[PATCH net-next 3/3] virtio_net: Map NAPIs to queues
From: Joe Damato <hidden>
Date: 2025-01-10 20:26:23
Also in:
lkml, virtualization
Subsystem:
networking drivers, the rest, virtio net driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, "Michael S. Tsirkin", Jason Wang
Use netif_queue_set_napi to map NAPIs to queue IDs so that the mapping
can be accessed by user apps.
$ ethtool -i ens4 | grep driver
driver: virtio_net
$ sudo ethtool -L ens4 combined 4
$ ./tools/net/ynl/pyynl/cli.py \
--spec Documentation/netlink/specs/netdev.yaml \
--dump queue-get --json='{"ifindex": 2}'
[{'id': 0, 'ifindex': 2, 'napi-id': 8289, 'type': 'rx'},
{'id': 1, 'ifindex': 2, 'napi-id': 8290, 'type': 'rx'},
{'id': 2, 'ifindex': 2, 'napi-id': 8291, 'type': 'rx'},
{'id': 3, 'ifindex': 2, 'napi-id': 8292, 'type': 'rx'},
{'id': 0, 'ifindex': 2, 'type': 'tx'},
{'id': 1, 'ifindex': 2, 'type': 'tx'},
{'id': 2, 'ifindex': 2, 'type': 'tx'},
{'id': 3, 'ifindex': 2, 'type': 'tx'}]
Note that virtio_net has TX-only NAPIs which do not have NAPI IDs, so
the lack of 'napi-id' in the above output is expected.
Signed-off-by: Joe Damato <redacted>
---
drivers/net/virtio_net.c | 29 ++++++++++++++++++++++++++---
1 file changed, 26 insertions(+), 3 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 4e88d352d3eb..8f0f26cc5a94 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c@@ -2804,14 +2804,28 @@ static void virtnet_napi_do_enable(struct virtqueue *vq, } static void virtnet_napi_enable_lock(struct virtqueue *vq, - struct napi_struct *napi) + struct napi_struct *napi, + bool need_rtnl) { + struct virtnet_info *vi = vq->vdev->priv; + int q = vq2rxq(vq); + virtnet_napi_do_enable(vq, napi); + + if (q < vi->curr_queue_pairs) { + if (need_rtnl) + rtnl_lock(); + + netif_queue_set_napi(vi->dev, q, NETDEV_QUEUE_TYPE_RX, napi); + + if (need_rtnl) + rtnl_unlock(); + } } static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi) { - virtnet_napi_enable_lock(vq, napi); + virtnet_napi_enable_lock(vq, napi, false); } static void virtnet_napi_tx_enable(struct virtnet_info *vi,
@@ -2848,9 +2862,13 @@ static void refill_work(struct work_struct *work) for (i = 0; i < vi->curr_queue_pairs; i++) { struct receive_queue *rq = &vi->rq[i]; + rtnl_lock(); + netif_queue_set_napi(vi->dev, i, NETDEV_QUEUE_TYPE_RX, NULL); + rtnl_unlock(); napi_disable(&rq->napi); + still_empty = !try_fill_recv(vi, rq, GFP_KERNEL); - virtnet_napi_enable_lock(rq->vq, &rq->napi); + virtnet_napi_enable_lock(rq->vq, &rq->napi, true); /* In theory, this can happen: if we don't get any buffers in * we will *never* try to fill again.
@@ -3048,6 +3066,7 @@ static int virtnet_poll(struct napi_struct *napi, int budget) static void virtnet_disable_queue_pair(struct virtnet_info *vi, int qp_index) { virtnet_napi_tx_disable(&vi->sq[qp_index].napi); + netif_queue_set_napi(vi->dev, qp_index, NETDEV_QUEUE_TYPE_RX, NULL); napi_disable(&vi->rq[qp_index].napi); xdp_rxq_info_unreg(&vi->rq[qp_index].xdp_rxq); }
@@ -3317,8 +3336,10 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) static void virtnet_rx_pause(struct virtnet_info *vi, struct receive_queue *rq) { bool running = netif_running(vi->dev); + int q = vq2rxq(rq->vq); if (running) { + netif_queue_set_napi(vi->dev, q, NETDEV_QUEUE_TYPE_RX, NULL); napi_disable(&rq->napi); virtnet_cancel_dim(vi, &rq->dim); }
@@ -5943,6 +5964,8 @@ 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++) { + netif_queue_set_napi(vi->dev, i, NETDEV_QUEUE_TYPE_RX, + NULL); napi_disable(&vi->rq[i].napi); virtnet_napi_tx_disable(&vi->sq[i].napi); }
--
2.25.1