Re: [PATCH] x86/microcode/AMD: Attempt applying on every logical thread

From: Ashok Raj
Date: Wed Aug 17 2022 - 11:35:00 EST


On Wed, Aug 17, 2022 at 04:23:24PM +0200, Borislav Petkov wrote:
> On Wed, Aug 17, 2022 at 12:12:05PM +0000, Ashok Raj wrote:
> > Instead of doing a complete hack,
>
> What complete hack?!

What I meant was the patch removed any and all revid checks *completely*
Instead of even limiting to == checks.

Once you do that "in spirit" its the same end goal. Isn't it? Although it
might be required for a completely different reason.

>
> > could we maybe revive what we attempted
> > in 2019? At a minimum it will work for both architectures.
> >
> > https://lore.kernel.org/lkml/1567056803-6640-1-git-send-email-ashok.raj@xxxxxxxxx/
>
> echo 2 >... - now that's a hack.

Its all in the eye of the beholder :-)

I didn't mean in any way to bring back the echo 2. What ever you think is
suitable to enable this is fine.

>
> If you wanna use the kernel for testing your hw, use a local patch. Not
> expose it to people and then have me debug all kind of strange lockups.

So forget the hardware testing part. This is a complex flow for late-load
and how can we get more people to test it today in the community?

Do we have a more scalable way to support it today?

This is similar to XEN supporting, ucode=allow_same, there is precedence.

Doing that is just like having a built-in self-test for microcode loading.

I think there is value in enabling it for x86.

Cheers,
Ashok