Re: [PATCH net-next v3 0/4] selftests: drv-net: rss_ctx: add tests for RSS contexts

[Jakub Kicinski <kuba@kernel.org>]

On Wed, 26 Jun 2024 17:50:20 +0100 Edward Cree wrote:
> On 26/06/2024 02:24, Jakub Kicinski wrote:
> > Ed, could you try the tests with your device?  
> 
> Don't seem to be able to get them to run:
> 
> # Exception| Traceback (most recent call last):
> # Exception|   File "/home/ecree/kern/linux/tools/testing/selftests/net/lib/py/ksft.py", line 134, in ksft_run
> # Exception|     case(*args)
> # Exception|   File "./drivers/net/hw/rss_ctx.py", line 70, in test_rss_key_indir
> # Exception|     if len(_get_rx_cnts(cfg)) < 2:
> # Exception|   File "./drivers/net/hw/rss_ctx.py", line 55, in _get_rx_cnts
> # Exception|     data = cfg.netdevnl.qstats_get({"ifindex": cfg.ifindex, "scope": ["queue"]}, dump=True)
> # Exception|   File "/home/ecree/kern/linux/tools/net/ynl/lib/ynl.py", line 1029, in _op
> # Exception|     return self._ops(ops)[0]
> # Exception|   File "/home/ecree/kern/linux/tools/net/ynl/lib/ynl.py", line 985, in _ops
> # Exception|     raise NlError(nl_msg)
> # Exception| net.ynl.lib.ynl.NlError: Netlink error: Operation not supported
> # Exception| nl_len = 28 (12) nl_flags = 0x202 nl_type = 3
> # Exception| 	error: -95
> # Exception| 	extack: {'bad-attr': '.ifindex'}
> not ok 1 rss_ctx.test_rss_key_indir
> 
> Cursory investigation suggests this is because sfc doesn't
>  support netdev_stat_ops, we're still living in the bad old
>  days of ethtool -S for our per-queue stats :(

Ugh, right, the standard stats turn out to be key in a large number 
of the tests we end up writing. Perhaps unsurprisingly :(

Fetching stats is done only in _get_rx_cnts(), so you could possibly
do a quick hack there to parse ethtool -S, just to test the test.
But maybe that'd just lead you to another gap..

> Much as I'd like to fix that, I don't see a prospect of the
>  folks upstairs carving out time for it any time soon...

Sadness. Makes me worried that they won't care about maintaining
the Supported status of the driver either :( (Which is not to say
that implementing qstats is a requirement there.)

Anyway, thanks for giving it a go. I'm fairly confident now that
the failures I see are a device / driver bug. So we can merge
the test and let the various drivers address the gaps.

BTW, while I have you, there are two more bits of work:
 - get + dump API via netlink
 - set API via netlink
are you planning to work on those?