Re: [PATCH v2 08/17] kvm: arm/arm64: Prepare for VM specific stage2 translations

[Julien Grall]

Hi Suzuki,

On 27/04/18 16:58, Suzuki K Poulose wrote:
> On 27/04/18 16:22, Suzuki K Poulose wrote:
> > On 26/04/18 14:35, Julien Grall wrote:
> > > Hi Suzuki,
> > >
> > > On 27/03/18 14:15, Suzuki K Poulose wrote:
> > > > Right now the stage2 page table for a VM is hard coded, assuming
> > > > an IPA of 40bits. As we are about to add support for per VM IPA,
> > > > prepare the stage2 page table helpers to accept the kvm instance
> > > > to make the right decision for the VM. No functional changes.
> >
> >
> > > > diff --git a/arch/arm/include/asm/kvm_arm.h 
> > > > b/arch/arm/include/asm/kvm_arm.h
> > > > index 3ab8b37..c3f1f9b 100644
> > > > --- a/arch/arm/include/asm/kvm_arm.h
> > > > +++ b/arch/arm/include/asm/kvm_arm.h
> > > > @@ -133,8 +133,7 @@
> > > > ÂÂ * space.
> > > > ÂÂ */
> > > > Â #define KVM_PHYS_SHIFTÂÂÂ (40)
> > > > -#define KVM_PHYS_SIZEÂÂÂ (_AC(1, ULL) << KVM_PHYS_SHIFT)
> > > > -#define KVM_PHYS_MASKÂÂÂ (KVM_PHYS_SIZE - _AC(1, ULL))
> > >
> > > I assume you are moving them to kvm_mmu.h in order to match the arm64 
> > > side, right? If so, would not it make sense to make KVM_PHYS_SHIFT 
> > > with it?
> > >
> > > [...]
> >
> > I am moving all the macros that depend on the "kvm" instance to 
> > kvm_mmu.h.
> > I will see if I can move the KVM_PHYS_SHIFT without much trouble.
>
> It looks like we can't do that easily. KVM_PHYS_SHIFT is used for KVM_T0SZ
> on arm, even though that can be simply hard coded to avoid the 
> dependency on
> KVM_PHYS_SHIFT (like we did for arm64, T0SZ is defined to 24). I would 
> leave it
> as it is to avoid the noise.

Fine. That was only a suggestion :).

Cheers,

--
Julien Grall