Re: [PATCH v1 00/12] x86/mce: Correct the noinstr annotation

From: Peter Zijlstra
Date: Thu Dec 09 2021 - 07:20:05 EST


On Wed, Dec 08, 2021 at 12:13:31PM +0100, Borislav Petkov wrote:
> From: Borislav Petkov <bp@xxxxxxx>
>
> Hi folks,
>
> here's v1 with the instrumentation "sandwiching" documented, as
> requested by peterz.
>
> Tony, I'd appreciate making sure nothing in them breaks your injection
> workflows before I queue them. And it shouldn't but... :-)
>
> Thx.
>
> Changelog:
> ==========
>
> here's a first preliminary (it is based on some random 5.16-rc0 commit
> and is tested only in qemu) of the series which correct all the noinstr
> annotation of the #MC handler.
>
> Since it calls a bunch of external facilities, the strategy is to mark
> mce-specific functions called by the #MC handler as noinstr and when
> they "call out" so to speak, to do a begin/end sandwich around that
> call.
>

Looked ok. I think some of the comments can be improved to clarify the
noinstr usage in MCE in general, but that's about it.