[PATCH net-next v2 13/21] virtio_net: xsk: tx: support wakeup

Xuan Zhuo
Tue, 07 Nov 2023 03:12:19 -0000

xsk wakeup is used to trigger the logic for xsk xmit by xsk framework or
user.

Virtio-net does not support to actively generate an interruption, so it
tries to trigger tx NAPI on the local cpu.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/net/virtio/main.c       | 20 ++++++--------------
 drivers/net/virtio/virtio_net.h |  9 +++++++++
 drivers/net/virtio/xsk.c        | 23 +++++++++++++++++++++++
 drivers/net/virtio/xsk.h        |  1 +
 4 files changed, 39 insertions(+), 14 deletions(-)

diff --git a/drivers/net/virtio/main.c b/drivers/net/virtio/main.c
index ff6bc764089d..6a5e74c482f3 100644
--- a/drivers/net/virtio/main.c
+++ b/drivers/net/virtio/main.c
@@ -233,15 +233,6 @@ static void disable_delayed_refill(struct virtnet_info *vi)
 	spin_unlock_bh(&vi->refill_lock);
 }

-static void virtqueue_napi_schedule(struct napi_struct *napi,
-				    struct virtqueue *vq)
-{
-	if (napi_schedule_prep(napi)) {
-		virtqueue_disable_cb(vq);
-		__napi_schedule(napi);
-	}
-}
-
 static void virtqueue_napi_complete(struct napi_struct *napi,
 				    struct virtqueue *vq, int processed)
 {
@@ -250,7 +241,7 @@ static void virtqueue_napi_complete(struct napi_struct
*napi,
 	opaque = virtqueue_enable_cb_prepare(vq);
 	if (napi_complete_done(napi, processed)) {
 		if (unlikely(virtqueue_poll(vq, opaque)))
-			virtqueue_napi_schedule(napi, vq);
+			virtnet_vq_napi_schedule(napi, vq);
 	} else {
 		virtqueue_disable_cb(vq);
 	}
@@ -265,7 +256,7 @@ static void skb_xmit_done(struct virtqueue *vq)
 	virtqueue_disable_cb(vq);

 	if (napi->weight)
-		virtqueue_napi_schedule(napi, vq);
+		virtnet_vq_napi_schedule(napi, vq);
 	else
 		/* We were probably waiting for more output buffers. */
 		netif_wake_subqueue(vi->dev, vq2txq(vq));
@@ -667,7 +658,7 @@ static void check_sq_full_and_disable(struct virtnet_info
*vi,
 		netif_stop_subqueue(dev, qnum);
 		if (use_napi) {
 			if (unlikely(!virtqueue_enable_cb_delayed(sq->vq)))
-				virtqueue_napi_schedule(&sq->napi, sq->vq);
+				virtnet_vq_napi_schedule(&sq->napi, sq->vq);
 		} else if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {
 			/* More just got used, free them then recheck. */
 			free_old_xmit(sq, false);
@@ -1834,7 +1825,7 @@ static void skb_recv_done(struct virtqueue *rvq)
 	struct virtnet_info *vi = rvq->vdev->priv;
 	struct virtnet_rq *rq = &vi->rq[vq2rxq(rvq)];

-	virtqueue_napi_schedule(&rq->napi, rvq);
+	virtnet_vq_napi_schedule(&rq->napi, rvq);
 }

 static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi)
@@ -1846,7 +1837,7 @@ static void virtnet_napi_enable(struct virtqueue *vq,
struct napi_struct *napi)
 	 * Call local_bh_enable after to trigger softIRQ processing.
 	 */
 	local_bh_disable();
-	virtqueue_napi_schedule(napi, vq);
+	virtnet_vq_napi_schedule(napi, vq);
 	local_bh_enable();
 }

@@ -3818,6 +3809,7 @@ static const struct net_device_ops virtnet_netdev = {
 	.ndo_vlan_rx_kill_vid = virtnet_vlan_rx_kill_vid,
 	.ndo_bpf		= virtnet_xdp,
 	.ndo_xdp_xmit		= virtnet_xdp_xmit,
+	.ndo_xsk_wakeup         = virtnet_xsk_wakeup,
 	.ndo_features_check	= passthru_features_check,
 	.ndo_get_phys_port_name	= virtnet_get_phys_port_name,
 	.ndo_set_features	= virtnet_set_features,
diff --git a/drivers/net/virtio/virtio_net.h b/drivers/net/virtio/virtio_net.h
index 1c21af47e13c..a431a2c1ee47 100644
--- a/drivers/net/virtio/virtio_net.h
+++ b/drivers/net/virtio/virtio_net.h
@@ -302,6 +302,15 @@ static inline bool virtnet_is_xdp_raw_buffer_queue(struct
virtnet_info *vi, int
 		return false;
 }

+static inline void virtnet_vq_napi_schedule(struct napi_struct *napi,
+					    struct virtqueue *vq)
+{
+	if (napi_schedule_prep(napi)) {
+		virtqueue_disable_cb(vq);
+		__napi_schedule(napi);
+	}
+}
+
 void virtnet_rx_pause(struct virtnet_info *vi, struct virtnet_rq *rq);
 void virtnet_rx_resume(struct virtnet_info *vi, struct virtnet_rq *rq);
 void virtnet_tx_pause(struct virtnet_info *vi, struct virtnet_sq *sq);
diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c
index caa448308232..ea5804ddd44e 100644
--- a/drivers/net/virtio/xsk.c
+++ b/drivers/net/virtio/xsk.c
@@ -117,6 +117,29 @@ bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct
xsk_buff_pool *pool,
 	return sent == budget;
 }

+int virtnet_xsk_wakeup(struct net_device *dev, u32 qid, u32 flag)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+	struct virtnet_sq *sq;
+
+	if (!netif_running(dev))
+		return -ENETDOWN;
+
+	if (qid >= vi->curr_queue_pairs)
+		return -EINVAL;
+
+	sq = &vi->sq[qid];
+
+	if (napi_if_scheduled_mark_missed(&sq->napi))
+		return 0;
+
+	local_bh_disable();
+	virtnet_vq_napi_schedule(&sq->napi, sq->vq);
+	local_bh_enable();
+
+	return 0;
+}
+
 static int virtnet_rq_bind_xsk_pool(struct virtnet_info *vi, struct virtnet_rq
*rq,
 				    struct xsk_buff_pool *pool)
 {
diff --git a/drivers/net/virtio/xsk.h b/drivers/net/virtio/xsk.h
index 73ca8cd5308b..1bd19dcda649 100644
--- a/drivers/net/virtio/xsk.h
+++ b/drivers/net/virtio/xsk.h
@@ -17,4 +17,5 @@ static inline void *virtnet_xsk_to_ptr(u32 len)
 int virtnet_xsk_pool_setup(struct net_device *dev, struct netdev_bpf *xdp);
 bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct xsk_buff_pool *pool,
 		      int budget);
+int virtnet_xsk_wakeup(struct net_device *dev, u32 qid, u32 flag);
 #endif
--
2.32.0.3.g01195cf9f