Re: [RFC PATCH 3/3] drivers/net/virtio_net: Added RSS hash report.

From: Jason Wang
Date: Wed Sep 01 2021 - 03:40:42 EST


On Thu, Aug 19, 2021 at 1:55 AM Andrew Melnychenko <andrew@xxxxxxxxxx> wrote:
>
> Added set_hash for skb.
> Also added hashflow set/get callbacks.
> Virtio RSS "IPv6 extensions" hashes disabled.
> Also, disabling RXH_IP_SRC/DST for TCP would disable them for UDP.
> TCP and UDP supports only:
> ethtool -U eth0 rx-flow-hash tcp4 sd
> RXH_IP_SRC + RXH_IP_DST
> ethtool -U eth0 rx-flow-hash tcp4 sdfn
> RXH_IP_SRC + RXH_IP_DST + RXH_L4_B_0_1 + RXH_L4_B_2_3
>
> Signed-off-by: Andrew Melnychenko <andrew@xxxxxxxxxx>
> ---
> drivers/net/virtio_net.c | 177 +++++++++++++++++++++++++++++++++++++++
> 1 file changed, 177 insertions(+)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index d87bde246305..6a52eeaf9292 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -1151,6 +1151,8 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
> struct net_device *dev = vi->dev;
> struct sk_buff *skb;
> struct virtio_net_hdr_mrg_rxbuf *hdr;
> + struct virtio_net_hdr_v1_hash *hdr_hash;
> + enum pkt_hash_types rss_hash_type;
>
> if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
> pr_debug("%s: short packet %i\n", dev->name, len);
> @@ -1177,6 +1179,29 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
> return;
>
> hdr = skb_vnet_hdr(skb);
> + if (vi->has_rss_hash_report && (dev->features & NETIF_F_RXHASH)) {
> + hdr_hash = (struct virtio_net_hdr_v1_hash *)(hdr);
> +
> + switch (hdr_hash->hash_report) {
> + case VIRTIO_NET_HASH_REPORT_TCPv4:
> + case VIRTIO_NET_HASH_REPORT_UDPv4:
> + case VIRTIO_NET_HASH_REPORT_TCPv6:
> + case VIRTIO_NET_HASH_REPORT_UDPv6:
> + case VIRTIO_NET_HASH_REPORT_TCPv6_EX:
> + case VIRTIO_NET_HASH_REPORT_UDPv6_EX:
> + rss_hash_type = PKT_HASH_TYPE_L4;
> + break;
> + case VIRTIO_NET_HASH_REPORT_IPv4:
> + case VIRTIO_NET_HASH_REPORT_IPv6:
> + case VIRTIO_NET_HASH_REPORT_IPv6_EX:
> + rss_hash_type = PKT_HASH_TYPE_L3;
> + break;
> + case VIRTIO_NET_HASH_REPORT_NONE:
> + default:
> + rss_hash_type = PKT_HASH_TYPE_NONE;
> + }
> + skb_set_hash(skb, hdr_hash->hash_value, rss_hash_type);
> + }
>
> if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
> skb->ip_summed = CHECKSUM_UNNECESSARY;
> @@ -2250,6 +2275,132 @@ static void virtnet_init_default_rss(struct virtnet_info *vi)
> netdev_rss_key_fill(vi->ctrl->rss.key, vi->rss_key_size);
> }
>
> +void virtnet_get_hashflow(const struct virtnet_info *vi, struct ethtool_rxnfc *info)
> +{
> + info->data = 0;
> + switch (info->flow_type) {
> + case TCP_V4_FLOW:
> + if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_TCPv4) {
> + info->data = RXH_IP_SRC | RXH_IP_DST |
> + RXH_L4_B_0_1 | RXH_L4_B_2_3;
> + } else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv4) {
> + info->data = RXH_IP_SRC | RXH_IP_DST;
> + }
> + break;
> + case TCP_V6_FLOW:
> + if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_TCPv6) {
> + info->data = RXH_IP_SRC | RXH_IP_DST |
> + RXH_L4_B_0_1 | RXH_L4_B_2_3;
> + } else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv6) {
> + info->data = RXH_IP_SRC | RXH_IP_DST;
> + }
> + break;
> + case UDP_V4_FLOW:
> + if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_UDPv4) {
> + info->data = RXH_IP_SRC | RXH_IP_DST |
> + RXH_L4_B_0_1 | RXH_L4_B_2_3;
> + } else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv4) {
> + info->data = RXH_IP_SRC | RXH_IP_DST;
> + }
> + break;
> + case UDP_V6_FLOW:
> + if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_UDPv6) {
> + info->data = RXH_IP_SRC | RXH_IP_DST |
> + RXH_L4_B_0_1 | RXH_L4_B_2_3;
> + } else if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv6) {
> + info->data = RXH_IP_SRC | RXH_IP_DST;
> + }
> + break;
> + case IPV4_FLOW:
> + if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv4)
> + info->data = RXH_IP_SRC | RXH_IP_DST;
> +
> + break;
