[PATCH net-next RESEND v7 0/3] netdev-genl: Add an xsk attribute to queues

[Joe Damato <jdamato@fastly.com>]

Greetings:

[Note: RESEND because apparently my gmail oauth2 client is breaking
patches I send]

Welcome to v7. Added CONFIG_XDP_SOCKETS to the selftests/driver/net
kernel config in patch 3. Updated the xdp_helper.c to return -1 on
AF_XDP non-existence, and updated queues.py to skip the test if AF_XDP
does not exist (but fail in other failure cases). Tested on kernels with
and without CONFIG_XDP_SOCKETS enabled.

This is an attempt to followup on something Jakub asked me about [1],
adding an xsk attribute to queues and more clearly documenting which
queues are linked to NAPIs...

After the RFC [2], Jakub suggested creating an empty nest for queues
which have a pool, so I've adjusted this version to work that way.

The nest can be extended in the future to express attributes about XSK
as needed. Queues which are not used for AF_XDP do not have the xsk
attribute present.

I've run the included test on:
  - my mlx5 machine (via NETIF=)
  - without setting NETIF

And the test seems to pass in both cases.

Thanks,
Joe

[1]: https://lore.kernel.org/netdev/20250113143109.60afa59a@kernel.org/
[2]: https://lore.kernel.org/netdev/20250129172431.65773-1-jdamato@fastly.com/

v7:
  - Added CONFIG_XDP_SOCKETS to selftests/driver/net/config as suggested
    by Stanislav.
  - Updated xdp_helper.c to return -1 for AF_XDP non-existence, but 1
    for other failures.
  - Updated queues.py to mark test as skipped if AF_XDP does not exist.

v6: https://lore.kernel.org/bpf/20250210193903.16235-1-jdamato@fastly.com/
  - Added ifdefs for CONFIG_XDP_SOCKETS in patch 2 as Stanislav
    suggested.

v5: https://lore.kernel.org/bpf/20250208041248.111118-1-jdamato@fastly.com/
  - Removed unused ret variable from patch 2 as Simon suggested.

v4: https://lore.kernel.org/lkml/20250207030916.32751-1-jdamato@fastly.com/
  - Add patch 1, as suggested by Jakub, which adds an empty nest helper.
  - Use the helper in patch 2, which makes the code cleaner and prevents
    a possible bug.

v3: https://lore.kernel.org/netdev/20250204191108.161046-1-jdamato@fastly.com/
  - Change comment format in patch 2 to avoid kdoc warnings. No other
    changes.

v2: https://lore.kernel.org/all/20250203185828.19334-1-jdamato@fastly.com/
  - Switched from RFC to actual submission now that net-next is open
  - Adjusted patch 1 to include an empty nest as suggested by Jakub
  - Adjusted patch 2 to update the test based on changes to patch 1, and
    to incorporate some Python feedback from Jakub :)

rfc: https://lore.kernel.org/netdev/20250129172431.65773-1-jdamato@fastly.com/


Joe Damato (3):
  netlink: Add nla_put_empty_nest helper
  netdev-genl: Add an XSK attribute to queues
  selftests: drv-net: Test queue xsk attribute

 Documentation/netlink/specs/netdev.yaml       | 13 ++-
 include/net/netlink.h                         | 15 +++
 include/uapi/linux/netdev.h                   |  6 ++
 net/core/netdev-genl.c                        | 12 +++
 tools/include/uapi/linux/netdev.h             |  6 ++
 .../testing/selftests/drivers/net/.gitignore  |  2 +
 tools/testing/selftests/drivers/net/Makefile  |  3 +
 tools/testing/selftests/drivers/net/config    |  1 +
 tools/testing/selftests/drivers/net/queues.py | 42 +++++++-
 .../selftests/drivers/net/xdp_helper.c        | 98 +++++++++++++++++++
 10 files changed, 194 insertions(+), 4 deletions(-)
 create mode 100644 tools/testing/selftests/drivers/net/.gitignore
 create mode 100644 tools/testing/selftests/drivers/net/xdp_helper.c


base-commit: 4079918ae720e842ed7dff65fedeb9980b374995
-- 
2.43.0