[PATCH net-next v3 7/8] virtio-net: poll tx call xsk zerocopy xmit

[Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>]

poll tx call virtnet_xsk_run, then the data in the xsk tx queue will be
continuously consumed by napi.

Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
Reviewed-by: Dust Li <dust.li@xxxxxxxxxxxxxxxxx>
---
 drivers/net/virtio_net.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index d7e95f55478d..fac7d0020013 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -264,6 +264,9 @@ struct padded_vnet_hdr {
 	char padding[4];
 };
 
+static int virtnet_xsk_run(struct send_queue *sq, struct xsk_buff_pool *pool,
+			   int budget, bool in_napi);
+
 static bool is_xdp_frame(void *ptr)
 {
 	return (unsigned long)ptr & VIRTIO_XDP_FLAG;
@@ -1553,7 +1556,9 @@ 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;
 	unsigned int index = vq2txq(sq->vq);
+	struct xsk_buff_pool *pool;
 	struct netdev_queue *txq;
+	int work = 0;
 
 	if (unlikely(is_xdp_raw_buffer_queue(vi, index))) {
 		/* We don't need to enable cb for XDP */
@@ -1563,15 +1568,24 @@ static int virtnet_poll_tx(struct napi_struct *napi, int budget)
 
 	txq = netdev_get_tx_queue(vi->dev, index);
 	__netif_tx_lock(txq, raw_smp_processor_id());
-	free_old_xmit_skbs(sq, true);
+	rcu_read_lock();
+	pool = rcu_dereference(sq->xsk.pool);
+	if (pool) {
+		work = virtnet_xsk_run(sq, pool, budget, true);
+		rcu_read_unlock();
+	} else {
+		rcu_read_unlock();
+		free_old_xmit_skbs(sq, true);
+	}
 	__netif_tx_unlock(txq);
 
-	virtqueue_napi_complete(napi, sq->vq, 0);
+	if (work < budget)
+		virtqueue_napi_complete(napi, sq->vq, 0);
 
 	if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS)
 		netif_tx_wake_queue(txq);
 
-	return 0;
+	return work;
 }
 
 static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
-- 
2.31.0