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author | Jesper Dangaard Brouer <brouer@redhat.com> | 2023-04-18 15:30:42 +0200 |
---|---|---|
committer | Daniel Borkmann <daniel@iogearbox.net> | 2023-04-27 18:42:19 +0200 |
commit | 84214ab4689f962b4bfc47fc9a5838d25ac4274d (patch) | |
tree | c74144d25d99c3a24e48c891e86b910ce5b37011 /drivers/net/ethernet/intel/igc/igc.h | |
parent | bpftool: Show map IDs along with struct_ops links. (diff) | |
download | wireguard-linux-84214ab4689f962b4bfc47fc9a5838d25ac4274d.tar.xz wireguard-linux-84214ab4689f962b4bfc47fc9a5838d25ac4274d.zip |
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 <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Yoong Siang <yoong.siang.song@intel.com>
Link: https://lore.kernel.org/bpf/168182464270.616355.11391652654430626584.stgit@firesoul
Diffstat (limited to 'drivers/net/ethernet/intel/igc/igc.h')
-rw-r--r-- | drivers/net/ethernet/intel/igc/igc.h | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h index 34aebf00a512..f7f9e217e7b4 100644 --- a/drivers/net/ethernet/intel/igc/igc.h +++ b/drivers/net/ethernet/intel/igc/igc.h @@ -13,6 +13,7 @@ #include <linux/ptp_clock_kernel.h> #include <linux/timecounter.h> #include <linux/net_tstamp.h> +#include <linux/bitfield.h> #include "igc_hw.h" @@ -311,6 +312,33 @@ extern char igc_driver_name[]; #define IGC_MRQC_RSS_FIELD_IPV4_UDP 0x00400000 #define IGC_MRQC_RSS_FIELD_IPV6_UDP 0x00800000 +/* RX-desc Write-Back format RSS Type's */ +enum igc_rss_type_num { + IGC_RSS_TYPE_NO_HASH = 0, + IGC_RSS_TYPE_HASH_TCP_IPV4 = 1, + IGC_RSS_TYPE_HASH_IPV4 = 2, + IGC_RSS_TYPE_HASH_TCP_IPV6 = 3, + IGC_RSS_TYPE_HASH_IPV6_EX = 4, + IGC_RSS_TYPE_HASH_IPV6 = 5, + IGC_RSS_TYPE_HASH_TCP_IPV6_EX = 6, + IGC_RSS_TYPE_HASH_UDP_IPV4 = 7, + IGC_RSS_TYPE_HASH_UDP_IPV6 = 8, + IGC_RSS_TYPE_HASH_UDP_IPV6_EX = 9, + IGC_RSS_TYPE_MAX = 10, +}; +#define IGC_RSS_TYPE_MAX_TABLE 16 +#define IGC_RSS_TYPE_MASK GENMASK(3,0) /* 4-bits (3:0) = mask 0x0F */ + +/* igc_rss_type - Rx descriptor RSS type field */ +static inline u32 igc_rss_type(const union igc_adv_rx_desc *rx_desc) +{ + /* RSS Type 4-bits (3:0) number: 0-9 (above 9 is reserved) + * Accessing the same bits via u16 (wb.lower.lo_dword.hs_rss.pkt_info) + * is slightly slower than via u32 (wb.lower.lo_dword.data) + */ + return le32_get_bits(rx_desc->wb.lower.lo_dword.data, IGC_RSS_TYPE_MASK); +} + /* Interrupt defines */ #define IGC_START_ITR 648 /* ~6000 ints/sec */ #define IGC_4K_ITR 980 |