Re: [PATCH 07/12] KVM: x86: SEV: Treat C-bit as legal GPA bit regardless of vCPU mode

[Paolo Bonzini]

On 04/02/21 03:19, Sean Christopherson wrote:
> Ah, took me a few minutes, but I see what you're saying.  LAM will introduce
> bits that are repurposed for CR3, but not generic GPAs.  And, the behavior is
> based on CPU support, so it'd make sense to have a mask cached in vcpu->arch
> as opposed to constantly generating it on the fly.
>
> Definitely agree that having a separate cr3_lm_rsvd_bits or whatever is the
> right way to go when LAM comes along.  Not sure it's worth keeping a duplicate
> field in the meantime, though it would avoid a small amount of thrash.

We don't even know if the cr3_lm_rsvd_bits would be a field in 
vcpu->arch, or rather computed on the fly.  So renaming the field in 
vcpu->arch seems like the simplest thing to do now.

Paolo