1 files changed, 250 insertions, 76 deletions

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 4e656f89cb22..ab11b2bee273 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -116,6 +116,8 @@ struct vhost_net_virtqueue {
 	 * For RX, number of batched heads
 	 */
 	int done_idx;
+	/* Number of XDP frames batched */
+	int batched_xdp;
 	/* an array of userspace buffers info */
 	struct ubuf_info *ubuf_info;
 	/* Reference counting for outstanding ubufs.
@@ -123,6 +125,8 @@ struct vhost_net_virtqueue {
 	struct vhost_net_ubuf_ref *ubufs;
 	struct ptr_ring *rx_ring;
 	struct vhost_net_buf rxq;
+	/* Batched XDP buffs */
+	struct xdp_buff *xdp;
 };
 
 struct vhost_net {
@@ -338,6 +342,11 @@ static bool vhost_sock_zcopy(struct socket *sock)
 		sock_flag(sock->sk, SOCK_ZEROCOPY);
 }
 
+static bool vhost_sock_xdp(struct socket *sock)
+{
+	return sock_flag(sock->sk, SOCK_XDP);
+}
+
 /* In case of DMA done not in order in lower device driver for some reason.
  * upend_idx is used to track end of used idx, done_idx is used to track head
  * of used idx. Once lower device DMA done contiguously, we will signal KVM
@@ -444,32 +453,120 @@ static void vhost_net_signal_used(struct vhost_net_virtqueue *nvq)
 	nvq->done_idx = 0;
 }
 
+static void vhost_tx_batch(struct vhost_net *net,
+			   struct vhost_net_virtqueue *nvq,
+			   struct socket *sock,
+			   struct msghdr *msghdr)
+{
+	struct tun_msg_ctl ctl = {
+		.type = TUN_MSG_PTR,
+		.num = nvq->batched_xdp,
+		.ptr = nvq->xdp,
+	};
+	int err;
+
+	if (nvq->batched_xdp == 0)
+		goto signal_used;
+
+	msghdr->msg_control = &ctl;
+	err = sock->ops->sendmsg(sock, msghdr, 0);
+	if (unlikely(err < 0)) {
+		vq_err(&nvq->vq, "Fail to batch sending packets\n");
+		return;
+	}
+
+signal_used:
+	vhost_net_signal_used(nvq);
+	nvq->batched_xdp = 0;
+}
+
+static int sock_has_rx_data(struct socket *sock)
+{
+	if (unlikely(!sock))
+		return 0;
+
+	if (sock->ops->peek_len)
+		return sock->ops->peek_len(sock);
+
+	return skb_queue_empty(&sock->sk->sk_receive_queue);
+}
+
+static void vhost_net_busy_poll_try_queue(struct vhost_net *net,
+					  struct vhost_virtqueue *vq)
+{
+	if (!vhost_vq_avail_empty(&net->dev, vq)) {
+		vhost_poll_queue(&vq->poll);
+	} else if (unlikely(vhost_enable_notify(&net->dev, vq))) {
+		vhost_disable_notify(&net->dev, vq);
+		vhost_poll_queue(&vq->poll);
+	}
+}
+
+static void vhost_net_busy_poll(struct vhost_net *net,
+				struct vhost_virtqueue *rvq,
+				struct vhost_virtqueue *tvq,
+				bool *busyloop_intr,
+				bool poll_rx)
+{
+	unsigned long busyloop_timeout;
+	unsigned long endtime;
+	struct socket *sock;
+	struct vhost_virtqueue *vq = poll_rx ? tvq : rvq;
+
+	mutex_lock_nested(&vq->mutex, poll_rx ? VHOST_NET_VQ_TX: VHOST_NET_VQ_RX);
+	vhost_disable_notify(&net->dev, vq);
+	sock = rvq->private_data;
+
+	busyloop_timeout = poll_rx ? rvq->busyloop_timeout:
+				     tvq->busyloop_timeout;
+
+	preempt_disable();
+	endtime = busy_clock() + busyloop_timeout;
+
+	while (vhost_can_busy_poll(endtime)) {
+		if (vhost_has_work(&net->dev)) {
+			*busyloop_intr = true;
+			break;
+		}
+
+		if ((sock_has_rx_data(sock) &&
+		     !vhost_vq_avail_empty(&net->dev, rvq)) ||
+		    !vhost_vq_avail_empty(&net->dev, tvq))
+			break;
+
+		cpu_relax();
+	}
+
+	preempt_enable();
+
+	if (poll_rx || sock_has_rx_data(sock))
+		vhost_net_busy_poll_try_queue(net, vq);
+	else if (!poll_rx) /* On tx here, sock has no rx data. */
+		vhost_enable_notify(&net->dev, rvq);
+
+	mutex_unlock(&vq->mutex);
+}
+
 static int vhost_net_tx_get_vq_desc(struct vhost_net *net,
-				    struct vhost_net_virtqueue *nvq,
+				    struct vhost_net_virtqueue *tnvq,
 				    unsigned int *out_num, unsigned int *in_num,
-				    bool *busyloop_intr)
+				    struct msghdr *msghdr, bool *busyloop_intr)
 {
-	struct vhost_virtqueue *vq = &nvq->vq;
-	unsigned long uninitialized_var(endtime);
-	int r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
+	struct vhost_net_virtqueue *rnvq = &net->vqs[VHOST_NET_VQ_RX];
+	struct vhost_virtqueue *rvq = &rnvq->vq;
+	struct vhost_virtqueue *tvq = &tnvq->vq;
+
+	int r = vhost_get_vq_desc(tvq, tvq->iov, ARRAY_SIZE(tvq->iov),
 				  out_num, in_num, NULL, NULL);
 
