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

[Edgecombe, Rick P]

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.