Re: [PATCHv6 01/16] x86/cpu: Enumerate the LASS feature bits

Kirill A. Shutemov
2025-06-20T17:33:48Z

On Fri, Jun 20, 2025 at 06:35:04PM +0200, Borislav Petkov wrote:
> On Fri, Jun 20, 2025 at 04:53:09PM +0300, Kirill A. Shutemov wrote:
> > diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
> > index ee176236c2be..4473a6f7800b 100644
> > --- a/arch/x86/include/asm/cpufeatures.h
> > +++ b/arch/x86/include/asm/cpufeatures.h
> > @@ -313,6 +313,7 @@
> > #define X86_FEATURE_SM4 (12*32+ 2) /* SM4 instructions */
> > #define X86_FEATURE_AVX_VNNI (12*32+ 4) /* "avx_vnni" AVX VNNI instructions */
> > #define X86_FEATURE_AVX512_BF16 (12*32+ 5) /* "avx512_bf16" AVX512 BFLOAT16 instructions */
> > +#define X86_FEATURE_LASS (12*32+ 6) /* "lass" Linear Address Space Separation */
>
> This needs to be in /proc/cpuinfo because...?

What is current policy around it ?

I think it is useful to advertise security features in cpuinfo. LASS fits
next to SMAP/SMEP/UMIP.

--
Kiryl Shutsemau / Kirill A. Shutemov