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[iwl-next,v4,0/2] ice: implement symmetric RSS hash configuration

Message ID 20260226144037.400815-1-aleksandr.loktionov@intel.com
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Series ice: implement symmetric RSS hash configuration | expand

Message

Aleksandr Loktionov Feb. 26, 2026, 2:40 p.m. UTC 
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.

---
v3 -> v4:
 - Drop the ICE_HASH_INVALID fallback in ice_get_rxfh_fields() that
   fabricated default L3+L4 hash fields when no hardware RSS config
   exists for a flow type; returning zero fields is more honest and
   avoids misrepresenting hardware state
 - Drop the companion "if (!l3 && !l4)" special case in the
   pair-completion block; it was only necessary to cover the synthetic
   defaults added by the fallback, which is now gone
 - No functional change to ice_set_rxfh() or the ethtool core patch

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 | 40 +++++++++++++---
 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, 40 insertions(+), 11 deletions(-)