ -128,6 +130,8 @@ struct vring {
struct vring_used *used;
};

+#endif /* VIRTIO_RING_NO_LEGACY */
+
/* Alignment requirements for vring elements.
* When using pre-virtio 1.0 layout, these fall out naturally.
*/
@@ -135,6 +139,8 @@ struct vring {
#define VRING_USED_ALIGN_SIZE 4
#define VRING_DESC_ALIGN_SIZE 16

+#ifndef VIRTIO_RING_NO_LEGACY
+
/* The standard layout for the ring is a continuous chunk of memory which looks
* like this. We assume num is a power of 2.
*
@@ -195,6 +201,8 @@ static inline int vring_need_event(__u16 event_idx, __u16 new_idx, __u16 old)
return (__u16)(new_idx - event_idx - 1) < (__u16)(new_idx - old);
}

+#endif /* VIRTIO_RING_NO_LEGACY */
+
struct vring_packed_desc_event {
/* Descriptor Ring Change Event Offset/Wrap Counter. */
__le16 off_wrap;
--
2.22.0