On 31/10/2023 16:40, Ahmed Zaki wrote: > > > On 2023-10-31 06:00, Gal Pressman wrote: >> On 29/10/2023 18:59, Ahmed Zaki wrote: >>> >>> >>> On 2023-10-29 06:48, Gal Pressman wrote: >>>> On 29/10/2023 14:42, Ahmed Zaki wrote: >>>>> >>>>> >>>>> On 2023-10-29 06:25, Gal Pressman wrote: >>>>>> On 21/10/2023 3:00, Ahmed Zaki wrote: >>>>>>> >>>>>>> >>>>>>> On 2023-10-20 17:49, Jakub Kicinski wrote: >>>>>>>> On Fri, 20 Oct 2023 17:14:11 -0600 Ahmed Zaki wrote: >>>>>>>>> I replied to that here: >>>>>>>>> >>>>>>>>> https://lore.kernel.org/all/afb4a06f-cfba-47ba-adb3-09bea7cb5f00@xxxxxxxxx/ >>>>>>>>> >>>>>>>>> I am kind of confused now so please bear with me. ethtool either >>>>>>>>> sends >>>>>>>>> "ethtool_rxfh" or "ethtool_rxnfc". AFAIK "ethtool_rxfh" is the >>>>>>>>> interface >>>>>>>>> for "ethtool -X" which is used to set the RSS algorithm. But we >>>>>>>>> kind of >>>>>>>>> agreed to go with "ethtool -U|-N" for symmetric-xor, and that uses >>>>>>>>> "ethtool_rxnfc" (as implemented in this series). >>>>>>>> >>>>>>>> I have no strong preference. Sounds like Alex prefers to keep it >>>>>>>> closer >>>>>>>> to algo, which is "ethtool_rxfh". >>>>>>>> >>>>>>>>> Do you mean use "ethtool_rxfh" instead of "ethtool_rxnfc"? how >>>>>>>>> would >>>>>>>>> that work on the ethtool user interface? >>>>>>>> >>>>>>>> I don't know what you're asking of us. If you find the code to >>>>>>>> confusing >>>>>>>> maybe someone at Intel can help you :| >>>>>>> >>>>>>> The code is straightforward. I am confused by the requirements: >>>>>>> don't >>>>>>> add a new algorithm but use "ethtool_rxfh". >>>>>>> >>>>>>> I'll see if I can get more help, may be I am missing something. >>>>>>> >>>>>> >>>>>> What was the decision here? >>>>>> Is this going to be exposed through ethtool -N or -X? >>>>> >>>>> I am working on a new version that uses "ethtool_rxfh" to set the >>>>> symmetric-xor. The user will set per-device via: >>>>> >>>>> ethtool -X eth0 hfunc toeplitz symmetric-xor >>>>> >>>>> then specify the per-flow type RSS fields as usual: >>>>> >>>>> ethtool -N|-U eth0 rx-flow-hash <flow_type> s|d|f|n >>>>> >>>>> The downside is that all flow-types will have to be either >>>>> symmetric or >>>>> asymmetric. >>>> >>>> Why are we making the interface less flexible than it can be with -N? >>> >>> Alexander Duyck prefers to implement the "symmetric-xor" interface as an >>> algorithm or extension (please refer to previous messages), but ethtool >>> does not provide flowtype/RSS fields setting via "-X". The above was the >>> best solution that we (at Intel) could think of. >> >> OK, it's a weird we're deliberately limiting our interface, given >> there's already hardware that supports controlling symmetric hashing per >> flow type. >> >> I saw you mentioned the way ice hardware implements symmetric-xor >> somewhere, it definitely needs to be added somewhere in our >> documentation to prevent confusion. >> mlx5 hardware also does symmetric hashing with xor, but not exactly as >> you described, we need the algorithm to be clear. > > Sure. I will add more ice-specific doc in: > Documentation/networking/device_drivers/ethernet/intel/ice.rst I was thinking of somewhere more generic, where ethtool users (not necessarily ice users) can refer to. Perhaps Documentation/networking/ethtool-netlink.rst? Or ethtool man page?
