1 files changed, 129 insertions, 52 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 023725086046..4cfceb789eea 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -57,6 +57,8 @@ module_param(napi_tx, bool, 0644);
 #define VIRTIO_XDP_TX		BIT(0)
 #define VIRTIO_XDP_REDIR	BIT(1)
 
+#define VIRTIO_XDP_FLAG	BIT(0)
+
 /* RX packet size EWMA. The average packet size is used to determine the packet
  * buffer size when refilling RX rings. As the entire RX ring may be refilled
  * at once, the weight is chosen so that the EWMA will be insensitive to short-
@@ -252,6 +254,21 @@ struct padded_vnet_hdr {
 	char padding[4];
 };
 
+static bool is_xdp_frame(void *ptr)
+{
+	return (unsigned long)ptr & VIRTIO_XDP_FLAG;
+}
+
+static void *xdp_to_ptr(struct xdp_frame *ptr)
+{
+	return (void *)((unsigned long)ptr | VIRTIO_XDP_FLAG);
+}
+
+static struct xdp_frame *ptr_to_xdp(void *ptr)
+{
+	return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG);
+}
+
 /* Converting between virtqueue no. and kernel tx/rx queue no.
  * 0:rx0 1:tx0 2:rx1 3:tx1 ... 2N:rxN 2N+1:txN 2N+2:cvq
  */
@@ -462,7 +479,8 @@ static int __virtnet_xdp_xmit_one(struct virtnet_info *vi,
 
 	sg_init_one(sq->sg, xdpf->data, xdpf->len);
 
-	err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdpf, GFP_ATOMIC);
+	err = virtqueue_add_outbuf(sq->vq, sq->sg, 1, xdp_to_ptr(xdpf),
+				   GFP_ATOMIC);
 	if (unlikely(err))
 		return -ENOSPC; /* Caller handle free/refcnt */
 
@@ -482,36 +500,47 @@ static int virtnet_xdp_xmit(struct net_device *dev,
 {
 	struct virtnet_info *vi = netdev_priv(dev);
 	struct receive_queue *rq = vi->rq;
-	struct xdp_frame *xdpf_sent;
 	struct bpf_prog *xdp_prog;
 	struct send_queue *sq;
 	unsigned int len;
+	int packets = 0;
+	int bytes = 0;
 	int drops = 0;
 	int kicks = 0;
 	int ret, err;
+	void *ptr;
 	int i;
 
-	sq = virtnet_xdp_sq(vi);
-
-	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
-		ret = -EINVAL;
-		drops = n;
-		goto out;
-	}
-
 	/* Only allow ndo_xdp_xmit if XDP is loaded on dev, as this
 	 * indicate XDP resources have been successfully allocated.
 	 */
 	xdp_prog = rcu_dereference(rq->xdp_prog);
-	if (!xdp_prog) {
-		ret = -ENXIO;
+	if (!xdp_prog)
+		return -ENXIO;
+
+	sq = virtnet_xdp_sq(vi);
+
+	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) {
+		ret = -EINVAL;
 		drops = n;
 		goto out;
 	}
 
 	/* Free up any pending old buffers before queueing new ones. */
-	while ((xdpf_sent = virtqueue_get_buf(sq->vq, &len)) != NULL)
-		xdp_return_frame(xdpf_sent);
+	while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
+		if (likely(is_xdp_frame(ptr))) {
+			struct xdp_frame *frame = ptr_to_xdp(ptr);
+
+			bytes += frame->len;
+			xdp_return_frame(frame);
+		} else {
+			struct sk_buff *skb = ptr;
+
+			bytes += skb->len;
+			napi_consume_skb(skb, false);
+		}
+		packets++;
+	}
 
 	for (i = 0; i < n; i++) {
 		struct xdp_frame *xdpf = frames[i];
@@ -530,6 +559,8 @@ static int virtnet_xdp_xmit(struct net_device *dev,
 	}
 out:
 	u64_stats_update_begin(&sq->stats.syncp);
+	sq->stats.bytes += bytes;
+	sq->stats.packets += packets;
 	sq->stats.xdp_tx += n;
 	sq->stats.xdp_tx_drops += drops;
 	sq->stats.kicks += kicks;
@@ -1330,20 +1361,28 @@ static int virtnet_receive(struct receive_queue *rq, int budget,
 	return stats.packets;
 }
 
