Messages in this thread | | | Date | Wed, 17 Aug 2022 23:56:02 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH] x86/microcode/AMD: Attempt applying on every logical thread |
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On Wed, Aug 17, 2022 at 08:58:07PM +0000, Ashok Raj wrote: > For this specific patch in question, its not for testing though.. Its > required for functional purposes?
From its commit message:
"However, there are microcode patches which do per-thread modification, see Link tag below.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216211"
TL;DR - the application needs to happen on *every* logical CPU.
> In effect you can test applying the same microcode over and over again > without having any special patches.
Right now, you cannot downgrade on Zen but apparently applying the same patch over and over again works.
The patch cache still has a version check and that prevents it but that's ugly.
I need to test how it behaves on older families first and then think about how to do this right. Maybe use cpuinfo_x86.microcode to record what has been applied until now...
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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