Re: [PATCH v6 06/25] x86/fpu/xstate: Opt-in kernel dynamic bits when calculate guest xstate size

[Edgecombe, Rick P]

On Thu, 2023-10-26 at 10:24 -0700, Sean Christopherson wrote:
> +       /*
> +        * Calculate the resulting kernel state size.  Note,
> @permitted also
> +        * contains supervisor xfeatures even though supervisor are
> always
> +        * permitted for kernel and guest FPUs, and never permitted
> for user
> +        * FPUs.

What is a user FPU vs kernel FPU in this context? By user FPU do you
mean, like user FPU state in a sigframe or something? Or a kernel
task's FPU? If the former I think this comment could be made more
clear. Maybe just drop the bit about user FPUs. At least the comment
makes more sense to me without it.