[Intel-wired-lan] [PATCH iwl-next v3 0/2] ice: implement symmetric RSS hash configuration

[Aleksandr Loktionov]

The ice driver has advertised symmetric RSS support via
supported_input_xfrm since the capability was added, but ice_set_rxfh()
ignored the input_xfrm parameter entirely, so enabling symmetric hashing
had no actual effect.

This series fixes that.  Patch 1 extends the ethtool core so that
drivers hashing GTP flows on TEID can report it honestly without
blocking symmetric-xor configuration.  Patch 2 wires up the ice driver.

The need for patch 1 surfaced because GTP flow profiles in ice always
include TEID in the hash.  ethtool_check_flow_types() calls
get_rxfh_fields() for every hashable flow type before allowing
symmetric-xor; ethtool_rxfh_config_is_sym() rejected any bitmap
containing RXH_GTP_TEID since it has no src/dst counterpart.  TEID
is the same value in both tunnel directions, so this rejection is
incorrect: including it does not break symmetry.

Rather than hiding TEID from the reported fields (which would silently
misrepresent hardware behaviour), patch 1 fixes the validator, and
patch 2 reports TEID honestly.

Tested with tools/testing/selftests/drivers/net/hw/rss_input_xfrm.py
on an E810 card running kernel 6.19-rc8.

---
v2 -> v3:
 - Split into 2 patches: ethtool core fix separate from driver change
 - Drop the RXH_GTP_TEID stripping workaround from the driver; instead
   fix ethtool_rxfh_config_is_sym() to accept TEID as intrinsically
   symmetric (patch 1)
 - Fix ice_get_rxfh_fields(): the v2 unconditional assignment
   "nfc->data = ICE_RSS_ALLOWED_FIELDS" clobbered fields set earlier in
   the same function; replaced with pair-completion using |= so only
   the missing half of a partial pair is filled in
 - Remove ICE_RSS_ALLOWED_FIELDS define (no longer needed)
 - Report RXH_GTP_TEID honestly for GTP flow types

v1 -> v2:
 - Preserve valid symmetric RSS fields instead of overwriting nfc->data
   unconditionally

Aleksandr Loktionov (2):
  ethtool: treat RXH_GTP_TEID as intrinsically symmetric
  ice: implement symmetric RSS hash configuration

 drivers/net/ethernet/intel/ice/ice_ethtool.c | 48 +++++++++++++---
 drivers/net/ethernet/intel/ice/ice_lib.c     |  7 ++-
 drivers/net/ethernet/intel/ice/ice_lib.h     |  1 +
 net/ethtool/common.c                         |  3 +
 4 files changed, 47 insertions(+), 12 deletions(-)

-- 
2.43.0