Re: [PATCH 1/3] selftests/resctrl: Add CPU vendor detection for Hygon

[Reinette Chatre <reinette.chatre@intel.com>]

Hi Xiaochen,

On 12/4/25 4:38 AM, Xiaochen Shen wrote:
> The resctrl selftest currently fails on Hygon CPUs that support Platform
> QoS features, printing the error:
> 
>   "# Can not get vendor info..."
> 
> This occurs because vendor detection is missing for Hygon CPUs.
> 
> Fix this by extending the CPU vendor detection logic to include
> Hygon's vendor ID.
> 
> Signed-off-by: Xiaochen Shen <shenxiaochen@open-hieco.net>
> ---
>  tools/testing/selftests/resctrl/resctrl.h       | 1 +
>  tools/testing/selftests/resctrl/resctrl_tests.c | 2 ++
>  2 files changed, 3 insertions(+)
> 
> diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
> index cd3adfc14969..df2a59e0141e 100644
> --- a/tools/testing/selftests/resctrl/resctrl.h
> +++ b/tools/testing/selftests/resctrl/resctrl.h
> @@ -38,6 +38,7 @@
>   */
>  #define ARCH_INTEL     1
>  #define ARCH_AMD       2
> +#define ARCH_HYGON     3

The comment before these defines attempts to provide guidance but it is clearly still
quite subtle that these values are required to be unique bits. Consider for example
their usage in test_vendor_specific_check():
	return get_vendor() & test->vendor_specific

This should either be 4 or a better solution is probably to switch all of these to use
BIT() (linux/bits.h is available via tools/include that is already in include path).

Reinette