Re: Standardizing an MSR or other hypercall to get an RNG seed?

Paolo Bonzini
2014-09-18T17:17:50Z

Il 18/09/2014 19:13, Nakajima, Jun ha scritto:
> In terms of the address for the MSR, I suggest that you choose one
> from the range between 40000000H - 400000FFH. The SDM (35.1
> ARCHITECTURAL MSRS) says "All existing and
> future processors will not implement any features using any MSR in
> this range." Hyper-V already defines many synthetic MSRs in this
> range, and I think it would be reasonable for you to pick one for this
> to avoid a conflict?

KVM is not using any MSR in that range.

However, I think it would be better to have the MSR (and perhaps CPUID)
outside the hypervisor-reserved ranges, so that it becomes
architecturally defined. In some sense it is similar to the HYPERVISOR
CPUID feature.

Paolo