-	if (r == vq->num && vq->busyloop_timeout) {
-		if (!vhost_sock_zcopy(vq->private_data))
-			vhost_net_signal_used(nvq);
-		preempt_disable();
-		endtime = busy_clock() + vq->busyloop_timeout;
-		while (vhost_can_busy_poll(endtime)) {
-			if (vhost_has_work(vq->dev)) {
-				*busyloop_intr = true;
-				break;
-			}
-			if (!vhost_vq_avail_empty(vq->dev, vq))
-				break;
-			cpu_relax();
-		}
-		preempt_enable();
-		r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
+	if (r == tvq->num && tvq->busyloop_timeout) {
+		/* Flush batched packets first */
+		if (!vhost_sock_zcopy(tvq->private_data))
+			vhost_tx_batch(net, tnvq, tvq->private_data, msghdr);
+
+		vhost_net_busy_poll(net, rvq, tvq, busyloop_intr, false);
+
+		r = vhost_get_vq_desc(tvq, tvq->iov, ARRAY_SIZE(tvq->iov),
 				      out_num, in_num, NULL, NULL);
 	}
 
@@ -512,7 +609,7 @@ static int get_tx_bufs(struct vhost_net *net,
 	struct vhost_virtqueue *vq = &nvq->vq;
 	int ret;
 
-	ret = vhost_net_tx_get_vq_desc(net, nvq, out, in, busyloop_intr);
+	ret = vhost_net_tx_get_vq_desc(net, nvq, out, in, msg, busyloop_intr);
 
 	if (ret < 0 || ret == vq->num)
 		return ret;
@@ -540,6 +637,80 @@ static bool tx_can_batch(struct vhost_virtqueue *vq, size_t total_len)
 	       !vhost_vq_avail_empty(vq->dev, vq);
 }
 
