Re: [RFC net-next v1 08/12] virtio_net: xsk: bind/unbind xsk for tx

[Xuan Zhuo <xuanzhuo@linux.alibaba.com>]

On Tue, 24 Sep 2024 15:35:05 +0800, Jason Wang <jasowang@redhat.com> wrote:
> On Tue, Sep 24, 2024 at 9:32 AM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote:
> >
> > This patch implement the logic of bind/unbind xsk pool to sq and rq.
> >
> > Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> > ---
> >  drivers/net/virtio_net.c | 53 ++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 53 insertions(+)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index 41a5ea9b788d..7c379614fd22 100644
> > --- a/drivers/net/virtio_net.c
> > +++ b/drivers/net/virtio_net.c
> > @@ -295,6 +295,10 @@ struct send_queue {
> >
> >         /* Record whether sq is in reset state. */
> >         bool reset;
> > +
> > +       struct xsk_buff_pool *xsk_pool;
> > +
> > +       dma_addr_t xsk_hdr_dma_addr;
> >  };
> >
> >  /* Internal representation of a receive virtqueue */
> > @@ -497,6 +501,8 @@ struct virtio_net_common_hdr {
> >         };
> >  };
> >
> > +static struct virtio_net_common_hdr xsk_hdr;
> > +
> >  static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
> >  static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
> >                                struct net_device *dev,
> > @@ -5488,6 +5494,29 @@ static int virtnet_rq_bind_xsk_pool(struct virtnet_info *vi, struct receive_queu
> >         return err;
> >  }
> >
> > +static int virtnet_sq_bind_xsk_pool(struct virtnet_info *vi,
> > +                                   struct send_queue *sq,
> > +                                   struct xsk_buff_pool *pool)
> > +{
> > +       int err, qindex;
> > +
> > +       qindex = sq - vi->sq;
> > +
> > +       virtnet_tx_pause(vi, sq);
> > +
> > +       err = virtqueue_reset(sq->vq, virtnet_sq_free_unused_buf);
> > +       if (err) {
> > +               netdev_err(vi->dev, "reset tx fail: tx queue index: %d err: %d\n", qindex, err);
> > +               pool = NULL;
> > +       }
> > +
> > +       sq->xsk_pool = pool;
> > +
> > +       virtnet_tx_resume(vi, sq);
> > +
> > +       return err;
> > +}
> > +
> >  static int virtnet_xsk_pool_enable(struct net_device *dev,
> >                                    struct xsk_buff_pool *pool,
> >                                    u16 qid)
> > @@ -5496,6 +5525,7 @@ static int virtnet_xsk_pool_enable(struct net_device *dev,
> >         struct receive_queue *rq;
> >         struct device *dma_dev;
> >         struct send_queue *sq;
> > +       dma_addr_t hdr_dma;
> >         int err, size;
> >
> >         if (vi->hdr_len > xsk_pool_get_headroom(pool))
> > @@ -5533,6 +5563,11 @@ static int virtnet_xsk_pool_enable(struct net_device *dev,
> >         if (!rq->xsk_buffs)
> >                 return -ENOMEM;
> >
> > +       hdr_dma = virtqueue_dma_map_single_attrs(sq->vq, &xsk_hdr, vi->hdr_len,
> > +                                                DMA_TO_DEVICE, 0);
> > +       if (virtqueue_dma_mapping_error(sq->vq, hdr_dma))
> > +               return -ENOMEM;
> > +
> >         err = xsk_pool_dma_map(pool, dma_dev, 0);
> >         if (err)
> >                 goto err_xsk_map;
> > @@ -5541,11 +5576,24 @@ static int virtnet_xsk_pool_enable(struct net_device *dev,
> >         if (err)
> >                 goto err_rq;
> >
> > +       err = virtnet_sq_bind_xsk_pool(vi, sq, pool);
> > +       if (err)
> > +               goto err_sq;
> > +
> > +       /* Now, we do not support tx offset, so all the tx virtnet hdr is zero.
>
> What did you mean by "tx offset" here? (Or I don't see the connection
> with vnet hdr).

Sorry, should be tx offload(such as tx csum).

Will fix.

Thanks.


>
> Anyhow the patch looks good.
>
> Acked-by: Jason Wang <jasowang@redhat.com>
>
> Thanks
>