BPF CI for Stable

[Shung-Hsi Yu <shung-hsi.yu@suse.com>]

Hi,

Following up on the LSF/MM/BPF 2026 session "BPF in Stable Kernels, an
Update"[1]. Since the event, 6.1 coverage has also been added[2] (thanks
to Paul). With a collaborator on my side, it seem like a good time to
ask:

  Is it possible to get BPF CI for stable in its own repository under a
  GitHub organization (e.g. libbpf/stable-bpf-ci)?

Currently it lives as a personal repo that is fork of libbpf/libbpf[3].
As someone (I think it was Andrii) pointed out during the session, the
vast files currently in my fork are not needed at all. The GitHub Action
workflow only needs the .github/, plus the supplement files under ci/.

Technically BPF CI for stable can also simply be merged back to
libbpf/libbpf, but that felt less ideal because:
- kbuilder-debian container image currently doesn't work when testing
  stable kernels (I haven't look at reason of failure, might not be hard
  to fix)
- actions that tests stable kernel will be mixed with actions targeting
  libbpf itself 
- BPF CI for stable will have to contain version-specific tweaks (e.g.
  [4])

None of the above are fatal flaws that prevent libbf/libbpf to host
files that run BPF selftests on stable kernel, so I'd say having a
standalone repository is more of a personal preference.

OTOH we can also try kernel-patches/bpf-like approach and have a
kernel-patches/stable, providing proper, fully-fledged BPF CI for stable
that tests incoming patchset to stable (not sure if Daniel was asking
about this during the session). But I find this to be much more work.
The current approach of applying queued patches from stable-queue[5],
while comes with quite some delay between the moment patch is proposed
to stable mailing vs the moment said patch gets tested, seem like a
workable compromise.


Thanks,
Shung-Hsi

1: https://speakerdeck.com/shunghsiyu/bpf-in-stable-kernels-an-update
2: https://github.com/shunghsiyu/libbpf/pull/5
3: https://github.com/shunghsiyu/libbpf/
4: https://github.com/shunghsiyu/libbpf/tree/master/ci/diffs/6.1
5: https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/