Re: [PATCH v6 04/25] x86/fpu/xstate: Introduce kernel dynamic xfeature set

[Yang, Weijiang]

On 9/15/2023 8:24 AM, Edgecombe, Rick P wrote:
> On Thu, 2023-09-14 at 02:33 -0400, Yang Weijiang wrote:
> > +static void __init init_kernel_dynamic_xfeatures(void)
> > +{
> > +       unsigned short cid;
> > +       int i;
> > +
> > +       for (i = 0; i < ARRAY_SIZE(xsave_kernel_dynamic_xfeatures);
> > i++) {
> > +               cid = xsave_kernel_dynamic_xfeatures[i];
> > +
> > +               if (cid && boot_cpu_has(cid))
> > +                       fpu_kernel_dynamic_xfeatures |= BIT_ULL(i);
> > +       }
> > +}
> > +
> I think this can be part of the max_features calculation that uses
> xsave_cpuid_features when you use use a fixed mask like Dave suggested
> in the other patch.

Yes, the max_features has already included CET supervisor state bit. After  use
fixed mask, this function is not needed.