+#define VHOST_NET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
+
+static int vhost_net_build_xdp(struct vhost_net_virtqueue *nvq,
+			       struct iov_iter *from)
+{
+	struct vhost_virtqueue *vq = &nvq->vq;
+	struct socket *sock = vq->private_data;
+	struct page_frag *alloc_frag = &current->task_frag;
+	struct virtio_net_hdr *gso;
+	struct xdp_buff *xdp = &nvq->xdp[nvq->batched_xdp];
+	struct tun_xdp_hdr *hdr;
+	size_t len = iov_iter_count(from);
+	int headroom = vhost_sock_xdp(sock) ? XDP_PACKET_HEADROOM : 0;
+	int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+	int pad = SKB_DATA_ALIGN(VHOST_NET_RX_PAD + headroom + nvq->sock_hlen);
+	int sock_hlen = nvq->sock_hlen;
+	void *buf;
+	int copied;
+
+	if (unlikely(len < nvq->sock_hlen))
+		return -EFAULT;
+
+	if (SKB_DATA_ALIGN(len + pad) +
+	    SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) > PAGE_SIZE)
+		return -ENOSPC;
+
+	buflen += SKB_DATA_ALIGN(len + pad);
+	alloc_frag->offset = ALIGN((u64)alloc_frag->offset, SMP_CACHE_BYTES);
+	if (unlikely(!skb_page_frag_refill(buflen, alloc_frag, GFP_KERNEL)))
+		return -ENOMEM;
+
+	buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
+	copied = copy_page_from_iter(alloc_frag->page,
+				     alloc_frag->offset +
+				     offsetof(struct tun_xdp_hdr, gso),
+				     sock_hlen, from);
+	if (copied != sock_hlen)
+		return -EFAULT;
+
+	hdr = buf;
+	gso = &hdr->gso;
+
+	if ((gso->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
+	    vhost16_to_cpu(vq, gso->csum_start) +
+	    vhost16_to_cpu(vq, gso->csum_offset) + 2 >
+	    vhost16_to_cpu(vq, gso->hdr_len)) {
+		gso->hdr_len = cpu_to_vhost16(vq,
+			       vhost16_to_cpu(vq, gso->csum_start) +
+			       vhost16_to_cpu(vq, gso->csum_offset) + 2);
+
+		if (vhost16_to_cpu(vq, gso->hdr_len) > len)
+			return -EINVAL;
+	}
+
+	len -= sock_hlen;
+	copied = copy_page_from_iter(alloc_frag->page,
+				     alloc_frag->offset + pad,
+				     len, from);
+	if (copied != len)
+		return -EFAULT;
+
+	xdp->data_hard_start = buf;
+	xdp->data = buf + pad;
+	xdp->data_end = xdp->data + len;
+	hdr->buflen = buflen;
+
+	get_page(alloc_frag->page);
+	alloc_frag->offset += buflen;
+
+	++nvq->batched_xdp;
+
+	return 0;
+}
+
 static void handle_tx_copy(struct vhost_net *net, struct socket *sock)
 {
 	struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX];
@@ -556,10 +727,14 @@ static void handle_tx_copy(struct vhost_net *net, struct socket *sock)
 	size_t len, total_len = 0;
 	int err;
 	int sent_pkts = 0;
+	bool sock_can_batch = (sock->sk->sk_sndbuf == INT_MAX);
 
 	for (;;) {
 		bool busyloop_intr = false;
 
+		if (nvq->done_idx == VHOST_NET_BATCH)
+			vhost_tx_batch(net, nvq, sock, &msg);
+
 		head = get_tx_bufs(net, nvq, &msg, &out, &in, &len,
 				   &busyloop_intr);
 		/* On error, stop handling until the next kick. */
@@ -577,14 +752,34 @@ static void handle_tx_copy(struct vhost_net *net, struct socket *sock)
 			break;
 		}
 
