Re: [PATCH v19 052/130] KVM: x86/mmu: Track shadow MMIO value on a per-VM basis

Isaku Yamahata
2024-03-27T23:58:35Z

On Tue, Mar 26, 2024 at 03:31:05AM +0000,
"Edgecombe, Rick P" <rick.p.edgecombe@intel.com> wrote:

> On Mon, 2024-02-26 at 00:25 -0800, isaku.yamahata@intel.com wrote:
> > From: Isaku Yamahata <isaku.yamahata@intel.com>
> >
> > TDX will use a different shadow PTE entry value for MMIO from VMX.  Add
> > members to kvm_arch and track value for MMIO per-VM instead of global
> > variables.  By using the per-VM EPT entry value for MMIO, the existing VMX
> > logic is kept working.  Introduce a separate setter function so that guest
> > TD can override later.
> >
> > Also require mmio spte caching for TDX.
>
>
> > Actually this is true case
> > because TDX requires EPT and KVM EPT allows mmio spte caching.
> >
>
> I can't understand what this is trying to say.

I'll drop this sentence as the logic moved to
"069/130 KVM: TDX: Require TDP MMU and mmio caching for TDX".

> >  {
> > +
> > +       kvm->arch.shadow_mmio_value = shadow_mmio_value;
>
> It could use kvm_mmu_set_mmio_spte_value()?

Yes.
--
Isaku Yamahata <isaku.yamahata@intel.com>