Re: [PATCH 04/16] KVM: x86/mmu: Add address conversion functions for TDX shared bit of GPA

Edgecombe, Rick P
2024-05-16T23:08:18Z

On Wed, 2024-05-15 at 18:20 -0700, Rick Edgecombe wrote:
> On Thu, 2024-05-16 at 13:04 +1200, Huang, Kai wrote:
> >
> > I really don't see difference between ...
> >
> >         is_private_mem(gpa)
> >
> > ... and
> >
> >         is_private_gpa(gpa)
> >
> > If it confuses me, it can confuses other people.
>
> Again, point taken. I'll try to think of a better name. Please share if you
> do.

What about:
bool kvm_on_private_root(const struct kvm *kvm, gpa_t gpa);

Since SNP doesn't have a private root, it can't get confused for SNP. For TDX
it's a little weirder. We usually want to know if the GPA is to the private
half. Whether it's on a separate root or not is not really important to the
callers. But they could infer that if it's on a private root it must be a
private GPA.

Otherwise:
bool kvm_is_private_gpa_bits(const struct kvm *kvm, gpa_t gpa);

The bits indicates it's checking actual bits in the GPA and not the
private/shared state of the GFN.