-		vq->heads[nvq->done_idx].id = cpu_to_vhost32(vq, head);
-		vq->heads[nvq->done_idx].len = 0;
-
 		total_len += len;
-		if (tx_can_batch(vq, total_len))
-			msg.msg_flags |= MSG_MORE;
-		else
-			msg.msg_flags &= ~MSG_MORE;
+
+		/* For simplicity, TX batching is only enabled if
+		 * sndbuf is unlimited.
+		 */
+		if (sock_can_batch) {
+			err = vhost_net_build_xdp(nvq, &msg.msg_iter);
+			if (!err) {
+				goto done;
+			} else if (unlikely(err != -ENOSPC)) {
+				vhost_tx_batch(net, nvq, sock, &msg);
+				vhost_discard_vq_desc(vq, 1);
+				vhost_net_enable_vq(net, vq);
+				break;
+			}
+
+			/* We can't build XDP buff, go for single
+			 * packet path but let's flush batched
+			 * packets.
+			 */
+			vhost_tx_batch(net, nvq, sock, &msg);
+			msg.msg_control = NULL;
+		} else {
+			if (tx_can_batch(vq, total_len))
+				msg.msg_flags |= MSG_MORE;
+			else
+				msg.msg_flags &= ~MSG_MORE;
+		}
 
 		/* TODO: Check specific error and bomb out unless ENOBUFS? */
 		err = sock->ops->sendmsg(sock, &msg, len);
@@ -596,15 +791,17 @@ static void handle_tx_copy(struct vhost_net *net, struct socket *sock)
 		if (err != len)
 			pr_debug("Truncated TX packet: len %d != %zd\n",
 				 err, len);
-		if (++nvq->done_idx >= VHOST_NET_BATCH)
-			vhost_net_signal_used(nvq);
+done:
+		vq->heads[nvq->done_idx].id = cpu_to_vhost32(vq, head);
+		vq->heads[nvq->done_idx].len = 0;
+		++nvq->done_idx;
 		if (vhost_exceeds_weight(++sent_pkts, total_len)) {
 			vhost_poll_queue(&vq->poll);
 			break;
 		}
 	}
 
-	vhost_net_signal_used(nvq);
+	vhost_tx_batch(net, nvq, sock, &msg);
 }
 
 static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
@@ -620,6 +817,7 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
 		.msg_controllen = 0,
 		.msg_flags = MSG_DONTWAIT,
 	};
+	struct tun_msg_ctl ctl;
 	size_t len, total_len = 0;
 	int err;
 	struct vhost_net_ubuf_ref *uninitialized_var(ubufs);
@@ -664,8 +862,10 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
 			ubuf->ctx = nvq->ubufs;
 			ubuf->desc = nvq->upend_idx;
 			refcount_set(&ubuf->refcnt, 1);
-			msg.msg_control = ubuf;
-			msg.msg_controllen = sizeof(ubuf);
+			msg.msg_control = &ctl;
+			ctl.type = TUN_MSG_UBUF;
+			ctl.ptr = ubuf;
+			msg.msg_controllen = sizeof(ctl);
 			ubufs = nvq->ubufs;
 			atomic_inc(&ubufs->refcount);
 			nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
@@ -716,7 +916,7 @@ static void handle_tx(struct vhost_net *net)
 	struct vhost_virtqueue *vq = &nvq->vq;
 	struct socket *sock;
 
-	mutex_lock(&vq->mutex);
+	mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_TX);
 	sock = vq->private_data;
 	if (!sock)
 		goto out;
@@ -757,16 +957,6 @@ static int peek_head_len(struct vhost_net_virtqueue *rvq, struct sock *sk)
 	return len;
 }
 
-static int sk_has_rx_data(struct sock *sk)
-{
-	struct socket *sock = sk->sk_socket;
-
-	if (sock->ops->peek_len)
-		return sock->ops->peek_len(sock);
-
-	return skb_queue_empty(&sk->sk_receive_queue);
-}
-
 static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk,
 				      bool *busyloop_intr)
 {
@@ -774,41 +964,13 @@ static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk,
 	struct vhost_net_virtqueue *tnvq = &net->vqs[VHOST_NET_VQ_TX];
 	struct vhost_virtqueue *rvq = &rnvq->vq;
 	struct vhost_virtqueue *tvq = &tnvq->vq;
-	unsigned long uninitialized_var(endtime);
 	int len = peek_head_len(rnvq, sk);
 
