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

Paolo Bonzini
2014-09-19T16:22:24Z

Il 19/09/2014 18:14, Nakajima, Jun ha scritto:
> For example,
> - CPUID 0x48000001.EAX would return the feature presence (e.g. in
> EBX), and the result in EDX:EAX (if present) at the same time, or
> - CPUID 0x48000001.EAX would return the feature presence only, and
> CPUID 0x48000002.EAX (acts like a hypercall) returns up to 4 32-bit
> values.

The latter is much better, because an "unknown" CPUID will return the
value of the highest leaf below 0x80000000, and conflicts can happen easily.

Paolo