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Diffstat (limited to 'include/uapi/linux/virtio_ring.h')
-rw-r--r--include/uapi/linux/virtio_ring.h52
1 files changed, 30 insertions, 22 deletions
diff --git a/include/uapi/linux/virtio_ring.h b/include/uapi/linux/virtio_ring.h
index a99f9b7caa67..a3318f31e8e7 100644
--- a/include/uapi/linux/virtio_ring.h
+++ b/include/uapi/linux/virtio_ring.h
@@ -32,6 +32,7 @@
*
* Copyright Rusty Russell IBM Corporation 2007. */
#include <linux/types.h>
+#include <linux/virtio_types.h>
/* This marks a buffer as continuing via the next field. */
#define VRING_DESC_F_NEXT 1
@@ -61,32 +62,32 @@
/* Virtio ring descriptors: 16 bytes. These can chain together via "next". */
struct vring_desc {
/* Address (guest-physical). */
- __u64 addr;
+ __virtio64 addr;
/* Length. */
- __u32 len;
+ __virtio32 len;
/* The flags as indicated above. */
- __u16 flags;
+ __virtio16 flags;
/* We chain unused descriptors via this, too */
- __u16 next;
+ __virtio16 next;
};
struct vring_avail {
- __u16 flags;
- __u16 idx;
- __u16 ring[];
+ __virtio16 flags;
+ __virtio16 idx;
+ __virtio16 ring[];
};
/* u32 is used here for ids for padding reasons. */
struct vring_used_elem {
/* Index of start of used descriptor chain. */
- __u32 id;
+ __virtio32 id;
/* Total length of the descriptor chain which was used (written to) */
- __u32 len;
+ __virtio32 len;
};
struct vring_used {
- __u16 flags;
- __u16 idx;
+ __virtio16 flags;
+ __virtio16 idx;
struct vring_used_elem ring[];
};
@@ -100,6 +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.
*
@@ -109,25 +117,25 @@ struct vring {
* struct vring_desc desc[num];
*
* // A ring of available descriptor heads with free-running index.
- * __u16 avail_flags;
- * __u16 avail_idx;
- * __u16 available[num];
- * __u16 used_event_idx;
+ * __virtio16 avail_flags;
+ * __virtio16 avail_idx;
+ * __virtio16 available[num];
+ * __virtio16 used_event_idx;
*
* // Padding to the next align boundary.
* char pad[];
*
* // A ring of used descriptor heads with free-running index.
- * __u16 used_flags;
- * __u16 used_idx;
+ * __virtio16 used_flags;
+ * __virtio16 used_idx;
* struct vring_used_elem used[num];
- * __u16 avail_event_idx;
+ * __virtio16 avail_event_idx;
* };
*/
/* We publish the used event index at the end of the available ring, and vice
* versa. They are at the end for backwards compatibility. */
#define vring_used_event(vr) ((vr)->avail->ring[(vr)->num])
-#define vring_avail_event(vr) (*(__u16 *)&(vr)->used->ring[(vr)->num])
+#define vring_avail_event(vr) (*(__virtio16 *)&(vr)->used->ring[(vr)->num])
static inline void vring_init(struct vring *vr, unsigned int num, void *p,
unsigned long align)
@@ -135,15 +143,15 @@ static inline void vring_init(struct vring *vr, unsigned int num, void *p,
vr->num = num;
vr->desc = p;
vr->avail = p + num*sizeof(struct vring_desc);
- vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + sizeof(__u16)
+ vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + sizeof(__virtio16)
+ align-1) & ~(align - 1));
}
static inline unsigned vring_size(unsigned int num, unsigned long align)
{
- return ((sizeof(struct vring_desc) * num + sizeof(__u16) * (3 + num)
+ return ((sizeof(struct vring_desc) * num + sizeof(__virtio16) * (3 + num)
+ align - 1) & ~(align - 1))
- + sizeof(__u16) * 3 + sizeof(struct vring_used_elem) * num;
+ + sizeof(__virtio16) * 3 + sizeof(struct vring_used_elem) * num;
}
/* The following is used with USED_EVENT_IDX and AVAIL_EVENT_IDX */