Re: [PATCH v2 1/8] x86/fpu: Check for missing AVX and AVX-512 xstate bits

[Borislav Petkov]

On Wed, Aug 12, 2026 at 07:40:11PM +0000, Eric Biggers wrote:
> Interesting, so the !boot_cpu_has(X86_FEATURE_FPU) check is dead code
> since ab05214025ee ("x86/fpu: Remove MATH_EMULATION and related glue
> code").  Sure, there's no need to add anything to there then, though we
> should do a separate patch that removes it.

Sure.

> Sure, that works.  I'm not sure it's actually easier to understand than
> what I proposed; it's kind of contradictory to call
> "setup_clear_cpu_cap(X86_FEATURE_XSAVE)" when we just verified it is
> clear.  But the comment mentioning that it's actually for clearing
> dependent flags helps.  If you prefer this way, let's do this.

Yes please, that's why I added the comment. And we have this machinery in
do_clear_cpu_cap() so let's use it.

> It's functionally equivalent, but yes we can write it this way if you
> prefer.  Is it okay if I fold your diff (minus the pr_info()) into this
> patch?  (I'll also add FW_BUG to the error messages as Thomas
> requested.)

Yap, that's perfectly fine.

Thanks.

-- 
Regards/Gruss,
    Boris.

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