Re: Use CPUID to communicate with the hypervisor.

[Avi Kivity]

Nakajima, Jun wrote:
> On 9/29/2008 12:37:23 AM, Avi Kivity wrote:
>   
> > Gleb Natapov wrote:
> >     
> > > Can this interface be used to pass variable sized data from a
> > > hypervisor to a gust? ACPI or DMI tables for instance.
> > >
> > >       
> > In theory it can, but it would be a bad idea.  cpuid is best used to
> > communicate cpu features; ACPI and DMI are (mostly) system features.
> >     
>
> Also, we have reserved the MSRs from 0x40000000 - 0x400000FF for software use. We could use such MSRs, but what's the benefits of using those when ACPI already defined the detection mechanism?
>
>   

Features that the guest needs to enable very early on, before ACPI is 
up.  I don't think there are many of those.

--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

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