Re: [PATCH -v2.1] x86/msr: Filter MSR writes

[Mathieu Chouquet-Stringer]

On Tue, Nov 17, 2020 at 10:20:16PM +0100, Borislav Petkov wrote:
> Not for long:
> 
> https://git.kernel.org/tip/fe0a5788624c8b8f113a35bbe4636e37f9321241

That's fantastic.

> Because if you poke at random MSRs and you manage to "configure" your
> CPU to run "out of spec" - this is what the taint flag is called:
> TAINT_CPU_OUT_OF_SPEC - then this is exactly the case you've created: a
> CPU executing outside of specifications.

Don't get me wrong, it makes total sense to do that, it's just the
original reason of !SMP-capable isn't so clear while CPU out of spec is.

-- 
Mathieu Chouquet-Stringer                             me@mathieu.digital
            The sun itself sees not till heaven clears.
	             -- William Shakespeare --