@@ -1224,8 +1224,28 @@ static int tap_recvmsg(struct socket *sock, struct msghdr *m,
size_t total_len, int flags)
{
struct tap_queue *q = container_of(sock, struct tap_queue, sock);
- struct sk_buff *skb = m->msg_control;
+ struct tun_msg_ctl *ctl = m->msg_control;
+ struct sk_buff *skb = NULL;
int ret;
+
+ if (ctl) {
+ switch (ctl->type) {
+ case TUN_MSG_PKT:
+ skb = ctl->ptr;
+ break;
+ case TUN_MSG_CONSUME_PKTS:
+ return ptr_ring_consume_batched(&q->ring,
+ ctl->ptr,
+ ctl->num);
+ case TUN_MSG_UNCONSUME_PKTS:
+ ptr_ring_unconsume(&q->ring, ctl->ptr, ctl->num,
+ tun_ptr_free);
+ return 0;
+ default:
+ return -EINVAL;
+ }
+ }
+
if (flags & ~(MSG_DONTWAIT|MSG_TRUNC)) {
kfree_skb(skb);
return -EINVAL;
@@ -2577,7 +2577,8 @@ static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len,
{
struct tun_file *tfile = container_of(sock, struct tun_file, socket);
struct tun_struct *tun = tun_get(tfile);
- void *ptr = m->msg_control;
+ struct tun_msg_ctl *ctl = m->msg_control;
+ void *ptr = NULL;
int ret;
if (!tun) {
@@ -2585,6 +2586,27 @@ static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len,
goto out_free;
}
+ if (ctl) {
+ switch (ctl->type) {
+ case TUN_MSG_PKT:
+ ptr = ctl->ptr;
+ break;
+ case TUN_MSG_CONSUME_PKTS:
+ ret = ptr_ring_consume_batched(&tfile->tx_ring,
+ ctl->ptr,
+ ctl->num);
+ goto out;
+ case TUN_MSG_UNCONSUME_PKTS:
+ ptr_ring_unconsume(&tfile->tx_ring, ctl->ptr,
+ ctl->num, tun_ptr_free);
+ ret = 0;
+ goto out;
+ default:
+ ret = -EINVAL;
+ goto out_put_tun;
+ }
+ }
+
if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
ret = -EINVAL;
goto out_put_tun;
@@ -175,24 +175,44 @@ static void *vhost_net_buf_consume(struct vhost_net_buf *rxq)
static int vhost_net_buf_produce(struct vhost_net_virtqueue *nvq)
{
+ struct vhost_virtqueue *vq = &nvq->vq;
+ struct socket *sock = vq->private_data;
struct vhost_net_buf *rxq = &nvq->rxq;
+ struct tun_msg_ctl ctl = {
+ .type = TUN_MSG_CONSUME_PKTS,
+ .ptr = (void *) rxq->queue,
+ .num = VHOST_NET_BATCH,
+ };
+ struct msghdr msg = {
+ .msg_control = &ctl,
+ };
rxq->head = 0;
- rxq->tail = ptr_ring_consume_batched(nvq->rx_ring, rxq->queue,
- VHOST_NET_BATCH);
+ rxq->tail = sock->ops->recvmsg(sock, &msg, 0, 0);
+ if (WARN_ON_ONCE(rxq->tail < 0))
+ rxq->tail = 0;
+
return rxq->tail;
}
static void vhost_net_buf_unproduce(struct vhost_net_virtqueue *nvq)
{
+ struct vhost_virtqueue *vq = &nvq->vq;
+ struct socket *sock = vq->private_data;
struct vhost_net_buf *rxq = &nvq->rxq;
+ struct tun_msg_ctl ctl = {
+ .type = TUN_MSG_UNCONSUME_PKTS,
+ .ptr = (void *) (rxq->queue + rxq->head),
+ .num = vhost_net_buf_get_size(rxq),
+ };
+ struct msghdr msg = {
+ .msg_control = &ctl,
+ };
- if (nvq->rx_ring && !vhost_net_buf_is_empty(rxq)) {
- ptr_ring_unconsume(nvq->rx_ring, rxq->queue + rxq->head,
- vhost_net_buf_get_size(rxq),
- tun_ptr_free);
- rxq->head = rxq->tail = 0;
- }
