Re: [PATCH bpf-next v3 0/6] XDP metadata support for tun driver

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

Marcus Wichelmann wrote:
> Hi,
> 
> thank you for your reviw. As promised, here is V3 of this patch series.
> 
> I noticed that the updated selftests were flaky sometimes due to the kernel
> networking stack sending IPv6 multicast listener reports on the created
> test interfaces.
> This can be seen here:
> https://github.com/kernel-patches/bpf/actions/runs/13449071153/job/37580497963
> 
> Setting the NOARP flag on the interfaces should fix this race condition.
> 
> Successful pipeline:
> https://github.com/kernel-patches/bpf/actions/runs/13500667544
> 
> Signed-off-by: Marcus Wichelmann <marcus.wichelmann@hetzner-cloud.de>
> Acked-by: Jason Wang <jasowang@redhat.com>
> Reviewed-by: Willem de Bruijn <willemb@google.com>

Please don't add tags, unless a person has explicitly added them.

And they are only sticky when the code has not been changed since
they added them.

These are only in the cover letter, so not picked up. But for future
revisions and patches.

I'll take a closer look at the actual patches in a bit.
 
> ---
> 
> v3:
> - change the condition to handle xdp_buffs without metadata support, as
>   suggested by Willem de Bruijn <willemb@google.com>
> - add clarifying comment why that condition is needed
> - set NOARP flag in selftests to ensure that the kernel does not send
>   packets on the test interfaces that may interfere with the tests
> 
> v2: https://lore.kernel.org/bpf/20250217172308.3291739-1-marcus.wichelmann@hetzner-cloud.de/
> - submit against bpf-next subtree
> - split commits and improved commit messages
> - remove redundant metasize check and add clarifying comment instead
> - use max() instead of ternary operator
> - add selftest for metadata support in the tun driver
> 
> v1: https://lore.kernel.org/all/20250130171614.1657224-1-marcus.wichelmann@hetzner-cloud.de/
> 
> Marcus Wichelmann (6):
>   net: tun: enable XDP metadata support
>   net: tun: enable transfer of XDP metadata to skb
>   selftests/bpf: move open_tuntap to network helpers
>   selftests/bpf: refactor xdp_context_functional test and bpf program
>   selftests/bpf: add test for XDP metadata support in tun driver
>   selftests/bpf: fix file descriptor assertion in open_tuntap helper
> 
>  drivers/net/tun.c                             |  28 ++-
>  tools/testing/selftests/bpf/network_helpers.c |  28 +++
>  tools/testing/selftests/bpf/network_helpers.h |   3 +
>  .../selftests/bpf/prog_tests/lwt_helpers.h    |  29 ----
>  .../bpf/prog_tests/xdp_context_test_run.c     | 163 ++++++++++++++++--
>  .../selftests/bpf/progs/test_xdp_meta.c       |  56 +++---
>  6 files changed, 230 insertions(+), 77 deletions(-)
> 
> -- 
> 2.43.0
>