Re: [PATCH 3.17 100/141] x86, microcode: Fix accessing dis_ucode_ldr on 32-bit

Konrad Rzeszutek Wilk
2014-11-25T20:37:22Z

On Tue, Nov 25, 2014 at 09:26:28PM +0100, Borislav Petkov wrote:
> On Tue, Nov 25, 2014 at 02:28:46PM -0500, Boris Ostrovsky wrote:
> > You'd have to decide at runtime --- many baremetal systems are
> > compiled with PARAVIRT.
>
> Right, but the microcode loader is not used at all on PV, right?

Is there an use-case for this in virtualization at all?
>
> If so, I'd like to add a arch_something_blabla_disabled_loader()
> function which is run in the loader init path and returns false on
> baremetal and a true when running as a xen guest. I'm not sure how the
> detection should be done, though... CPUID with the hypervisor leaf?

Why not make it in general then? Like:

if (cpu_has_hypervisor)
return;

?

>
> --
> Regards/Gruss,
> Boris.
>
> Sent from a fat crate under my desk. Formatting is fine.
> --