+ if (!vhost_net_buf_is_empty(rxq))
+ sock->ops->recvmsg(sock, &msg, 0, 0);
+
+ rxq->head = rxq->tail = 0;
}
static int vhost_net_buf_peek_len(void *ptr)
@@ -1109,6 +1129,7 @@ static void handle_rx(struct vhost_net *net)
.flags = 0,
.gso_type = VIRTIO_NET_HDR_GSO_NONE
};
+ struct tun_msg_ctl ctl;
size_t total_len = 0;
int err, mergeable;
s16 headcount;
@@ -1166,8 +1187,11 @@ static void handle_rx(struct vhost_net *net)
goto out;
}
busyloop_intr = false;
- if (nvq->rx_ring)
- msg.msg_control = vhost_net_buf_consume(&nvq->rxq);
+ if (nvq->rx_ring) {
+ ctl.type = TUN_MSG_PKT;
+ ctl.ptr = vhost_net_buf_consume(&nvq->rxq);
+ msg.msg_control = &ctl;
+ }
/* On overrun, truncate and discard */
if (unlikely(headcount > UIO_MAXIOV)) {
iov_iter_init(&msg.msg_iter, READ, vq->iov, 1, 1);
@@ -1346,8 +1370,8 @@ static struct socket *vhost_net_stop_vq(struct vhost_net *n,
mutex_lock(&vq->mutex);
sock = vq->private_data;
vhost_net_disable_vq(n, vq);
- vq->private_data = NULL;
vhost_net_buf_unproduce(nvq);
+ vq->private_data = NULL;
nvq->rx_ring = NULL;
mutex_unlock(&vq->mutex);
return sock;
@@ -1538,8 +1562,8 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
}
vhost_net_disable_vq(n, vq);
- vq->private_data = sock;
vhost_net_buf_unproduce(nvq);
+ vq->private_data = sock;
r = vhost_vq_init_access(vq);
if (r)
goto err_used;
@@ -11,8 +11,26 @@
#define TUN_XDP_FLAG 0x1UL
+/*
+ * tun_msg_ctl types
+ */
+
#define TUN_MSG_UBUF 1
#define TUN_MSG_PTR 2
+/*
+ * Used for passing a packet pointer from vhost to tun
+ */
+#define TUN_MSG_PKT 3
+/*
+ * Used for passing an array of pointer from vhost to tun.
+ * tun consumes packets from ptr ring and stores in pointer array.
+ */
+#define TUN_MSG_CONSUME_PKTS 4
+/*
+ * Used for passing an array of pointer from vhost to tun.
+ * tun consumes get pointer from array and puts back into ptr ring.
+ */
+#define TUN_MSG_UNCONSUME_PKTS 5
struct tun_msg_ctl {
unsigned short type;
unsigned short num;
Currently vhost_net directly accesses ptr ring of tap driver to fetch Rx packet pointers. In order to avoid it this patch modifies tap driver's recvmsg api to do additional task of fetching Rx packet pointers. A special struct tun_msg_ctl is already being passed via msg_control for tun Rx XDP batching. This patch extends tun_msg_ctl usage to send sub commands to recvmsg api. Now tun_recvmsg will handle commands to consume and unconsume packet pointers from ptr ring. This will be useful in implementation of tx path XDP in tun driver, where XDP program will process the packet before it is passed to vhost_net. Signed-off-by: Prashant Bhole <prashantbhole.linux@gmail.com> --- drivers/net/tap.c | 22 ++++++++++++++++++- drivers/net/tun.c | 24 ++++++++++++++++++++- drivers/vhost/net.c | 48 +++++++++++++++++++++++++++++++----------- include/linux/if_tun.h | 18 ++++++++++++++++ 4 files changed, 98 insertions(+), 14 deletions(-)