Re: [PATCH v2 14/22] x86/fpu/xstate: Inherit dynamic user state when used in the parent

[Andy Lutomirski]

On Thu, Nov 19, 2020 at 3:37 PM Chang S. Bae <chang.seok.bae@xxxxxxxxx> wrote:
>
> When a new task is created, the kernel copies all the states from the
> parent. If the parent already has any dynamic user state in use, the new
> task has to expand the XSAVE buffer to save them. Also, disable the
> associated first-use fault.

This seems like a mistake.  If init uses AMX for some misguided
reason, ever task on the whole system will end up with AMX state
allocated.