-	if (!len && tvq->busyloop_timeout) {
+	if (!len && rvq->busyloop_timeout) {
 		/* Flush batched heads first */
 		vhost_net_signal_used(rnvq);
 		/* Both tx vq and rx socket were polled here */
-		mutex_lock_nested(&tvq->mutex, 1);
-		vhost_disable_notify(&net->dev, tvq);
-
-		preempt_disable();
-		endtime = busy_clock() + tvq->busyloop_timeout;
-
-		while (vhost_can_busy_poll(endtime)) {
-			if (vhost_has_work(&net->dev)) {
-				*busyloop_intr = true;
-				break;
-			}
-			if ((sk_has_rx_data(sk) &&
-			     !vhost_vq_avail_empty(&net->dev, rvq)) ||
-			    !vhost_vq_avail_empty(&net->dev, tvq))
-				break;
-			cpu_relax();
-		}
-
-		preempt_enable();
-
-		if (!vhost_vq_avail_empty(&net->dev, tvq)) {
-			vhost_poll_queue(&tvq->poll);
-		} else if (unlikely(vhost_enable_notify(&net->dev, tvq))) {
-			vhost_disable_notify(&net->dev, tvq);
-			vhost_poll_queue(&tvq->poll);
-		}
-
-		mutex_unlock(&tvq->mutex);
+		vhost_net_busy_poll(net, rvq, tvq, busyloop_intr, true);
 
 		len = peek_head_len(rnvq, sk);
 	}
@@ -923,7 +1085,7 @@ static void handle_rx(struct vhost_net *net)
 	__virtio16 num_buffers;
 	int recv_pkts = 0;
 
-	mutex_lock_nested(&vq->mutex, 0);
+	mutex_lock_nested(&vq->mutex, VHOST_NET_VQ_RX);
 	sock = vq->private_data;
 	if (!sock)
 		goto out;
@@ -1078,6 +1240,7 @@ static int vhost_net_open(struct inode *inode, struct file *f)
 	struct vhost_dev *dev;
 	struct vhost_virtqueue **vqs;
 	void **queue;
+	struct xdp_buff *xdp;
 	int i;
 
 	n = kvmalloc(sizeof *n, GFP_KERNEL | __GFP_RETRY_MAYFAIL);
@@ -1098,6 +1261,15 @@ static int vhost_net_open(struct inode *inode, struct file *f)
 	}
 	n->vqs[VHOST_NET_VQ_RX].rxq.queue = queue;
 
+	xdp = kmalloc_array(VHOST_NET_BATCH, sizeof(*xdp), GFP_KERNEL);
+	if (!xdp) {
+		kfree(vqs);
+		kvfree(n);
+		kfree(queue);
+		return -ENOMEM;
+	}
+	n->vqs[VHOST_NET_VQ_TX].xdp = xdp;
+
 	dev = &n->dev;
 	vqs[VHOST_NET_VQ_TX] = &n->vqs[VHOST_NET_VQ_TX].vq;
 	vqs[VHOST_NET_VQ_RX] = &n->vqs[VHOST_NET_VQ_RX].vq;
@@ -1108,6 +1280,7 @@ static int vhost_net_open(struct inode *inode, struct file *f)
 		n->vqs[i].ubuf_info = NULL;
 		n->vqs[i].upend_idx = 0;
 		n->vqs[i].done_idx = 0;
+		n->vqs[i].batched_xdp = 0;
 		n->vqs[i].vhost_hlen = 0;
 		n->vqs[i].sock_hlen = 0;
 		n->vqs[i].rx_ring = NULL;
@@ -1191,6 +1364,7 @@ static int vhost_net_release(struct inode *inode, struct file *f)
 	 * since jobs can re-queue themselves. */
 	vhost_net_flush(n);
 	kfree(n->vqs[VHOST_NET_VQ_RX].rxq.queue);
+	kfree(n->vqs[VHOST_NET_VQ_TX].xdp);
 	kfree(n->dev.vqs);
 	kvfree(n);
 	return 0;