On Wed, 13 Nov 2024 17:32:17 +0000 Taehee Yoo wrote: > NICs that uses bnxt_en driver supports tcp-data-split feature by the > name of HDS(header-data-split). > But there is no implementation for the HDS to enable by ethtool. > Only getting the current HDS status is implemented and The HDS is just > automatically enabled only when either LRO, HW-GRO, or JUMBO is enabled. > The hds_threshold follows rx-copybreak value. and it was unchangeable. > > This implements `ethtool -G <interface name> tcp-data-split <value>` > command option. > The value can be <on> and <auto>. > The value is <auto> and one of LRO/GRO/JUMBO is enabled, HDS is > automatically enabled and all LRO/GRO/JUMBO are disabled, HDS is > automatically disabled. > > HDS feature relies on the aggregation ring. > So, if HDS is enabled, the bnxt_en driver initializes the aggregation ring. > This is the reason why BNXT_FLAG_AGG_RINGS contains HDS condition. I may be missing some existing check but doesn't enabling XDP force page_mode which in turn clears BNXT_FLAG_AGG_RINGS, including HDS ? If user specifically requested HDS we should refuse to install XDP in non-multibuf mode. TBH a selftest under tools/testing/drivers/net would go a long way to make it clear we caught all cases. You can add a dummy netdevsim implementation for testing without bnxt present (some of the existing python tests can work with real drivers and netdevsim): https://github.com/linux-netdev/nipa/wiki/Running-driver-tests
