On Thu, 25 Jan 2024 18:19:12 +0800, Liang Chen <liangchen.linux@xxxxxxxxx> wrote: > The RSS hash report is a feature that's part of the virtio specification. > Currently, virtio backends like qemu, vdpa (mlx5), and potentially vhost > (still a work in progress as per [1]) support this feature. While the > capability to obtain the RSS hash has been enabled in the normal path, > it's currently missing in the XDP path. Therefore, we are introducing > XDP hints through kfuncs to allow XDP programs to access the RSS hash. > > 1. > https://lore.kernel.org/all/20231015141644.260646-1-akihiko.odaki@xxxxxxxxxx/#r > > Signed-off-by: Liang Chen <liangchen.linux@xxxxxxxxx> > --- > drivers/net/virtio_net.c | 98 +++++++++++++++++++++++++++++++++++----- > 1 file changed, 86 insertions(+), 12 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index d7ce4a1011ea..0c845f2223da 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -349,6 +349,12 @@ struct virtio_net_common_hdr { > }; > }; > > +struct virtnet_xdp_buff { > + struct xdp_buff xdp; > + u32 hash_value; > + u16 hash_report; > +}; > + > static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf); > > static bool is_xdp_frame(void *ptr) > @@ -1033,6 +1039,16 @@ static void put_xdp_frags(struct xdp_buff *xdp) > } > } > > +static void virtnet_xdp_save_rx_hash(struct virtnet_xdp_buff *virtnet_xdp, > + struct net_device *dev, > + struct virtio_net_hdr_v1_hash *hdr_hash) > +{ > + if (dev->features & NETIF_F_RXHASH) { > + virtnet_xdp->hash_value = __le32_to_cpu(hdr_hash->hash_value); > + virtnet_xdp->hash_report = __le16_to_cpu(hdr_hash->hash_report); Could we put the __leXX_to_cpu to virtnet_xdp_rx_hash? Other looks good to me. Reviewed-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> Thanks. > + } > +} > + > static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp, > struct net_device *dev, > unsigned int *xdp_xmit, > @@ -1199,9 +1215,10 @@ static struct sk_buff *receive_small_xdp(struct net_device *dev, > unsigned int headroom = vi->hdr_len + header_offset; > struct virtio_net_hdr_mrg_rxbuf *hdr = buf + header_offset; > struct page *page = virt_to_head_page(buf); > + struct virtnet_xdp_buff virtnet_xdp; > struct page *xdp_page; > + struct xdp_buff *xdp; > unsigned int buflen; > - struct xdp_buff xdp; > struct sk_buff *skb; > unsigned int metasize = 0; > u32 act; > @@ -1233,17 +1250,20 @@ static struct sk_buff *receive_small_xdp(struct net_device *dev, > page = xdp_page; > } > > - xdp_init_buff(&xdp, buflen, &rq->xdp_rxq); > - xdp_prepare_buff(&xdp, buf + VIRTNET_RX_PAD + vi->hdr_len, > + xdp = &virtnet_xdp.xdp; > + xdp_init_buff(xdp, buflen, &rq->xdp_rxq); > + xdp_prepare_buff(xdp, buf + VIRTNET_RX_PAD + vi->hdr_len, > xdp_headroom, len, true); > > - act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats); > + virtnet_xdp_save_rx_hash(&virtnet_xdp, dev, (void *)hdr); > + > + act = virtnet_xdp_handler(xdp_prog, xdp, dev, xdp_xmit, stats); > > switch (act) { > case XDP_PASS: > /* Recalculate length in case bpf program changed it */ > - len = xdp.data_end - xdp.data; > - metasize = xdp.data - xdp.data_meta; > + len = xdp->data_end - xdp->data; > + metasize = xdp->data - xdp->data_meta; > break; > > case XDP_TX: > @@ -1254,7 +1274,7 @@ static struct sk_buff *receive_small_xdp(struct