Re: [Xen-devel] [PATCH 02/12] early PV on HVM

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

On Fri, 4 Jun 2010, Konrad Rzeszutek Wilk wrote:
> > +static uint32_t xen_cpuid_base(void)
> > +{
> > +	uint32_t base, eax, ebx, ecx, edx;
> > +	char signature[13];
> > +
> > +	for (base = 0x40000000; base < 0x40010000; base += 0x100) {
> > +		cpuid(base, &eax, &ebx, &ecx, &edx);
> > +		*(uint32_t*)(signature + 0) = ebx;
> > +		*(uint32_t*)(signature + 4) = ecx;
> > +		*(uint32_t*)(signature + 8) = edx;
> > +		signature[12] = 0;
> > +
> > +		if (!strcmp("XenVMMXenVMM", signature) && ((eax - base) >= 2))
> > +			return base;
> > +	}
> > +
> > +	return 0;
> > +}
> 
> I forgot to mention this in the previous e-mail, but if you are rebasing
> this against 2.6.34 it might be worth taking a look at the Microsoft HyperV code.
> It also utilizes the cpuid code and this code could be made more generic.
> 

these patches are already based on 2.6.34, I didn't use the generic
hypervisor setup code because it is not available in 2.6.34, however
in the future rebasing to use that is going to be quite easy.