#define VRING_DESC_F_NEXT 1
/* This marks a buffer as write-only (otherwise read-only). */
#define VRING_DESC_F_WRITE 2
+/* This means the buffer contains a list of buffer descriptors. */
+#define VRING_DESC_F_INDIRECT 4
-/* This means don't notify other side when buffer added. */
+/* The Host uses this in used->flags to advise the Guest: don't kick me when
+ * you add a buffer. It's unreliable, so it's simply an optimization. Guest
+ * will still kick if it's out of buffers. */
#define VRING_USED_F_NO_NOTIFY 1
-/* This means don't interrupt guest when buffer consumed. */
+/* The Guest uses this in avail->flags to advise the Host: don't interrupt me
+ * when you consume a buffer. It's unreliable, so it's simply an
+ * optimization. */
#define VRING_AVAIL_F_NO_INTERRUPT 1
+/* We support indirect buffer descriptors */
+#define VIRTIO_RING_F_INDIRECT_DESC 28
+
/* Virtio ring descriptors: 16 bytes. These can chain together via "next". */
-struct vring_desc
-{
+struct vring_desc {
/* Address (guest-physical). */
__u64 addr;
/* Length. */
__u16 next;
};
-struct vring_avail
-{
+struct vring_avail {
__u16 flags;
__u16 idx;
__u16 ring[];
};
/* u32 is used here for ids for padding reasons. */
-struct vring_used_elem
-{
+struct vring_used_elem {
/* Index of start of used descriptor chain. */
__u32 id;
/* Total length of the descriptor chain which was used (written to) */
__u32 len;
};
-struct vring_used
-{
+struct vring_used {
__u16 flags;
__u16 idx;
struct vring_used_elem ring[];
* __u16 avail_idx;
* __u16 available[num];
*
- * // Padding to the next page boundary.
+ * // Padding to the next align boundary.
* char pad[];
*
* // A ring of used descriptor heads with free-running index.
* };
*/
static inline void vring_init(struct vring *vr, unsigned int num, void *p,
- unsigned long pagesize)
+ unsigned long align)
{
vr->num = num;
vr->desc = p;
vr->avail = p + num*sizeof(struct vring_desc);
- vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + pagesize-1)
- & ~(pagesize - 1));
+ vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + align-1)
+ & ~(align - 1));
}
-static inline unsigned vring_size(unsigned int num, unsigned long pagesize)
+static inline unsigned vring_size(unsigned int num, unsigned long align)
{
return ((sizeof(struct vring_desc) * num + sizeof(__u16) * (2 + num)
- + pagesize - 1) & ~(pagesize - 1))
+ + align - 1) & ~(align - 1))
+ sizeof(__u16) * 2 + sizeof(struct vring_used_elem) * num;
}
struct virtqueue;
struct virtqueue *vring_new_virtqueue(unsigned int num,
+ unsigned int vring_align,
struct virtio_device *vdev,
void *pages,
void (*notify)(struct virtqueue *vq),
- void (*callback)(struct virtqueue *vq));
+ void (*callback)(struct virtqueue *vq),
+ const char *name);
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__ */