Re: [PATCH net 2/7] selftests: openvswitch: add config file

[Matthieu Baerts <matttbe@kernel.org>]

On 20/07/2026 16:43, Aaron Conole wrote:
> Matthieu Baerts <matttbe@kernel.org> writes:
> 
>> Hi Aaron,
>>
>> Thank you for the review!
>>
>> On 16/07/2026 22:00, Aaron Conole wrote:
>>> Aaron Conole <aconole@redhat.com> writes:
>>>> "Matthieu Baerts (NGI0)" <matttbe@kernel.org> writes:
>>>>
>>>>> The kselftests doc mentions that a config file should be present "if a
>>>>> test needs specific kernel config options enabled". This selftest
>>>>> requires some kernel config, but no config file was provided.
>>>>>
>>>>> We could say that a sub-target could use the parent's config file, but
>>>>> the kselftests doc doesn't mention anything about that. Plus the
>>>>> net/openvswitch target is the only net target without a config file.
>>>>
>>>> We've been operating on that assumption from the openvswitch side, but
>>>> it's true that isn't explicitly documented anywhere, and I guess it
>>>> isn't officially supported in the kselftest framework.  I guess we'll
>>>> need to keep updating this config as we add tests for things like SCTP,
>>>> and others, and maybe that's a good thing like we can add a comment
>>>> describing which tests take which configs.
>>>>
>>>> The downside is for most of the OVS testing we use the NIPA scripts
>>>> and those 'inherit' the parent config, so it would be a change on our
>>>> side from the development standpoint (but probably something we should
>>>> have been doing from the beginning).
>>>>
>>>> That said, would it be worth also exploring the 'cascading
>>>> configuration' support?  It seems like a useful feature, but maybe it
>>>> should be a separate discussion.  I ask because of how OVS interacts
>>>> with the networking stack as an 'alternative bridge' so-to-speak, I do
>>>> worry about having to duplicate lots of configurations between the two
>>>> as we expand the test coverage on OVS side.
>>
>> It is not clear to me what you are using on your side, but I guess it
>> should be doable to modify some scripts to merge this new config file
>> and the net one in your case.
> 
> This doesn't seem to break the NIPA case (at least I can see the
> 'contest test' output is not SKIP, but PASS for the openvswitch.sh).

Note that currently, the net/openvswitch target on NIPA is executed on
the same runner as the net one. In other words, the config files are
merged, so at the end, my patch shouldn't change anything with the way
NIPA is currently deployed (but that could change).

> I'm not sure about the suggestion to change the script in
> tools/testing/selftests/net/openvswitch/openvswitch.sh to do a config
> merge.  It isn't out-of-tree or anything, and seems like that would
> create confusing git state (and not desirable from my end) - the
> upstream test would leave a modified, tracked file.  Was that your
> suggestion?  Or do you mean NIPA itself (but I think it already just
> uses the top-level config).

No, sorry, I thought my modification would have caused issues with other
tests on your side. Good to hear it is not.

> The config change itself looks fine to me.

Thank you!

>>>>> Here is a new config file, which is a trimmed version of the net one,
>>>>> with hopefully the minimal required kconfig on top of 'make defconfig'.
>>>>
>>>> Should this also remove the OVS configs from the upper level since there
>>>> shouldn't be OVS tests executing there (ie: CONFIG_OPENVSWITCH*)?
>>>
>>> Actually, forget this part.  The P-MTU tests in pmtu.sh use ovs to
>>> create a datapath through OVS.  So these configurations need to stay at
>>> the top level as well.
>>
>> Indeed. I don't know these tests well, but maybe this P-MTU selftest
>> should move to the net/openvswitch target?
> 
> Well, it is testing path MTU across multiple topologies, so it isn't
> really an openvswitch specific test.  Just one that happens to use
> openvswitch in one of the test cases.

OK, it is fine there then.

Note that the openvswitch test could also be moved to the 'net' one. It
looks like the sub-targets are often created when there are multiple
tests linked to one sub-subsystem, and also because the 'net' config is
quite big, and it takes time to compile all that. But I'm not pushing
for one or the other, I just wanted to be able to build all targets in
small containers :)

Cheers,
Matt