vhost: support event index

Support the new event index feature. When acked,
utilize it to reduce the # of interrupts sent to the guest.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Michael S. Tsirkin
2011-05-20 02:10:54 +03:00
committed by Rusty Russell
parent a5c262c5fd
commit 8ea8cf89e1
4 changed files with 127 additions and 50 deletions

View File

@@ -84,6 +84,12 @@ struct vhost_virtqueue {
/* Used flags */
u16 used_flags;
/* Last used index value we have signalled on */
u16 signalled_used;
/* Last used index value we have signalled on */
bool signalled_used_valid;
/* Log writes to used structure. */
bool log_used;
u64 log_addr;
@@ -149,8 +155,8 @@ void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
struct vring_used_elem *heads, unsigned count);
void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
void vhost_disable_notify(struct vhost_virtqueue *);
bool vhost_enable_notify(struct vhost_virtqueue *);
void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
unsigned int log_num, u64 len);
@@ -162,11 +168,12 @@ int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
} while (0)
enum {
VHOST_FEATURES = (1 << VIRTIO_F_NOTIFY_ON_EMPTY) |
(1 << VIRTIO_RING_F_INDIRECT_DESC) |
(1 << VHOST_F_LOG_ALL) |
(1 << VHOST_NET_F_VIRTIO_NET_HDR) |
(1 << VIRTIO_NET_F_MRG_RXBUF),
VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
(1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
(1ULL << VIRTIO_RING_F_EVENT_IDX) |
(1ULL << VHOST_F_LOG_ALL) |
(1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
(1ULL << VIRTIO_NET_F_MRG_RXBUF),
};
static inline int vhost_has_feature(struct vhost_dev *dev, int bit)