Subject: Re: [PATCH v3 net-next 10/10] selftests: net: tests for add double tunneling GRO/GSO

From: Petr Machata <[email-masked]>
Date: Thu, 15 Jan 2026 11:13:30 +0100

Paolo Abeni <[email-masked]> writes:

> Create a simple, netns-based topology with double, nested UDP tunnels and
> perform TSO transfers on top.
>
> Explicitly enable GSO and/or GRO and check the skb layout consistency with
> different configuration allowing (or not) GSO frames to be delivered on
> the other end.
>
> The trickest part is account in a robust way the aggregated/unaggregated
> packets with double encapsulation: use a classic bpf filter for it.
>
> Signed-off-by: Paolo Abeni <[email-masked]>

Looks OK overall, just:

> diff --git a/tools/testing/selftests/net/double_udp_encap.sh b/tools/testing/selftests/net/double_udp_encap.sh
> new file mode 100755
> index 000000000000..055f65b4d18d
> --- /dev/null
> +++ b/tools/testing/selftests/net/double_udp_encap.sh

> +# tcp retransmisions will break the accounting
> +[ "$KSFT_MACHINE_SLOW" = yes ] && FAIL_TO_XFAIL=yes

You should just be able to call `xfail_on_slow' without an argument to
apply the setting globally.

Selftests shouldn't have to touch FAIL_TO_XFAIL directly.