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network-programmingdpdknicmellanox

Unable to set RSS algorithm in DPDK

I'm trying to configure RSS (Receive Side Scaling) on my Mellanox ConnectX-6 NIC using RTE_ETH_HASH_FUNCTION_TOEPLITZ in DPDK. However, no matter which algorithm I set (except the default), I get the following error:

Ethdev-port_id=0 configured RSS hash algorithm is not in the algorithm capability

From what I understand, this suggests that the NIC does not support the algorithm. However, since Toeplitz is widely used for RSS, I would expect it to be supported.

  1. Can I force-enable RTE_ETH_HASH_FUNCTION_TOEPLITZ via firmware or DPDK settings?
  2. If not supported, is there an alternative approach to achieve the same RSS behavior?

Thanks!

Solution

  • The concept of reporting RSS algorithm support was introduced to DPDK not so long ago (in v23.11) and, therefore, some drivers may not fill in the corresponding field in the device info structure yet. I guess, that is the case for the driver in question, too. That does not necessarily mean the driver does not support Toeplitz. Most certainly, it does support this algorithm, but under the guise of RTE_ETH_HASH_FUNCTION_DEFAULT.

    For now, consider to pass RTE_ETH_HASH_FUNCTION_DEFAULT. My guess is that one will be able to pass RTE_ETH_HASH_FUNCTION_TOEPLITZ choice when the driver maintainers have caught up with the concept and sent the necessary patches.