Re: [PATCH 00/10] x86/fpu: APX enablement and assorted FPU code improvements

From: Ingo Molnar
Date: Wed Apr 16 2025 - 04:07:29 EST



* Chang S. Bae <chang.seok.bae@xxxxxxxxx> wrote:

> On 4/12/2025 1:43 AM, Ingo Molnar wrote:
> >
> > Chang, mind sending a series of the latest version of all the pending
> > APX patches you have at the moment (and any other pending FPU patches
> > you may have), with Reviewed-by tags rolled in, etc.
>
> Hi Ingo,
>
> Here’s the updated patch set following up on the previous APX series [1],
> along with a collection of additional FPU-related cleanups and
> improvements that were previously posted or discussed.
>
> The series is organized into two parts:
>
> 1. APX Enabling (PATCH 1–5)
>
> These patches complete the APX bring-up. After laying the groundwork,
> this portion finalizes the enablement:
>
> * Patches 1, 2, and 4 are typical xfeature plumbing.
>
> * Patch 3 handles MPX conflict -- unexpected hardware issue
>
> * Patch 5 adds a test case.
>
> 2. Miscellaneous FPU Code Improvements (PATCH 6–10)
>
> This batch includes various standalone improvements:
>
> * Patch 6: Centralizes the XSAVE disablement message
>
> * Patches 7-8: Simplifies PKRU update in XSTATE_BV on sigframe
>
> * Patch 9: Removes the unused mxcsr_feature_mask export
>
> * Patch 10: Renames fpu_reset_fpregs() for clarity
>
> Each patch includes context and links to earlier discussions or
> revisions.

> 14 files changed, 69 insertions(+), 26 deletions(-)

Applied to tip:x86/fpu, thanks!

Note that I've merged the currently pending tip:x86/cpu bits into
tip:x86/fpu before applying these patches, to resolve a conflict with
<asm/cpufeatures.h>, and re-formatted the new X86_FEATURE_APX line to
have the canonical format.


Ingo