-static void free_old_xmit_skbs(struct send_queue *sq)
+static void free_old_xmit_skbs(struct send_queue *sq, bool in_napi)
 {
-	struct sk_buff *skb;
 	unsigned int len;
 	unsigned int packets = 0;
 	unsigned int bytes = 0;
+	void *ptr;
 
-	while ((skb = virtqueue_get_buf(sq->vq, &len)) != NULL) {
-		pr_debug("Sent skb %p\n", skb);
+	while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
+		if (likely(!is_xdp_frame(ptr))) {
+			struct sk_buff *skb = ptr;
 
-		bytes += skb->len;
-		packets++;
+			pr_debug("Sent skb %p\n", skb);
+
+			bytes += skb->len;
+			napi_consume_skb(skb, in_napi);
+		} else {
+			struct xdp_frame *frame = ptr_to_xdp(ptr);
 
-		dev_consume_skb_any(skb);
+			bytes += frame->len;
+			xdp_return_frame(frame);
+		}
+		packets++;
 	}
 
 	/* Avoid overhead when no packets have been processed
@@ -1358,6 +1397,16 @@ static void free_old_xmit_skbs(struct send_queue *sq)
 	u64_stats_update_end(&sq->stats.syncp);
 }
 
+static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
+{
+	if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
+		return false;
+	else if (q < vi->curr_queue_pairs)
+		return true;
+	else
+		return false;
+}
+
 static void virtnet_poll_cleantx(struct receive_queue *rq)
 {
 	struct virtnet_info *vi = rq->vq->vdev->priv;
@@ -1365,11 +1414,11 @@ static void virtnet_poll_cleantx(struct receive_queue *rq)
 	struct send_queue *sq = &vi->sq[index];
 	struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, index);
 
-	if (!sq->napi.weight)
+	if (!sq->napi.weight || is_xdp_raw_buffer_queue(vi, index))
 		return;
 
 	if (__netif_tx_trylock(txq)) {
-		free_old_xmit_skbs(sq);
+		free_old_xmit_skbs(sq, true);
 		__netif_tx_unlock(txq);
 	}
 
@@ -1442,10 +1491,18 @@ static int virtnet_poll_tx(struct napi_struct *napi, int budget)
 {
 	struct send_queue *sq = container_of(napi, struct send_queue, napi);
 	struct virtnet_info *vi = sq->vq->vdev->priv;
-	struct netdev_queue *txq = netdev_get_tx_queue(vi->dev, vq2txq(sq->vq));
+	unsigned int index = vq2txq(sq->vq);
+	struct netdev_queue *txq;
 
+	if (unlikely(is_xdp_raw_buffer_queue(vi, index))) {
+		/* We don't need to enable cb for XDP */
+		napi_complete_done(napi, 0);
+		return 0;
+	}
+
+	txq = netdev_get_tx_queue(vi->dev, index);
 	__netif_tx_lock(txq, raw_smp_processor_id());
-	free_old_xmit_skbs(sq);
+	free_old_xmit_skbs(sq, true);
 	__netif_tx_unlock(txq);
 
 	virtqueue_napi_complete(napi, sq->vq, 0);
@@ -1514,7 +1571,7 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 	bool use_napi = sq->napi.weight;
 
 	/* Free up any pending old buffers before queueing new ones. */
-	free_old_xmit_skbs(sq);
+	free_old_xmit_skbs(sq, false);
 
 	if (use_napi && kick)
 		virtqueue_enable_cb_delayed(sq->vq);
@@ -1557,7 +1614,7 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
 		if (!use_napi &&
 		    unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
 			/* More just got used, free them then recheck. */
-			free_old_xmit_skbs(sq);
+			free_old_xmit_skbs(sq, false);
 			if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) {
 				netif_start_subqueue(dev, qnum);
 				virtqueue_disable_cb(sq->vq);
@@ -2395,6 +2452,10 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
 		return -ENOMEM;
 	}
 
