[PATCH v2 3/8] crypto: x86 - Stop using cpu_has_xfeatures()
Eric Biggers
ebiggers at kernel.org
Tue Jul 28 16:40:25 PDT 2026
On Tue, Jul 28, 2026 at 10:30:18AM +0100, David Laight wrote:
> On Mon, 27 Jul 2026 19:15:58 -0700
> Eric Biggers <ebiggers at kernel.org> wrote:
>
> > Checking both boot_cpu_has(X86_FEATURE_AVX*) and cpu_has_xfeatures() has
> > never really been needed in practice, and it's never been universally
> > done (e.g., lib/raid/ omits cpu_has_xfeatures()). Nevertheless, both
> > x86 and UML now explicitly clear the AVX and AVX-512 flags if their
> > xfeatures are missing, which should remove any remaining doubts.
> >
> > Thus, remove all the calls to cpu_has_xfeatures(), as well as the
> > related checks of boot_cpu_has(X86_FEATURE_OSXSAVE).
> >
> > In a few cases there was no corresponding boot_cpu_has(X86_FEATURE_AVX*)
> > check, so add the missing ones.
> >
> > Signed-off-by: Eric Biggers <ebiggers at kernel.org>
> > ---
> ...
> > --- a/arch/x86/crypto/aria_gfni_avx512_glue.c
> > +++ b/arch/x86/crypto/aria_gfni_avx512_glue.c
> > @@ -196,24 +196,15 @@ static struct skcipher_alg aria_algs[] = {
> >
> > static int __init aria_avx512_init(void)
> > {
> > - const char *feature_name;
> > -
> > if (!boot_cpu_has(X86_FEATURE_AVX) ||
> > !boot_cpu_has(X86_FEATURE_AVX2) ||
>
> Doesn't AVX2 require AVX support?
>
> > !boot_cpu_has(X86_FEATURE_AVX512F) ||
> > !boot_cpu_has(X86_FEATURE_AVX512VL) ||
>
> And (less sure) AVX512xxx require AVX2?
>
> So the extra checks could be reduced.
Yes, but this patch is just intended to clean up the xfeatures and
OSXSAVE checks. Further cleanups would be separate patches.
- Eric
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