net_device *dev, > goto err_xdp; > } > > - skb = virtnet_build_skb(buf, buflen, xdp.data - buf, len); > + skb = virtnet_build_skb(buf, buflen, xdp->data - buf, len); > if (unlikely(!skb)) > goto err; > > @@ -1591,10 +1611,11 @@ static struct sk_buff *receive_mergeable_xdp(struct net_device *dev, > 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 virtnet_xdp_buff virtnet_xdp; > unsigned int xdp_frags_truesz = 0; > struct sk_buff *head_skb; > unsigned int frame_sz; > - struct xdp_buff xdp; > + struct xdp_buff *xdp; > void *data; > u32 act; > int err; > @@ -1604,16 +1625,19 @@ static struct sk_buff *receive_mergeable_xdp(struct net_device *dev, > if (unlikely(!data)) > goto err_xdp; > > - err = virtnet_build_xdp_buff_mrg(dev, vi, rq, &xdp, data, len, frame_sz, > + xdp = &virtnet_xdp.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); > + virtnet_xdp_save_rx_hash(&virtnet_xdp, dev, (void *)hdr); > + > + act = virtnet_xdp_handler(xdp_prog, xdp, dev, xdp_xmit, stats); > > switch (act) { > case XDP_PASS: > - head_skb = build_skb_from_xdp_buff(dev, vi, &xdp, xdp_frags_truesz); > + head_skb = build_skb_from_xdp_buff(dev, vi, xdp, xdp_frags_truesz); > if (unlikely(!head_skb)) > break; > return head_skb; > @@ -1626,7 +1650,7 @@ static struct sk_buff *receive_mergeable_xdp(struct net_device *dev, > break; > } > > - put_xdp_frags(&xdp); > + put_xdp_frags(xdp); > > err_xdp: > put_page(page); > @@ -4579,6 +4603,55 @@ static void virtnet_set_big_packets(struct virtnet_info *vi, const int mtu) > } > } > > +static int virtnet_xdp_rx_hash(const struct xdp_md *_ctx, u32 *hash, > + enum xdp_rss_hash_type *rss_type) > +{ > + const struct virtnet_xdp_buff *virtnet_xdp = (void *)_ctx; > + > + if (!(virtnet_xdp->xdp.rxq->dev->features & NETIF_F_RXHASH)) > + return -ENODATA; > + > + switch (virtnet_xdp->hash_report) { > + case VIRTIO_NET_HASH_REPORT_TCPv4: > + *rss_type = XDP_RSS_TYPE_L4_IPV4_TCP; > + break; > + case VIRTIO_NET_HASH_REPORT_UDPv4: > + *rss_type = XDP_RSS_TYPE_L4_IPV4_UDP; > + break; > + case VIRTIO_NET_HASH_REPORT_TCPv6: > + *rss_type = XDP_RSS_TYPE_L4_IPV6_TCP; > + break; > + case VIRTIO_NET_HASH_REPORT_UDPv6: > + *rss_type = XDP_RSS_TYPE_L4_IPV6_UDP; > + break; > + case VIRTIO_NET_HASH_REPORT_TCPv6_EX: > + *rss_type = XDP_RSS_TYPE_L4_IPV6_TCP_EX; > + break; > + case VIRTIO_NET_HASH_REPORT_UDPv6_EX: > + *rss_type = XDP_RSS_TYPE_L4_IPV6_UDP_EX; > + break; > + case VIRTIO_NET_HASH_REPORT_IPv4: > + *rss_type = XDP_RSS_TYPE_L3_IPV4; > + break; > + case VIRTIO_NET_HASH_REPORT_IPv6: > + *rss_type = XDP_RSS_TYPE_L3_IPV6; > + break; > + case VIRTIO_NET_HASH_REPORT_IPv6_EX: > + *rss_type = XDP_RSS_TYPE_L3_IPV6_EX; > + break; > + case VIRTIO_NET_HASH_REPORT_NONE: > + default: > + *rss_type = XDP_RSS_TYPE_NONE; > + } > + > + *hash = virtnet_xdp->hash_value; > + return 0; > +} > + > +static const struct xdp_metadata_ops virtnet_xdp_metadata_ops = { > + .xmo_rx_hash = virtnet_xdp_rx_hash, > +}; > + > static int virtnet_probe(struct virtio_device *vdev) > { > int i, err = -ENOMEM; > @@ -4704,6 +4777,7 @@ static int virtnet_probe(struct virtio_device *vdev) > VIRTIO_NET_RSS_HASH_TYPE_UDP_EX); > > dev->hw_features |= NETIF_F_RXHASH; > + dev->xdp_metadata_ops = &virtnet_xdp_metadata_ops; > } > > if (vi->has_rss_hash_report) > -- > 2.40.1 >
