Re: [PATCH net-next 3/8] virtio_net: introduce virtnet_xdp_handler() to seprate the logic of run xdp

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, Mar 28, 2023 at 8:04 PM Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> wrote:
>
> At present, we have two similar logic to perform the XDP prog.
>
> Therefore, this PATCH separates the code of executing XDP, which is
> conducive to later maintenance.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
> ---
>  drivers/net/virtio_net.c | 142 +++++++++++++++++++++------------------
>  1 file changed, 75 insertions(+), 67 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index bb426958cdd4..72b9d6ee4024 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -301,6 +301,15 @@ struct padded_vnet_hdr {
>         char padding[12];
>  };
>
> +enum {
> +       /* xdp pass */
> +       VIRTNET_XDP_RES_PASS,
> +       /* drop packet. the caller needs to release the page. */
> +       VIRTNET_XDP_RES_DROP,
> +       /* packet is consumed by xdp. the caller needs to do nothing. */
> +       VIRTNET_XDP_RES_CONSUMED,
> +};

I'd prefer this to be done on top unless it is a must. But I don't see
any advantage of introducing this, it's partial mapping of XDP action
and it needs to be extended when XDP action is extended. (And we've
already had: VIRTIO_XDP_REDIR and VIRTIO_XDP_TX ...)

> +
>  static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf);
>  static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
>
> @@ -789,6 +798,59 @@ static int virtnet_xdp_xmit(struct net_device *dev,
>         return ret;
>  }
>
> +static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
> +                              struct net_device *dev,
> +                              unsigned int *xdp_xmit,
> +                              struct virtnet_rq_stats *stats)
> +{
> +       struct xdp_frame *xdpf;
> +       int err;
> +       u32 act;
> +
> +       act = bpf_prog_run_xdp(xdp_prog, xdp);
> +       stats->xdp_packets++;
> +
> +       switch (act) {
> +       case XDP_PASS:
> +               return VIRTNET_XDP_RES_PASS;
> +
> +       case XDP_TX:
> +               stats->xdp_tx++;
> +               xdpf = xdp_convert_buff_to_frame(xdp);
> +               if (unlikely(!xdpf))
> +                       return VIRTNET_XDP_RES_DROP;
> +
> +               err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
> +               if (unlikely(!err)) {
> +                       xdp_return_frame_rx_napi(xdpf);
> +               } else if (unlikely(err < 0)) {
> +                       trace_xdp_exception(dev, xdp_prog, act);
> +                       return VIRTNET_XDP_RES_DROP;
> +               }
> +
> +               *xdp_xmit |= VIRTIO_XDP_TX;
> +               return VIRTNET_XDP_RES_CONSUMED;
> +
> +       case XDP_REDIRECT:
> +               stats->xdp_redirects++;
> +               err = xdp_do_redirect(dev, xdp, xdp_prog);
> +               if (err)
> +                       return VIRTNET_XDP_RES_DROP;
> +
> +               *xdp_xmit |= VIRTIO_XDP_REDIR;
> +               return VIRTNET_XDP_RES_CONSUMED;
> +
> +       default:
> +               bpf_warn_invalid_xdp_action(dev, xdp_prog, act);
> +               fallthrough;
> +       case XDP_ABORTED:
> +               trace_xdp_exception(dev, xdp_prog, act);
> +               fallthrough;
> +       case XDP_DROP:
> +               return VIRTNET_XDP_RES_DROP;
> +       }
> +}
> +
>  static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
>  {
>         return vi->xdp_enabled ? VIRTIO_XDP_HEADROOM : 0;
> @@ -876,7 +938,6 @@ static struct sk_buff *receive_small(struct net_device *dev,
>         struct page *page = virt_to_head_page(buf);
>         unsigned int delta = 0;
>         struct page *xdp_page;
> -       int err;
>         unsigned int metasize = 0;
>
>         len -= vi->hdr_len;
> @@ -898,7 +959,6 @@ static struct sk_buff *receive_small(struct net_device *dev,
>         xdp_prog = rcu_dereference(rq->xdp_prog);
>         if (xdp_prog) {
>                 struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset;
> -               struct xdp_frame *xdpf;
>                 struct xdp_buff xdp;
>                 void *orig_data;
>                 u32 act;
> @@ -931,46 +991,22 @@ static struct sk_buff *receive_small(struct net_device *dev,
>                 xdp_prepare_buff(&xdp, buf + VIRTNET_RX_PAD + vi->hdr_len,
>                                  xdp_headroom, len, true);
>                 orig_data = xdp.data;
> -               act = bpf_prog_run_xdp(xdp_prog, &xdp);
> -               stats->xdp_packets++;
> +
> +               act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats);
>
>                 switch (act) {
> -               case XDP_PASS:
> +               case VIRTNET_XDP_RES_PASS:
>                         /* Recalculate length in case bpf program changed it */
>                         delta = orig_data - xdp.data;
>                         len = xdp.data_end - xdp.data;
>                         metasize = xdp.data - xdp.data_meta;
>                         break;
> -               case XDP_TX:
> -                       stats->xdp_tx++;
> -                       xdpf = xdp_convert_buff_to_frame(&xdp);
> -                       if (unlikely(!xdpf))
> -                               goto err_xdp;
> -                       err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
> -                       if (unlikely(!err)) {
> -                               xdp_return_frame_rx_napi(xdpf);
> -                       } else if (unlikely(err < 0)) {
> -                               trace_xdp_exception(vi->dev, xdp_prog, act);
> -                               goto err_xdp;
> -                       }
> -                       *xdp_xmit |= VIRTIO_XDP_TX;
> -                       rcu_read_unlock();
> -                       goto xdp_xmit;
> -               case XDP_REDIRECT:
> -                       stats->xdp_redirects++;
> -                       err = xdp_do_redirect(dev, &xdp, xdp_prog);
> -                       if (err)
> -                               goto err_xdp;
> -                       *xdp_xmit |= VIRTIO_XDP_REDIR;
> +
> +               case VIRTNET_XDP_RES_CONSUMED:
>                         rcu_read_unlock();
>                         goto xdp_xmit;
> -               default:
> -                       bpf_warn_invalid_xdp_action(vi->dev, xdp_prog, act);
> -                       fallthrough;
> -               case XDP_ABORTED:
> -                       trace_xdp_exception(vi->dev, xdp_prog, act);
> -                       goto err_xdp;
> -               case XDP_DROP:
> +
> +               case VIRTNET_XDP_RES_DROP:
>                         goto err_xdp;
>                 }
>         }
> @@ -1277,7 +1313,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
>         if (xdp_prog) {
>                 unsigned int xdp_frags_truesz = 0;
>                 struct skb_shared_info *shinfo;
> -               struct xdp_frame *xdpf;
>                 struct page *xdp_page;
>                 struct xdp_buff xdp;
>                 void *data;
> @@ -1294,49 +1329,22 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
>                 if (unlikely(err))
>                         goto err_xdp_frags;
>
> -               act = bpf_prog_run_xdp(xdp_prog, &xdp);
> -               stats->xdp_packets++;
> +               act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats);
>
>                 switch (act) {
> -               case XDP_PASS:
> +               case VIRTNET_XDP_RES_PASS:
>                         head_skb = build_skb_from_xdp_buff(dev, vi, &xdp, xdp_frags_truesz);
>                         if (unlikely(!head_skb))
>                                 goto err_xdp_frags;
>
>                         rcu_read_unlock();
>                         return head_skb;
> -               case XDP_TX:
> -                       stats->xdp_tx++;
> -                       xdpf = xdp_convert_buff_to_frame(&xdp);
> -                       if (unlikely(!xdpf)) {
> -                               netdev_dbg(dev, "convert buff to frame failed for xdp\n");

