1 files changed, 93 insertions, 7 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 1d16862c5710..ca3d2e2350c6 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -330,12 +330,58 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
 	return skb;
 }
 
+static void virtnet_xdp_xmit(struct virtnet_info *vi,
+			     struct receive_queue *rq,
+			     struct send_queue *sq,
+			     struct xdp_buff *xdp)
+{
+	struct page *page = virt_to_head_page(xdp->data);
+	struct virtio_net_hdr_mrg_rxbuf *hdr;
+	unsigned int num_sg, len;
+	void *xdp_sent;
+	int err;
+
+	/* Free up any pending old buffers before queueing new ones. */
+	while ((xdp_sent = virtqueue_get_buf(sq->vq, &len)) != NULL) {
+		struct page *sent_page = virt_to_head_page(xdp_sent);
+
+		if (vi->mergeable_rx_bufs)
+			put_page(sent_page);
+		else
+			give_pages(rq, sent_page);
+	}
+
+	/* Zero header and leave csum up to XDP layers */
+	hdr = xdp->data;
+	memset(hdr, 0, vi->hdr_len);
+
+	num_sg = 1;
+	sg_init_one(sq->sg, xdp->data, xdp->data_end - xdp->data);
+	err = virtqueue_add_outbuf(sq->vq, sq->sg, num_sg,
+				   xdp->data, GFP_ATOMIC);
+	if (unlikely(err)) {
+		if (vi->mergeable_rx_bufs)
+			put_page(page);
+		else
+			give_pages(rq, page);
+		return; // On error abort to avoid unnecessary kick
+	} else if (!vi->mergeable_rx_bufs) {
+		/* If not mergeable bufs must be big packets so cleanup pages */
+		give_pages(rq, (struct page *)page->private);
+		page->private = 0;
+	}
+
+	virtqueue_kick(sq->vq);
+}
+
 static u32 do_xdp_prog(struct virtnet_info *vi,
+		       struct receive_queue *rq,
 		       struct bpf_prog *xdp_prog,
 		       struct page *page, int offset, int len)
 {
 	int hdr_padded_len;
 	struct xdp_buff xdp;
+	unsigned int qp;
 	u32 act;
 	u8 *buf;
 
@@ -353,9 +399,15 @@ static u32 do_xdp_prog(struct virtnet_info *vi,
 	switch (act) {
 	case XDP_PASS:
 		return XDP_PASS;
+	case XDP_TX:
+		qp = vi->curr_queue_pairs -
+			vi->xdp_queue_pairs +
+			smp_processor_id();
+		xdp.data = buf + (vi->mergeable_rx_bufs ? 0 : 4);
+		virtnet_xdp_xmit(vi, rq, &vi->sq[qp], &xdp);
+		return XDP_TX;
 	default:
 		bpf_warn_invalid_xdp_action(act);
-	case XDP_TX:
 	case XDP_ABORTED:
 	case XDP_DROP:
 		return XDP_DROP;
@@ -390,9 +442,17 @@ static struct sk_buff *receive_big(struct net_device *dev,
 
 		if (unlikely(hdr->hdr.gso_type || hdr->hdr.flags))
 			goto err_xdp;
-		act = do_xdp_prog(vi, xdp_prog, page, 0, len);
-		if (act == XDP_DROP)
+		act = do_xdp_prog(vi, rq, xdp_prog, page, 0, len);
+		switch (act) {
+		case XDP_PASS:
+			break;
+		case XDP_TX:
+			rcu_read_unlock();
+			goto xdp_xmit;
+		case XDP_DROP:
+		default:
 			goto err_xdp;
+		}
 	}
 	rcu_read_unlock();
 
@@ -407,6 +467,7 @@ err_xdp:
 err:
 	dev->stats.rx_dropped++;
 	give_pages(rq, page);
+xdp_xmit:
 	return NULL;
 }
 
@@ -425,6 +486,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
 	struct bpf_prog *xdp_prog;
 	unsigned int truesize;
 
+	head_skb = NULL;
+
 	rcu_read_lock();
 	xdp_prog = rcu_dereference(rq->xdp_prog);
 	if (xdp_prog) {
@@ -448,9 +511,17 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
 		if (unlikely(hdr->hdr.gso_type || hdr->hdr.flags))
 			goto err_xdp;
 
-		act = do_xdp_prog(vi, xdp_prog, page, offset, len);
-		if (act == XDP_DROP)
+		act = do_xdp_prog(vi, rq, xdp_prog, page, offset, len);
+		switch (act) {
+		case XDP_PASS:
+			break;
+		case XDP_TX:
+			rcu_read_unlock();
+			goto xdp_xmit;
+		case XDP_DROP:
+		default:
 			goto err_xdp;
+		}
 	}
 	rcu_read_unlock();
 
@@ -528,6 +599,7 @@ err_skb:
 err_buf:
 	dev->stats.rx_dropped++;
 	dev_kfree_skb(head_skb);
+xdp_xmit:
 	return NULL;
 }
 
@@ -1713,6 +1785,16 @@ static void free_receive_page_frags(struct virtnet_info *vi)
 			put_page(vi->rq[i].alloc_frag.page);
 }
 
+static bool is_xdp_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;
@@ -1720,8 +1802,12 @@ 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)
-			dev_kfree_skb(buf);
+		while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
+			if (!is_xdp_queue(vi, i))
+				dev_kfree_skb(buf);
+			else
+				put_page(virt_to_head_page(buf));
+		}
 	}
 
 	for (i = 0; i < vi->max_queue_pairs; i++) {