This patchset introduces a new dedicated ethtool_ops callback,
.get_rx_ring_count, which enables drivers to provide the number of RX
rings directly, improving efficiency and clarity in RX ring queries and
RSS configuration.

Number of drivers no implement .get_rxnfc just to report the ring count,
so, having a proper callback makes sense and simplify .get_rxnfc.

This has been suggested by Jakub, and follow the same idea as RXFH
driver callbacks [1].

This also port virtio_net to this new callback. Once there is consensus
on this approach, I can start moving the drivers to this new callback.

Link: https://lore.kernel.org/all/20250611145949.2674086-1-kuba@kernel.org/ [1]

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
---
Changes from RFC:
- Renaming and changing the return type of .get_rxrings() callback (Jakub)
- Add the docstring format for the new callback (Simon)
- Remove the unecessary WARN_ONCE() (Jakub)
- Link to RFC: https://lore.kernel.org/r/20250905-gxrings-v1-0-984fc471f28f@debian.org

---
Breno Leitao (7):
      net: ethtool: pass the num of RX rings directly to ethtool_copy_validate_indir
      net: ethtool: add support for ETHTOOL_GRXRINGS ioctl
      net: ethtool: remove the duplicated handling from ethtool_get_rxrings
      net: ethtool: add get_rx_ring_count callback to optimize RX ring queries
      net: ethtool: update set_rxfh to use get_num_rxrings helper
      net: ethtool: update set_rxfh_indir to use get_num_rxrings helper
      net: virtio_net: add get_rxrings ethtool callback for RX ring queries

 drivers/net/virtio_net.c | 15 ++--------
 include/linux/ethtool.h  |  2 ++
 net/ethtool/ioctl.c      | 72 ++++++++++++++++++++++++++++++++++++++----------
 3 files changed, 62 insertions(+), 27 deletions(-)
---
base-commit: 9f0730b063b436938ebb6371aecb12ec6ed896e9
change-id: 20250905-gxrings-a2ec22ee2aec

Best regards,
--  
Breno Leitao <leitao@debian.org>