[PATCH net-next v2 3/4] virtio_net: Map NAPIs to queues
From: Joe Damato <hidden>
Date: 2025-01-16 05:53:30
Also in:
bpf, 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>
---
v2:
- Eliminate RTNL code paths using the API Jakub introduced in patch 1
of this v2.
- Added virtnet_napi_disable to reduce code duplication as
suggested by Jason Wang.
drivers/net/virtio_net.c | 34 +++++++++++++++++++++++++++++-----
1 file changed, 29 insertions(+), 5 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index cff18c66b54a..c6fda756dd07 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c@@ -2803,9 +2803,18 @@ static void virtnet_napi_do_enable(struct virtqueue *vq, local_bh_enable(); } -static void virtnet_napi_enable(struct virtqueue *vq, struct napi_struct *napi) +static void virtnet_napi_enable(struct virtqueue *vq, + struct napi_struct *napi) { + struct virtnet_info *vi = vq->vdev->priv; + int q = vq2rxq(vq); + u16 curr_qs; + virtnet_napi_do_enable(vq, napi); + + curr_qs = vi->curr_queue_pairs - vi->xdp_queue_pairs; + if (!vi->xdp_enabled || q < curr_qs) + netif_queue_set_napi(vi->dev, q, NETDEV_QUEUE_TYPE_RX, napi); } static void virtnet_napi_tx_enable(struct virtnet_info *vi,
@@ -2826,6 +2835,20 @@ static void virtnet_napi_tx_enable(struct virtnet_info *vi, virtnet_napi_do_enable(vq, napi); } +static void virtnet_napi_disable(struct virtqueue *vq, + struct napi_struct *napi) +{ + struct virtnet_info *vi = vq->vdev->priv; + int q = vq2rxq(vq); + u16 curr_qs; + + curr_qs = vi->curr_queue_pairs - vi->xdp_queue_pairs; + if (!vi->xdp_enabled || q < curr_qs) + netif_queue_set_napi(vi->dev, q, NETDEV_QUEUE_TYPE_RX, NULL); + + napi_disable(napi); +} + static void virtnet_napi_tx_disable(struct napi_struct *napi) { if (napi->weight)
@@ -2842,7 +2865,8 @@ static void refill_work(struct work_struct *work) for (i = 0; i < vi->curr_queue_pairs; i++) { struct receive_queue *rq = &vi->rq[i]; - napi_disable(&rq->napi); + virtnet_napi_disable(rq->vq, &rq->napi); + still_empty = !try_fill_recv(vi, rq, GFP_KERNEL); virtnet_napi_enable(rq->vq, &rq->napi);
@@ -3042,7 +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); - napi_disable(&vi->rq[qp_index].napi); + virtnet_napi_disable(vi->rq[qp_index].vq, &vi->rq[qp_index].napi); xdp_rxq_info_unreg(&vi->rq[qp_index].xdp_rxq); }
@@ -3313,7 +3337,7 @@ static void virtnet_rx_pause(struct virtnet_info *vi, struct receive_queue *rq) bool running = netif_running(vi->dev); if (running) { - napi_disable(&rq->napi); + virtnet_napi_disable(rq->vq, &rq->napi); virtnet_cancel_dim(vi, &rq->dim); } }
@@ -5932,7 +5956,7 @@ 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++) { - napi_disable(&vi->rq[i].napi); + virtnet_napi_disable(vi->rq[i].vq, &vi->rq[i].napi); virtnet_napi_tx_disable(&vi->sq[i].napi); } }
--
2.25.1