> + case IPV6_FLOW:
> + if (vi->rss_hash_types_saved & VIRTIO_NET_RSS_HASH_TYPE_IPv4)
> + info->data = RXH_IP_SRC | RXH_IP_DST;
> +
> + break;
> + default:
> + info->data = 0;
> + break;
> + }
> +}
> +
> +bool virtnet_set_hashflow(struct virtnet_info *vi, struct ethtool_rxnfc *info)
> +{
> + u64 is_iphash = info->data & (RXH_IP_SRC | RXH_IP_DST);
> + u64 is_porthash = info->data & (RXH_L4_B_0_1 | RXH_L4_B_2_3);
> + u32 new_hashtypes = vi->rss_hash_types_saved;
> +
> + if ((is_iphash && (is_iphash != (RXH_IP_SRC | RXH_IP_DST))) ||
> + (is_porthash && (is_porthash != (RXH_L4_B_0_1 | RXH_L4_B_2_3)))) {
> + return false;
> + }
> +
> + if (!is_iphash && is_porthash)
> + return false;
> +
> + switch (info->flow_type) {
> + case TCP_V4_FLOW:
> + case UDP_V4_FLOW:
> + case IPV4_FLOW:
> + new_hashtypes &= ~VIRTIO_NET_RSS_HASH_TYPE_IPv4;
> + if (is_iphash)
> + new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv4;
> +
> + break;
> + case TCP_V6_FLOW:
> + case UDP_V6_FLOW:
> + case IPV6_FLOW:
> + new_hashtypes &= ~VIRTIO_NET_RSS_HASH_TYPE_IPv6;
> + if (is_iphash)
> + new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_IPv6;
> +
> + break;
> + default:
> + break;
> + }
> +
> + switch (info->flow_type) {
> + case TCP_V4_FLOW:
> + new_hashtypes &= ~VIRTIO_NET_RSS_HASH_TYPE_TCPv4;
> + if (is_porthash)
> + new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_TCPv4;
> +
> + break;
> + case UDP_V4_FLOW:
> + new_hashtypes &= ~VIRTIO_NET_RSS_HASH_TYPE_UDPv4;
> + if (is_porthash)
> + new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_UDPv4;
> +
> + break;
> + case TCP_V6_FLOW:
> + new_hashtypes &= ~VIRTIO_NET_RSS_HASH_TYPE_TCPv6;
> + if (is_porthash)
> + new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_TCPv6;
> +
> + break;
> + case UDP_V6_FLOW:
> + new_hashtypes &= ~VIRTIO_NET_RSS_HASH_TYPE_UDPv6;
> + if (is_porthash)
> + new_hashtypes |= VIRTIO_NET_RSS_HASH_TYPE_UDPv6;
> +
> + break;
> + default:
> + break;
> + }
> +
> + if (new_hashtypes != vi->rss_hash_types_saved) {
> + vi->rss_hash_types_saved = new_hashtypes;
> + vi->ctrl->rss.table_info.hash_types = vi->rss_hash_types_saved;
> + if (vi->dev->features & NETIF_F_RXHASH)
> + return virtnet_commit_rss_command(vi);
> + }
> +
> + return true;
> +}
> +
> static void virtnet_get_drvinfo(struct net_device *dev,
> struct ethtool_drvinfo *info)
> {
> @@ -2530,8 +2681,28 @@ int virtnet_get_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info, u32 *r
> switch (info->cmd) {
> case ETHTOOL_GRXRINGS:
> info->data = vi->curr_queue_pairs;
> + break;
> + case ETHTOOL_GRXFH:
> + virtnet_get_hashflow(vi, info);
> + break;
> + default:
> rc = -EOPNOTSUPP;
> }
> +
> + return rc;
> +}
> +
> +static int virtnet_set_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info)
> +{
> + struct virtnet_info *vi = netdev_priv(dev);
> + int rc = 0;
> +
> + switch (info->cmd) {
> + case ETHTOOL_SRXFH:
> + if (!virtnet_set_hashflow(vi, info))
> + rc = -EINVAL;
> +
> + break;
> default:
> rc = -EOPNOTSUPP;
> }
> @@ -2559,6 +2730,7 @@ static const struct ethtool_ops virtnet_ethtool_ops = {
> .get_rxfh = virtnet_get_rxfh,
> .set_rxfh = virtnet_set_rxfh,
> .get_rxnfc = virtnet_get_rxnfc,
> + .set_rxnfc = virtnet_set_rxnfc,
> };
>
> static void virtnet_freeze_down(struct virtio_device *vdev)
> @@ -3351,8 +3523,13 @@ static int virtnet_probe(struct virtio_device *vdev)
> if (vi->has_rss || vi->has_rss_hash_report) {
> vi->rss_hash_types_supported =
> virtio_cread32(vdev, offsetof(struct virtio_net_config, supported_hash_types));
> + vi->rss_hash_types_supported &=
> + ~(VIRTIO_NET_RSS_HASH_TYPE_IP_EX |
> + VIRTIO_NET_RSS_HASH_TYPE_TCP_EX |
> + VIRTIO_NET_RSS_HASH_TYPE_UDP_EX);
>
> dev->hw_features |= NETIF_F_RXHASH;
> + dev->features |= NETIF_F_NTUPLE;

I think we don't support ntuple filters but hash filters?

Thanks

> }
>
> if (vi->has_cvq && vi->has_rss_hash_report)
> --
> 2.31.1
>