Re: x86/microcode/intel: Division by zero panic in 4.9.79 and 4.4.114

From: Borislav Petkov
Date: Tue Feb 06 2018 - 09:25:27 EST


On Tue, Feb 06, 2018 at 02:09:35PM +0000, Rolf Neugebauer wrote:
> The backport of 7e702d17ed1 ("x86/microcode/intel: Extend BDW
> late-loading further with LLC size check") to 4.9.79 and 4.4.14 causes
> a division by zero panic on some single vCPU machine types on Google
> Cloud (e.g. g1-small and n1-standard-1):

The microcode loader is not supposed to load in a guest.

Greg, I guess you need something like this:

a15a753539ec ("x86/microcode/AMD: Do not load when running on a hypervisor")

I haven't tried whether it applies cleanly though...

--
Regards/Gruss,
Boris.

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