+	old_prog = rtnl_dereference(vi->rq[0].xdp_prog);
+	if (!prog && !old_prog)
+		return 0;
+
 	if (prog) {
 		prog = bpf_prog_add(prog, vi->max_queue_pairs - 1);
 		if (IS_ERR(prog))
@@ -2402,36 +2463,62 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
 	}
 
 	/* Make sure NAPI is not using any XDP TX queues for RX. */
-	if (netif_running(dev))
-		for (i = 0; i < vi->max_queue_pairs; i++)
+	if (netif_running(dev)) {
+		for (i = 0; i < vi->max_queue_pairs; i++) {
 			napi_disable(&vi->rq[i].napi);
+			virtnet_napi_tx_disable(&vi->sq[i].napi);
+		}
+	}
+
+	if (!prog) {
+		for (i = 0; i < vi->max_queue_pairs; i++) {
+			rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
+			if (i == 0)
+				virtnet_restore_guest_offloads(vi);
+		}
+		synchronize_net();
+	}
 
-	netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
 	err = _virtnet_set_queues(vi, curr_qp + xdp_qp);
 	if (err)
 		goto err;
+	netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
 	vi->xdp_queue_pairs = xdp_qp;
 
-	for (i = 0; i < vi->max_queue_pairs; i++) {
-		old_prog = rtnl_dereference(vi->rq[i].xdp_prog);
-		rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
-		if (i == 0) {
-			if (!old_prog)
+	if (prog) {
+		for (i = 0; i < vi->max_queue_pairs; i++) {
+			rcu_assign_pointer(vi->rq[i].xdp_prog, prog);
+			if (i == 0 && !old_prog)
 				virtnet_clear_guest_offloads(vi);
-			if (!prog)
-				virtnet_restore_guest_offloads(vi);
 		}
+	}
+
+	for (i = 0; i < vi->max_queue_pairs; i++) {
 		if (old_prog)
 			bpf_prog_put(old_prog);
-		if (netif_running(dev))
+		if (netif_running(dev)) {
 			virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
+			virtnet_napi_tx_enable(vi, vi->sq[i].vq,
+					       &vi->sq[i].napi);
+		}
 	}
 
 	return 0;
 
 err:
-	for (i = 0; i < vi->max_queue_pairs; i++)
-		virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
+	if (!prog) {
+		virtnet_clear_guest_offloads(vi);
+		for (i = 0; i < vi->max_queue_pairs; i++)
+			rcu_assign_pointer(vi->rq[i].xdp_prog, old_prog);
+	}
+
+	if (netif_running(dev)) {
+		for (i = 0; i < vi->max_queue_pairs; i++) {
+			virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
+			virtnet_napi_tx_enable(vi, vi->sq[i].vq,
+					       &vi->sq[i].napi);
+		}
+	}
 	if (prog)
 		bpf_prog_sub(prog, vi->max_queue_pairs - 1);
 	return err;
@@ -2613,16 +2700,6 @@ static void free_receive_page_frags(struct virtnet_info *vi)
 			put_page(vi->rq[i].alloc_frag.page);
 }
 
-static bool is_xdp_raw_buffer_queue(struct virtnet_info *vi, int q)
-{
-	if (q < (vi->curr_queue_pairs - vi->xdp_queue_pairs))
-		return false;
-	else if (q < vi->curr_queue_pairs)
-		return true;
-	else
-		return false;
-}
-
 static void free_unused_bufs(struct virtnet_info *vi)
 {
 	void *buf;
@@ -2631,10 +2708,10 @@ static void free_unused_bufs(struct virtnet_info *vi)
 	for (i = 0; i < vi->max_queue_pairs; i++) {
 		struct virtqueue *vq = vi->sq[i].vq;
 		while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
-			if (!is_xdp_raw_buffer_queue(vi, i))
+			if (!is_xdp_frame(buf))
 				dev_kfree_skb(buf);
 			else
-				put_page(virt_to_head_page(buf));
+				xdp_return_frame(ptr_to_xdp(buf));
 		}
 	}