Re: [PATCH net-next 00/12] selftests: drv-net: convert GRO and Toeplitz tests to work for drivers in NIPA

[Jakub Kicinski <kuba@kernel.org>]

On Mon, 17 Nov 2025 21:11:31 -0500 Willem de Bruijn wrote:
> > Note that neither GRO nor the Toeplitz test fully passes for me on
> > any HW I have access to. But this is unrelated to the conversion.  
> 
> You observed the same failures with the old and new tests? Are they
> deterministic failures or flakes.

Deterministic for Toeplitz - all NICs I have calculate the Rx 
hash the same as the test for at least one of traffic types. 
But none of them exactly as the test is expecting.
One IIRC also uses non-standard RSS indir table pattern by default.
The indirection table will be a trivial fix.

For HW-GRO I investigated less closely I mostly focused on making sure
netdevsim is solid as a replacement for veth. There was more flakiness
on HW (admittedly I was running inter-dc-building). But the failures
looked rather sus - the test was reporting that packets which were
not supposed to be coalesced got coalesced.

BTW it's slightly inconvenient that we disable HW-GRO when normal GRO
is disabled :( Makes it quite hard to run the test to check device
behavior. My current plan is to rely on device counters to check
whether traffic is getting coalesced but better ideas most welcome :(

> > This series is not making any real functional changes to the tests,
> > it is limited to improving the "test harness" scripts.
> 
> No significant actionable comments, just a few trivial typos.

Thanks!