Re: [PATCH v3 0/8] x86: Remove cpu_has_xfeatures() and add AVX-512 xor_gen()

[Borislav Petkov]

On Wed, Aug 12, 2026 at 07:14:58PM -0700, Eric Biggers wrote:
> This series consolidates and cleans up how the kernel handles CPU
> feature flags for AVX and AVX-512 when the underlying OS or hypervisor
> (if any) doesn't enable the required xstate features in XCR0.
> 
> Specifically, it makes the checks for xstate features be done in a
> single place at boot time for both UML and native x86, instead of
> everywhere kernel code wants to check for AVX or AVX-512 support.
> 
> Patch 8 then adds an AVX-512 optimized implementation of xor_gen() for
> RAID, which had been blocked on confusion around cpu_has_xfeatures() and
> its lack of implementation on UML.

Sashiko complains about a missing VZEROUPPER there in patch 8:

https://sashiko.dev/#/patchset/20260813021506.55129-1-ebiggers%40kernel.org

Otherwise, LGTM.

I can queue them all into tip after the merge window opens.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette