Re: Hitting AUTOIBRS WARN_ON_ONCE() in init_amd() booting 32-bit kernel under KVM

[Josh Poimboeuf]

On Fri, Dec 06, 2024 at 08:20:06AM -0800, Sean Christopherson wrote:
> From: Sean Christopherson <seanjc@xxxxxxxxxx>
> Date: Fri, 6 Dec 2024 08:14:45 -0800
> Subject: [PATCH] x86/CPU/AMD: WARN when setting EFER.AUTOIBRS if and only if
>  the WRMSR fails
> 
> When ensuring EFER.AUTOIBRS is set, WARN only on a negative return code
> from msr_set_bit(), as '1' is used to indicate the WRMSR was successful
> ('0' indicates the MSR bit was already set).
> 
> Fixes: 8cc68c9c9e92 ("x86/CPU/AMD: Make sure EFER[AIBRSE] is set")
> Reported-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> Closes: https://lore.kernel.org/all/20241205220604.GA2054199@thelio-3990X
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>

LGTM, but please post as a proper patch in its own thread so the -tip
maintainers are more likely to see it.

-- 
Josh