Nit: This debug is lost after the conversion.

Thanks

> -                               goto err_xdp_frags;
> -                       }
> -                       err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
> -                       if (unlikely(!err)) {
> -                               xdp_return_frame_rx_napi(xdpf);
> -                       } else if (unlikely(err < 0)) {
> -                               trace_xdp_exception(vi->dev, xdp_prog, act);
> -                               goto err_xdp_frags;
> -                       }
> -                       *xdp_xmit |= VIRTIO_XDP_TX;
> -                       rcu_read_unlock();
> -                       goto xdp_xmit;
> -               case XDP_REDIRECT:
> -                       stats->xdp_redirects++;
> -                       err = xdp_do_redirect(dev, &xdp, xdp_prog);
> -                       if (err)
> -                               goto err_xdp_frags;
> -                       *xdp_xmit |= VIRTIO_XDP_REDIR;
> +
> +               case VIRTNET_XDP_RES_CONSUMED:
>                         rcu_read_unlock();
>                         goto xdp_xmit;
> -               default:
> -                       bpf_warn_invalid_xdp_action(vi->dev, xdp_prog, act);
> -                       fallthrough;
> -               case XDP_ABORTED:
> -                       trace_xdp_exception(vi->dev, xdp_prog, act);
> -                       fallthrough;
> -               case XDP_DROP:
> +
> +               case VIRTNET_XDP_RES_DROP:
>                         goto err_xdp_frags;
>                 }
>  err_xdp_frags:
> --
> 2.32.0.3.g01195cf9f
>

_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization




[Index of Archives]     [KVM Development]     [Libvirt Development]     [Libvirt Users]     [CentOS Virtualization]     [Netdev]     [Ethernet Bridging]     [Linux Wireless]     [Kernel Newbies]     [Security]     [Linux for Hams]     [Netfilter]     [Bugtraq]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux Admin]     [Samba]

  Powered by Linux