Re: [patch V3 08/30] x86/microcode/intel: Save the microcode only after a successful late-load
From: Borislav Petkov
Date: Wed Sep 20 2023 - 10:42:24 EST
On Tue, Sep 12, 2023 at 09:57:56AM +0200, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>
> There are situations where the late microcode is loaded into memory, but is
> not applied:
>
> 1) The rendevouz fails
> 2) The microcode is rejected by the CPUs
>
> If any of this happens then the pointer which was updated at firmware load
> time is stale and subsequent CPU hotplug operations either fail to update
> or create inconsistent microcode state.
>
> Save the loaded microcode in a separate pointer from with the late load is
s/from with/before/
> attempted and when successful, update the hotplug pointer accordingly via a
> new micrcode_ops callback.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette