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

[Maxim Levitsky]

On Fri, 2023-09-15 at 14:42 +0800, Yang, Weijiang wrote:
> 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.
> 
> 
My 0.2 cents are also on having XFEATURE_MASK_KERNEL_DYNAMIC macro instead.

Best regards,
	Maxim Levitsky