On 17/02/2023 21.59, Daniel Borkmann wrote:
On 2/16/23 5:52 PM, Jesper Dangaard Brouer wrote: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. Fixes: 2121c2712f82 ("igc: Add multiple receive queues control supporting") Signed-off-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>I presume this should go via net-next, not bpf-next? (Didn't find specific dependencies, so moved to patchwork netdev bucket..)
Thanks for letting me/us know. I posted against bpf-next, because I have patches (for kfunc XDP-hints) that depend on this patch. As we are at rc8, netdev maintainers feel free to simply drop the patch as the patch isn't critical. I will just include this patch as part of my kfunc XDP-hints series later. --Jesper
