Re: [PATCH v7 033/102] KVM: x86/mmu: Add address conversion functions for TDX shared bits

Isaku Yamahata
2022-07-14T00:14:59Z

On Wed, Jul 13, 2022 at 10:41:33PM +1200,
Kai Huang <kai.huang@intel.com> wrote:

>
> > >
> > > And by applying this patch, nothing will prevent you to turn on INTEL_TDX_HOST
> > > and KVM_INTEL, which also turns on KVM_MMU_PRIVATE.
> > >
> > > So 'kvm_arch::gfn_shared_mask' is guaranteed to be 0? If not, can legal
> > > (shared) GFN for normal VM be potentially treated as private?
> > >
> > > If yes, perhaps explicitly call out in changelog so people don't need to worry
> > > about?
> >
> > struct kvm that includes struct kvm_arch is guaranteed to be zero.
> >
> > Here is the updated commit message.
> >
> > Author: Isaku Yamahata <isaku.yamahata@intel.com>
> > Date: Tue Jul 12 00:10:13 2022 -0700
> >
> > KVM: x86/mmu: Add address conversion functions for TDX shared bit of GPA
> >
> > TDX repurposes one GPA bit (51 bit or 47 bit based on configuration) to
> > indicate the GPA is private(if cleared) or shared (if set) with VMM. If
> > GPA.shared is set, GPA is converted existing conventional EPT pointed by
> > EPTP. If GPA.shared bit is cleared, GPA is converted by TDX module.
> > VMM has to issue SEAMCALLs to operate.
>
> Sorry what does "GPA is converted ..." mean?

Oops. typo. I meant GPA is covered by ...

--
Isaku Yamahata <isaku.yamahata@gmail.com>