On Thu, 16 Jan 2025 05:52:58 +0000, Joe Damato <jdam...@fastly.com> wrote:
> 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 <jdam...@fastly.com>
> ---
> 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);
So what case the check of xdp_enabled is for?
And I think we should merge this to last commit.
Thanks.
> }
>
> 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
>
