Messages in this thread | | | Date | Wed, 16 Aug 2023 10:30:57 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH] x86/srso: Correct the mitigation status when SMT is disabled |
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On Tue, Aug 15, 2023 at 02:27:51PM -0700, Josh Poimboeuf wrote: > How is that relevant to my comment? The bug bit still wouldn't get set > and srso_show_state() still wouldn't be called.
Lemme explain how I see this working - it might help us get on the right track. And for comparison you can look at X86_FEATURE_BTC_NO too.
* Something has set X86_FEATURE_SRSO_NO - hw or sw doesn't matter - because the machine is not affected. X86_BUG_SRSO doesn't get set and the mitigation detection is skipped. All good.
* Nothing has set X86_FEATURE_SRSO_NO, mitigation detection runs and find that the kernel runs on a Zen1/2 with SMT disabled - we set X86_FEATURE_SRSO_NO.
* Now X86_FEATURE_SRSO_NO is passed in by KVM to the guest and the above dance repeats.
Now you.
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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