Re: [PATCHv10 04/18] cpu/hotplug, x86/acpi: Disable CPU offlining for ACPI MADT wakeup

From: Kirill A. Shutemov
Date: Wed Apr 24 2024 - 10:36:03 EST


On Wed, Apr 24, 2024 at 03:50:52PM +0200, Borislav Petkov wrote:
> On Wed, Apr 24, 2024 at 11:38:42AM +0300, Kirill A. Shutemov wrote:
> > It was wrong from beginning. If ACPI MADT wake up method is used on the
> > platform, we cannot handle offline, regardless if it is TDX or not.
>
> Sounds to me like this fact should be a prominent part of the commit
> message and these 1-4 patches should be carved out as a separate set
> fixing that ACPI MADT thing and I should take them separately now...?
>
> Also, does this need to go to stable although it is kinda big for
> stable. If stable, do we need a smaller fix first which is backportable?

Correct me, if I am wrong, but I believe TDX guest is the only user of
ACPI MADT wake up method. At least it was added into kernel for TDX guest.
So it wouldn't fix anything user-visible. It might affect a future
platform that uses this wake up method, but it is a guessing game.

--
Kiryl Shutsemau / Kirill A. Shutemov