Re: [PATCH v2 net-next 0/7] selftests: net: Switch pmtu.sh to use the internal ovs script.

[Paolo Abeni <pabeni@redhat.com>]

On Mon, 2024-06-24 at 12:53 -0400, Aaron Conole wrote:
> Aaron Conole <aconole@redhat.com> writes:
> 
> > Jakub Kicinski <kuba@kernel.org> writes:
> > 
> > > On Thu, 20 Jun 2024 08:55:54 -0400 Aaron Conole wrote:
> > > > This series enhances the ovs-dpctl utility to provide support for set()
> > > > and tunnel() flow specifiers, better ipv6 handling support, and the
> > > > ability to add tunnel vports, and LWT interfaces.  Finally, it modifies
> > > > the pmtu.sh script to call the ovs-dpctl.py utility rather than the
> > > > typical OVS userspace utilities.
> > > 
> > > Thanks for the work! 
> > > 
> > > Looks like the series no longer applies because of other changes
> > > to the kernel config. Before it stopped applying we got some runs,
> > > here's what I see:
> > > 
> > > https://netdev-3.bots.linux.dev/vmksft-net/results/648440/3-pmtu-sh/stdout
> > > 
> > > # Cannot find device "ovs_br0"
> > > # TEST: IPv4, OVS vxlan4: PMTU exceptions                             [FAIL]
> > > # Cannot find device "ovs_br0"
> > > # TEST: IPv4, OVS vxlan4: PMTU exceptions - nexthop objects           [FAIL]
> > > # Cannot find device "ovs_br0"
> > > # TEST: IPv6, OVS vxlan4: PMTU exceptions                             [FAIL]
> > > # Cannot find device "ovs_br0"
> > > # TEST: IPv6, OVS vxlan4: PMTU exceptions - nexthop objects           [FAIL]
> > > # Cannot find device "ovs_br0"
> > > # TEST: IPv4, OVS vxlan6: PMTU exceptions                             [FAIL]
> > > # Cannot find device "ovs_br0"
> > > # TEST: IPv4, OVS vxlan6: PMTU exceptions - nexthop objects           [FAIL]
> > > # Cannot find device "ovs_br0"
> > > # TEST: IPv6, OVS vxlan6: PMTU exceptions                             [FAIL]
> > > # Cannot find device "ovs_br0"
> > > # TEST: IPv6, OVS vxlan6: PMTU exceptions - nexthop objects           [FAIL]
> > > # Cannot find device "ovs_br0"
> > > # TEST: IPv4, OVS geneve4: PMTU exceptions                            [FAIL]
> > > # Cannot find device "ovs_br0"
> > > # TEST: IPv4, OVS geneve4: PMTU exceptions - nexthop objects          [FAIL]
> > > # Cannot find device "ovs_br0"
> > > # TEST: IPv6, OVS geneve4: PMTU exceptions                            [FAIL]
> > > # Cannot find device "ovs_br0"
> > > # TEST: IPv6, OVS geneve4: PMTU exceptions - nexthop objects          [FAIL]
> > > # Cannot find device "ovs_br0"
> > > # TEST: IPv4, OVS geneve6: PMTU exceptions                            [FAIL]
> > > # Cannot find device "ovs_br0"
> > > # TEST: IPv4, OVS geneve6: PMTU exceptions - nexthop objects          [FAIL]
> > > # Cannot find device "ovs_br0"
> > > # TEST: IPv6, OVS geneve6: PMTU exceptions                            [FAIL]
> > > # Cannot find device "ovs_br0"
> > > 
> > > Any idea why? Looks like kernel config did include OVS, perhaps we need
> > > explicit modprobe now? I don't see any more details in the logs.
> > 
> > Strange.  I expected that the module should have automatically been
> > loaded when attempting to communicate with the OVS genetlink family
> > type.  At least, that is how it had been working previously.
> > 
> > I'll spend some time looking into it and resubmit a rebased version.
> > Thanks, Jakub!
> 
> If the ovs module isn't available, then I see:
> 
> #   ovs_bridge not supported
> # TEST: IPv4, OVS vxlan4: PMTU exceptions                             [SKIP]
> 
> But if it is available, I haven't been able to reproduce such ovs_br0
> setup failure - things work.

I'm still wondering if the issue is Kconfig-related (plus possibly bad
interaction with vng). I don't see the OVS knob enabled in the self-
tests config. If it's implied by some other knob, and ends-up being
selected as a module, vng could stumble upon loading the module at
runtime, especially on incremental build (at least I experience that
problem locally). I'm not even sure if the KCI is building
incrementally or not, so all the above could is quite a wild guess.

In any case I think adding the explicit CONFIG_OPENVSWITCH=y the
selftest config would make the scenario more well defined.

Cheers,

Paolo