[PATCH net v2 0/2] Fix ntuple rules targeting default RSS

[Gal Pressman <gal@nvidia.com>]

This series addresses a regression in ethtool flow steering where rules
targeting the default RSS context (context 0) were incorrectly rejected.

The default RSS context always exists but is not stored in the rss_ctx
xarray like additional contexts. The current validation logic was
checking for the existence of context 0 in this array, causing valid
flow steering rules to be rejected.

This prevented configurations such as:
- High priority rules directing specific traffic to the default context
- Low priority catch-all rules directing remaining traffic to additional
  contexts

Patch 1 fixes the validation logic to skip the existence check for
context 0.

Patch 2 adds a selftest that verifies this behavior.

Changelog -
v1->v2: https://lore.kernel.org/all/20250225071348.509432-1-gal@nvidia.com/
* Reworded commit message.
* Added a selftest.

Gal Pressman (2):
  net: ethtool: Don't check if RSS context exists in case of context 0
  selftests: drv-net: rss_ctx: Add test for ntuple rules targeting
    default RSS context

 net/ethtool/ioctl.c                           |  3 +-
 .../selftests/drivers/net/hw/rss_ctx.py       | 59 ++++++++++++++++++-
 2 files changed, 60 insertions(+), 2 deletions(-)

-- 
2.40.1