Re: [PATCH v11 3/4] x86/cpu: Do a sanity check on required feature bits

[Borislav Petkov]

On Mon, Mar 23, 2026 at 02:40:47PM -0700, H. Peter Anvin wrote:
> I did: the PAE case, which was not hypothetical. I'm sure I can dig up more.

So let's start our justification from this POV: we have use cases X and Y and they
would profit from getting these warning checks about required features not
being set.

I still am not persuaded that we want Linux to boot on those. Because those
CPUs are clearly "out of whack" and they would work by pure luck.

But I don't know anything about the particular snafus that happened there.

To take your example, the BIOS vendor disabled PAE. Do you really wanna deal
with fixing that? I mean, what else is b0rked there...?

So frankly, I'd turn that taint into a panic.

Because this CPU sounds to me like an all-bets-are-off thing.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette