Re: [PATCH v3 1/5] KVM: x86: Expose Zhaoxin SM2 CPUID feature

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The newly added CPU feature flags `X86_FEATURE_SM2` and `X86_FEATURE_SM2_EN` in `arch/x86/include/asm/cpufeatures.h` are not mirrored to `tools/arch/x86/include/asm/cpufeatures.h`. This discrepancy triggers a 'Kernel ABI header ... differs from latest version' warning from `tools/perf/check-headers.sh` when building kernel tools.
--

commit 9ee6d6c060dd6911df4ff4999acdeb3563ea4667
Author: Ewan Hai-oc <ewanhai-oc@zhaoxin.com>

KVM: x86: Expose Zhaoxin SM2 CPUID feature

This commit advertises Zhaoxin SM2 instruction support to guests via
CPUID 0xC0000001 EDX bits 0 (SM2) and 1 (SM2_EN). It registers the new
capabilities in the KVM CPU caps initialization and the x86 architecture
feature lists.

> diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
> index 1d506e5d6f46a..20b33413189c2 100644
> --- a/arch/x86/include/asm/cpufeatures.h
> +++ b/arch/x86/include/asm/cpufeatures.h
> @@ -136,6 +136,8 @@
>  #define X86_FEATURE_HYPERVISOR		( 4*32+31) /* "hypervisor" Running on a hypervisor */
>  
>  /* VIA/Cyrix/Centaur-defined CPU features, CPUID level 0xC0000001, word 5 */
> +#define X86_FEATURE_SM2			( 5*32+ 0) /* "sm2" SM2 algorithm */
> +#define X86_FEATURE_SM2_EN		( 5*32+ 1) /* "sm2_en" SM2 enabled */

[Severity: Low]
This isn't a bug, but should these new feature flags also be added to
tools/arch/x86/include/asm/cpufeatures.h?

Leaving the tools copy out of sync with the main architecture header
triggers a warning from tools/perf/check-headers.sh indicating that the
Kernel ABI header differs from the latest version when building kernel
tools.

>  #define X86_FEATURE_XSTORE		( 5*32+ 2) /* "rng" RNG present (xstore) */
>  #define X86_FEATURE_XSTORE_EN		( 5*32+ 3) /* "rng_en" RNG enabled */

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260610023512.3690734-1-ewanhai-oc@zhaoxin.com?part=1