From: Liang Chen Date: Wed, 17 Apr 2024 07:18:22 +0000 (+0800) Subject: virtio_net: Support RX hash XDP hint X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=aa37f8916d20cf58437d507fc9599492a342b3cd;p=linux.git virtio_net: Support RX hash XDP hint 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@daynix.com/#r Signed-off-by: Liang Chen Acked-by: Jesper Dangaard Brouer Reviewed-by: Heng Qi Acked-by: Jason Wang Link: https://lore.kernel.org/r/20240417071822.27831-1-liangchen.linux@gmail.com Signed-off-by: Paolo Abeni --- diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 115c3c5414f2a..7176b956460bf 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -4637,6 +4637,48 @@ static void virtnet_set_big_packets(struct virtnet_info *vi, const int mtu) } } +#define VIRTIO_NET_HASH_REPORT_MAX_TABLE 10 +static enum xdp_rss_hash_type +virtnet_xdp_rss_type[VIRTIO_NET_HASH_REPORT_MAX_TABLE] = { + [VIRTIO_NET_HASH_REPORT_NONE] = XDP_RSS_TYPE_NONE, + [VIRTIO_NET_HASH_REPORT_IPv4] = XDP_RSS_TYPE_L3_IPV4, + [VIRTIO_NET_HASH_REPORT_TCPv4] = XDP_RSS_TYPE_L4_IPV4_TCP, + [VIRTIO_NET_HASH_REPORT_UDPv4] = XDP_RSS_TYPE_L4_IPV4_UDP, + [VIRTIO_NET_HASH_REPORT_IPv6] = XDP_RSS_TYPE_L3_IPV6, + [VIRTIO_NET_HASH_REPORT_TCPv6] = XDP_RSS_TYPE_L4_IPV6_TCP, + [VIRTIO_NET_HASH_REPORT_UDPv6] = XDP_RSS_TYPE_L4_IPV6_UDP, + [VIRTIO_NET_HASH_REPORT_IPv6_EX] = XDP_RSS_TYPE_L3_IPV6_EX, + [VIRTIO_NET_HASH_REPORT_TCPv6_EX] = XDP_RSS_TYPE_L4_IPV6_TCP_EX, + [VIRTIO_NET_HASH_REPORT_UDPv6_EX] = XDP_RSS_TYPE_L4_IPV6_UDP_EX +}; + +static int virtnet_xdp_rx_hash(const struct xdp_md *_ctx, u32 *hash, + enum xdp_rss_hash_type *rss_type) +{ + const struct xdp_buff *xdp = (void *)_ctx; + struct virtio_net_hdr_v1_hash *hdr_hash; + struct virtnet_info *vi; + u16 hash_report; + + if (!(xdp->rxq->dev->features & NETIF_F_RXHASH)) + return -ENODATA; + + vi = netdev_priv(xdp->rxq->dev); + hdr_hash = (struct virtio_net_hdr_v1_hash *)(xdp->data - vi->hdr_len); + hash_report = __le16_to_cpu(hdr_hash->hash_report); + + if (hash_report >= VIRTIO_NET_HASH_REPORT_MAX_TABLE) + hash_report = VIRTIO_NET_HASH_REPORT_NONE; + + *rss_type = virtnet_xdp_rss_type[hash_report]; + *hash = __le32_to_cpu(hdr_hash->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; @@ -4765,6 +4807,7 @@ 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)