setting rx-flow-hash for ESP
(too old to reply)
Sowmini Varadhan
2015-10-23 11:16:36 UTC

I have a setup that uses ipsec/esp, and in theory, since the SPI
falls in the same byte location as the tcp ports, one ought to
be able to set up the rx-flow-hash etc based on the spi.

But when I try something like this:

# ethtool -N eth13 rx-flow-hash esp4 sdfn
Cannot change RX network flow hashing options: Invalid argument

I see that is error-ing out (for me) in ixgbe_set_rss_hash_opt() for
nfc->flow_type == 4 (AH_ESP_V4_FLOW). But is there a significant
technical reason why this cannot follow the same logic as
TCP_V4_FLOW or TCP_V6_FLOW, i.e., use "sdfn" for classification
(my reading of the code in that function is that tcp v4/v6 flows
do sdfn by default).

Related question that motivates this, has anyone looked into whether
sdfn would improve perf for esp?