Re: [PATCH v8 2/5] x86/cpuid: Add generic table for cpuid dependencies

[Andi Kleen]

On Fri, Oct 06, 2017 at 12:41:56AM +0200, Thomas Gleixner wrote:
> On Thu, 5 Oct 2017, Andi Kleen wrote:
> > +/*
> > + * Table of CPUID features that depend on others.
> > + *
> > + * This only includes dependencies that can be usefully disabled, not
> > + * features part of the base set (like FPU).
> > + */
> > +const static struct cpuid_dep cpuid_deps[] = {
> > +	{ X86_FEATURE_XSAVEOPT,		X86_FEATURE_XSAVE     },
> > +	{ X86_FEATURE_XSAVEC,		X86_FEATURE_XSAVE     },
> > +	{ X86_FEATURE_XSAVES,		X86_FEATURE_XSAVE     },
> > +	{ X86_FEATURE_AVX,		X86_FEATURE_XSAVE     },
> > +	{ X86_FEATURE_AVX512F,		X86_FEATURE_XSAVE     },
> 
> This looks redundant. AVX512F depends on AVX which itself depends on XSAVE.

True.

> 
> > +	{ X86_FEATURE_PKU,		X86_FEATURE_XSAVE     },
> > +	{ X86_FEATURE_MPX,		X86_FEATURE_XSAVE     },
> > +	{ X86_FEATURE_XGETBV1,		X86_FEATURE_XSAVE     },
> > +	{ X86_FEATURE_XMM2,		X86_FEATURE_XMM       },
> 
> XMM has no dependency?

Only FXSAVE, I'll add that.

Thanks,

-Andi