Re: [PATCH net-next] selftests: forwarding: hw_stats_l3: Detect failure to install counters

[Hangbin Liu <liuhangbin@gmail.com>]

On Wed, Apr 05, 2023 at 04:25:12PM +0200, Petr Machata wrote:
> Running this test makes little sense if the enabled l3_stats are not
> actually reported as "used". This can signify a failure of a driver to
> install the necessary counters, or simply lack of support for enabling
> in-HW counters on a given netdevice. It is generally impossible to tell
> from the outside which it is. But more likely than not, if somebody is
> running this on veth pairs, they do not intend to actually test that a
> certain piece of HW can install in-HW counters for the veth. It is more
> likely they are e.g. running the test by mistake.
> 
> Therefore detect that the counter has not been actually installed. In that
> case, if the netdevice is one end of a veth pair, SKIP. Otherwise FAIL.
> 
> Suggested-by: Hangbin Liu <liuhangbin@gmail.com>
> Signed-off-by: Petr Machata <petrm@nvidia.com>
> Reviewed-by: Danielle Ratson <danieller@nvidia.com>
> ---
>  .../selftests/net/forwarding/hw_stats_l3.sh       | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/testing/selftests/net/forwarding/hw_stats_l3.sh b/tools/testing/selftests/net/forwarding/hw_stats_l3.sh
> index 9c1f76e108af..432fe8469851 100755
> --- a/tools/testing/selftests/net/forwarding/hw_stats_l3.sh
> +++ b/tools/testing/selftests/net/forwarding/hw_stats_l3.sh
> @@ -319,6 +319,19 @@ trap cleanup EXIT
>  setup_prepare
>  setup_wait
>  
> -tests_run
> +used=$(ip -j stats show dev $rp1.200 group offload subgroup hw_stats_info |
> +	   jq '.[].info.l3_stats.used')
> +kind=$(ip -j -d link show dev $rp1 |
> +	   jq -r '.[].linkinfo.info_kind')
> +if [[ $used != true ]]; then
> +	if [[ $kind == veth ]]; then
> +		log_test_skip "l3_stats not offloaded on veth interface"
> +		EXIT_STATUS=$ksft_skip
> +	else
> +		RET=1 log_test "l3_stats not offloaded"
> +	fi
> +else
> +	tests_run
> +fi
>  
>  exit $EXIT_STATUS
> -- 
> 2.39.0
> 

Tested-by: Hangbin Liu <liuhangbin@gmail.com>