Re: [PATCH net 1/4] ethtool: rss: fix hiding unsupported fields in dumps

[Joe Damato <jdamato@fastly.com>]

On Fri, Jan 31, 2025 at 05:30:37PM -0800, Jakub Kicinski wrote:
> Commit ec6e57beaf8b ("ethtool: rss: don't report key if device
> doesn't support it") intended to stop reporting key fields for
> additional rss contexts if device has a global hashing key.
> 
> Later we added dump support and the filtering wasn't properly
> added there. So we end up reporting the key fields in dumps
> but not in dos:
> 
>   # ./pyynl/cli.py --spec netlink/specs/ethtool.yaml --do rss-get \
> 		--json '{"header": {"dev-index":2}, "context": 1 }'
>   {
>      "header": { ... },
>      "context": 1,
>      "indir": [0, 1, 2, 3, ...]]
>   }
> 
>   # ./pyynl/cli.py --spec netlink/specs/ethtool.yaml --dump rss-get
>   [
>      ... snip context 0 ...
>      { "header": { ... },
>        "context": 1,
>        "indir": [0, 1, 2, 3, ...],
>  ->    "input_xfrm": 255,
>  ->    "hfunc": 1,
>  ->    "hkey": "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
>      }
>   ]
> 
> Hide these fields correctly.
> 
> The drivers/net/hw/rss_ctx.py selftest catches this when run on
> a device with single key, already:
> 
>   # Check| At /root/./ksft-net-drv/drivers/net/hw/rss_ctx.py, line 381, in test_rss_context_dump:
>   # Check|     ksft_ne(set(data.get('hkey', [1])), {0}, "key is all zero")
>   # Check failed {0} == {0} key is all zero
>   not ok 8 rss_ctx.test_rss_context_dump
> 
> Fixes: f6122900f4e2 ("ethtool: rss: support dumping RSS contexts")
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> ---
>  net/ethtool/rss.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Reviewed-by: Joe Damato <jdamato@fastly.com>