Merge branch 'mlx4-add-support-for-netdev-genl-api'

Merge branch 'mlx4-add-support-for-netdev-genl-api'

Joe Damato says:

====================
mlx4: Add support for netdev-genl API

There are no functional changes from v5, which I mistakenly sent right
after net-next was closed (oops). This revision, however, includes
Tariq's Reviewed-by tags of the v5 in each commit message. See the
changelog below.

This series adds support to mlx4 for the netdev-genl API which makes it
much easier for users and user programs to map NAPI IDs back to
ifindexes, queues, and IRQs. This is extremely useful for a number of
use cases, including epoll-based busy poll.

In addition, this series includes a patch to generate per-queue
statistics using the netlink API, as well.

To facilitate the stats, patch 1/3 adds a field "alloc_fail" to the ring
structure. This is incremented by the driver in an appropriate place and
used in patch 3/3 as alloc_fail.

Please note: I do not have access to mlx4 hardware, but I've been
working closely with Martin Karsten from University of Waterloo (CC'd)
who has very graciously tested my patches on their mlx4 hardware (hence
his Tested-by attribution in each commit). His latest research work is
particularly interesting [1] and this series helps to support that (and
future) work.

Martin re-test v4 using Jakub's suggested tool [2] and the
stats.pkt_byte_sum and stats.qstat_by_ifindex tests passed. He also
adjusted the queue count and re-ran test to confirm it still passed even
if the queue count was modified.

[1]: https://dl.acm.org/doi/pdf/10.1145/3626780
[2]: https://lore.kernel.org/lkml/20240423175718.4ad4dc5a@kernel.org/
====================

Link: https://lore.kernel.org/r/20240528181139.515070-1-jdamato@fastly.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>