Re: [PATCH v2] KVM: x86: use CPUID to locate host page table reserved bits

[Paolo Bonzini]

On 10/12/19 04:53, Huang, Kai wrote:
> Right. Alghouth both MKTME and SME/SEV reduce physical bits, but they treat
> those reduced bits differently: MKTME treats those as keyID thus they can be
> set, but SME/SEV treats those as reserved bits so you cannot set any of them.
> 
> Maybe the naming of shadow_phys_bits is a little bit confusing here. The purpose
> of it was to determine first reserved bits, but not actual physical address bits
> . Therefore for MKTME it should include the keyID bits, but for SME/SEV it
> should not.

Not just the first reserved bit, but _some_ reserved bit such that all
consecutive bits up to bit 51 are reserved.

Paolo