Re: [RFC][PATCH 06/17] x86/cpu: Add SRSO untrain to retbleed=

From: Peter Zijlstra
Date: Sat Aug 12 2023 - 07:33:21 EST


On Fri, Aug 11, 2023 at 12:27:48PM +0200, Borislav Petkov wrote:
> On Thu, Aug 10, 2023 at 12:10:03PM -0400, Josh Poimboeuf wrote:
> > I tend to agree that SRSO is a new issue and should have its own sysfs
> > and cmdline options (though a separate CONFIG option is overkill IMO).
>
> Yeah, there's a patch floating around adding a config option for every
> mitigation. Apparently people want to build-time disable them all.

So I really hate that .Kconfig explosion, that's the very last thing we
need :-( More random options that can cause build time trouble.

I might see value in one knob that kills all speculation nonsense at
build time, but not one per mitigation, that's maddness.