From 84214ab4689f962b4bfc47fc9a5838d25ac4274d Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Tue, 18 Apr 2023 15:30:42 +0200 Subject: igc: Enable and fix RX hash usage by netstack When function igc_rx_hash() was introduced in v4.20 via commit 0507ef8a0372 ("igc: Add transmit and receive fastpath and interrupt handlers"), the hardware wasn't configured to provide RSS hash, thus it made sense to not enable net_device NETIF_F_RXHASH feature bit. The NIC hardware was configured to enable RSS hash info in v5.2 via commit 2121c2712f82 ("igc: Add multiple receive queues control supporting"), but forgot to set the NETIF_F_RXHASH feature bit. The original implementation of igc_rx_hash() didn't extract the associated pkt_hash_type, but statically set PKT_HASH_TYPE_L3. The largest portions of this patch are about extracting the RSS Type from the hardware and mapping this to enum pkt_hash_types. This was based on Foxville i225 software user manual rev-1.3.1 and tested on Intel Ethernet Controller I225-LM (rev 03). For UDP it's worth noting that RSS (type) hashing have been disabled both for IPv4 and IPv6 (see IGC_MRQC_RSS_FIELD_IPV4_UDP + IGC_MRQC_RSS_FIELD_IPV6_UDP) because hardware RSS doesn't handle fragmented pkts well when enabled (can cause out-of-order). This results in PKT_HASH_TYPE_L3 for UDP packets, and hash value doesn't include UDP port numbers. Not being PKT_HASH_TYPE_L4, have the effect that netstack will do a software based hash calc calling into flow_dissect, but only when code calls skb_get_hash(), which doesn't necessary happen for local delivery. For QA verification testing I wrote a small bpftrace prog: [0] https://github.com/xdp-project/xdp-project/blob/master/areas/hints/monitor_skb_hash_on_dev.bt Fixes: 2121c2712f82 ("igc: Add multiple receive queues control supporting") Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann Acked-by: Song Yoong Siang Link: https://lore.kernel.org/bpf/168182464270.616355.11391652654430626584.stgit@firesoul --- drivers/net/ethernet/intel/igc/igc_main.c | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) (limited to 'drivers/net/ethernet/intel/igc/igc_main.c') diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index ba49728be919..f6b03e0372e0 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -1687,14 +1687,36 @@ static void igc_rx_checksum(struct igc_ring *ring, le32_to_cpu(rx_desc->wb.upper.status_error)); } +/* Mapping HW RSS Type to enum pkt_hash_types */ +static const enum pkt_hash_types igc_rss_type_table[IGC_RSS_TYPE_MAX_TABLE] = { + [IGC_RSS_TYPE_NO_HASH] = PKT_HASH_TYPE_L2, + [IGC_RSS_TYPE_HASH_TCP_IPV4] = PKT_HASH_TYPE_L4, + [IGC_RSS_TYPE_HASH_IPV4] = PKT_HASH_TYPE_L3, + [IGC_RSS_TYPE_HASH_TCP_IPV6] = PKT_HASH_TYPE_L4, + [IGC_RSS_TYPE_HASH_IPV6_EX] = PKT_HASH_TYPE_L3, + [IGC_RSS_TYPE_HASH_IPV6] = PKT_HASH_TYPE_L3, + [IGC_RSS_TYPE_HASH_TCP_IPV6_EX] = PKT_HASH_TYPE_L4, + [IGC_RSS_TYPE_HASH_UDP_IPV4] = PKT_HASH_TYPE_L4, + [IGC_RSS_TYPE_HASH_UDP_IPV6] = PKT_HASH_TYPE_L4, + [IGC_RSS_TYPE_HASH_UDP_IPV6_EX] = PKT_HASH_TYPE_L4, + [10] = PKT_HASH_TYPE_NONE, /* RSS Type above 9 "Reserved" by HW */ + [11] = PKT_HASH_TYPE_NONE, /* keep array sized for SW bit-mask */ + [12] = PKT_HASH_TYPE_NONE, /* to handle future HW revisons */ + [13] = PKT_HASH_TYPE_NONE, + [14] = PKT_HASH_TYPE_NONE, + [15] = PKT_HASH_TYPE_NONE, +}; + static inline void igc_rx_hash(struct igc_ring *ring, union igc_adv_rx_desc *rx_desc, struct sk_buff *skb) { - if (ring->netdev->features & NETIF_F_RXHASH) - skb_set_hash(skb, - le32_to_cpu(rx_desc->wb.lower.hi_dword.rss), - PKT_HASH_TYPE_L3); + if (ring->netdev->features & NETIF_F_RXHASH) { + u32 rss_hash = le32_to_cpu(rx_desc->wb.lower.hi_dword.rss); + u32 rss_type = igc_rss_type(rx_desc); + + skb_set_hash(skb, rss_hash, igc_rss_type_table[rss_type]); + } } static void igc_rx_vlan(struct igc_ring *rx_ring, @@ -6551,6 +6573,7 @@ static int igc_probe(struct pci_dev *pdev, netdev->features |= NETIF_F_TSO; netdev->features |= NETIF_F_TSO6; netdev->features |= NETIF_F_TSO_ECN; + netdev->features |= NETIF_F_RXHASH; netdev->features |= NETIF_F_RXCSUM; netdev->features |= NETIF_F_HW_CSUM; netdev->features |= NETIF_F_SCTP_CRC; -- cgit