Re: [PATCH 06/23] x86/arch_prctl: Add controls for dynamic XSTATE components

From: Borislav Petkov
Date: Sun Oct 24 2021 - 17:17:43 EST


On Thu, Oct 21, 2021 at 03:55:10PM -0700, Chang S. Bae wrote:
> +/**
> + * fpu_xstate_prctl - xstate permission operations
> + * @tsk: Redundant pointer to current
> + * @option: A subfunction of arch_prctl()
> + * @arg2: option argument
> + * Return: 0 if successful; otherwise, an error code
> + *
> + * Option arguments:
> + *
> + * ARCH_GET_XCOMP_SUPP: Pointer to user space u64 to store the info
> + * ARCH_GET_XCOMP_PERM: Pointer to user space u64 to store the info
> + * ARCH_REQ_XCOMP_PERM: Facility number requested
> + *
> + * For facilities which require more than one XSTATE component, the request
> + * must be the highest state component number related to that facility,
> + * e.g. for AMX which requires XFEATURE_XTILE_CFG(17) and
> + * XFEATURE_XTILE_DATA(18) this would be XFEATURE_XTILE_DATA(18).
> + */

Can I pls get this new set of prctl()s documented properly ontop of this
patchset?

I guess Documentation/x86/xstate.rst or so.

Thx.

--
Regards/Gruss,
Boris.

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