On Thu, 30 Mar 2023 12:18:15 +0200, Paolo Abeni <[email protected]> wrote: > Hi, > > On Tue, 2023-03-28 at 20:04 +0800, Xuan Zhuo wrote: > > The purpose of this patch is to simplify the receive_mergeable(). > > Separate all the logic of XDP into a function. > > > > Signed-off-by: Xuan Zhuo <[email protected]> > > --- > > drivers/net/virtio_net.c | 128 +++++++++++++++++++++++---------------- > > 1 file changed, 76 insertions(+), 52 deletions(-) > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > > index 136131a7868a..c8978d8d8adb 100644 > > --- a/drivers/net/virtio_net.c > > +++ b/drivers/net/virtio_net.c > > @@ -1316,6 +1316,63 @@ static void *mergeable_xdp_prepare(struct > > virtnet_info *vi, > > return page_address(xdp_page) + VIRTIO_XDP_HEADROOM; > > } > > > > +static struct sk_buff *receive_mergeable_xdp(struct net_device *dev, > > + struct virtnet_info *vi, > > + struct receive_queue *rq, > > + struct bpf_prog *xdp_prog, > > + void *buf, > > + void *ctx, > > + unsigned int len, > > + unsigned int *xdp_xmit, > > + struct virtnet_rq_stats *stats) > > +{ > > + struct virtio_net_hdr_mrg_rxbuf *hdr = buf; > > + int num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers); > > + struct page *page = virt_to_head_page(buf); > > + int offset = buf - page_address(page); > > + unsigned int xdp_frags_truesz = 0; > > + struct sk_buff *head_skb; > > + unsigned int frame_sz; > > + struct xdp_buff xdp; > > + void *data; > > + u32 act; > > + int err; > > + > > + data = mergeable_xdp_prepare(vi, rq, xdp_prog, ctx, &frame_sz, > > &num_buf, &page, > > + offset, &len, hdr); > > + if (!data) > > + goto err_xdp; > > + > > + err = virtnet_build_xdp_buff_mrg(dev, vi, rq, &xdp, data, len, frame_sz, > > + &num_buf, &xdp_frags_truesz, stats); > > + if (unlikely(err)) > > + goto err_xdp; > > + > > + act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats); > > + > > + switch (act) { > > + 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; > > + return head_skb; > > + > > + case VIRTNET_XDP_RES_CONSUMED: > > + return NULL; > > + > > + case VIRTNET_XDP_RES_DROP: > > + break; > > + } > > + > > +err_xdp: > > + put_page(page); > > + mergeable_buf_free(rq, num_buf, dev, stats); > > + > > + stats->xdp_drops++; > > + stats->drops++; > > + return NULL; > > +} > > + > > static struct sk_buff *receive_mergeable(struct net_device *dev, > > struct virtnet_info *vi, > > struct receive_queue *rq, > > @@ -1325,21 +1382,22 @@ static struct sk_buff *receive_mergeable(struct > > net_device *dev, > > unsigned int *xdp_xmit, > > struct virtnet_rq_stats *stats) > > { > > - struct virtio_net_hdr_mrg_rxbuf *hdr = buf; > > - int num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers); > > - struct page *page = virt_to_head_page(buf); > > - int offset = buf - page_address(page); > > - struct sk_buff *head_skb, *curr_skb; > > - struct bpf_prog *xdp_prog; > > unsigned int truesize = mergeable_ctx_to_truesize(ctx); > > unsigned int headroom = mergeable_ctx_to_headroom(ctx); > > unsigned int tailroom = headroom ? sizeof(struct skb_shared_info) : 0; > > unsigned int room = SKB_DATA_ALIGN(headroom + tailroom); > > - unsigned int frame_sz; > > - int err; > > + struct virtio_net_hdr_mrg_rxbuf *hdr; > > + struct sk_buff *head_skb, *curr_skb; > > + struct bpf_prog *xdp_prog; > > + struct page *page; > > + int num_buf; > > + int offset; > > > > head_skb = NULL; > > stats->bytes += len - vi->hdr_len; > > + hdr = buf; > > + num_buf = virtio16_to_cpu(vi->vdev, hdr->num_buffers); > > + page = virt_to_head_page(buf); > > > > if (unlikely(len > truesize - room)) { > > pr_debug("%s: rx error: len %u exceeds truesize %lu\n", > > @@ -1348,51 +1406,21 @@ static struct sk_buff *receive_mergeable(struct > > net_device *dev, > > goto err_skb; > > } > > > > - if (likely(!vi->xdp_enabled)) { > > - xdp_prog = NULL; > > - goto skip_xdp; > > - } > > - > > - rcu_read_lock(); > > - xdp_prog = rcu_dereference(rq->xdp_prog); > > - if (xdp_prog) { > > - unsigned int xdp_frags_truesz = 0; > > - struct xdp_buff xdp; > > - void *data; > > - u32 act; > > - > > - data = mergeable_xdp_prepare(vi, rq, xdp_prog, ctx, &frame_sz, > > &num_buf, &page, > > - offset, &len, hdr); > > - if (!data) > > - goto err_xdp; > > - > > - err = virtnet_build_xdp_buff_mrg(dev, vi, rq, &xdp, data, len, > > frame_sz, > > - &num_buf, &xdp_frags_truesz, > > stats); > > - if (unlikely(err)) > > - goto err_xdp; > > - > > - act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats); > > - > > - switch (act) { > > - 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; > > - > > + if (likely(vi->xdp_enabled)) { > > This changes the branch prediction hint compared to the existing code; > as we currently have: > if (likely(!vi->xdp_enabled)) { > > > and I think it would be better avoid such change.
Yes. Will fix. Thanks. > > Thanks, > > Paolo > _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
