Re: [RFC PATCH v2 09/10] KVM: arm64: arm64 has private memory support when config is enabled

[Fuad Tabba <tabba@google.com>]

Hi Patrick,

On Thu, 15 Aug 2024 at 07:27, Patrick Roy <roypat@amazon.co.uk> wrote:
>
> Hi Fuad,
>
> On Thu, 2024-08-01 at 10:01 +0100, Fuad Tabba wrote:
> > Implement kvm_arch_has_private_mem() in arm64, making it
> > dependent on the configuration option.
> >
> > Signed-off-by: Fuad Tabba <tabba@google.com>
> > ---
> >  arch/arm64/include/asm/kvm_host.h | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> > index 36b8e97bf49e..8f7d78ee9557 100644
> > --- a/arch/arm64/include/asm/kvm_host.h
> > +++ b/arch/arm64/include/asm/kvm_host.h
> > @@ -1414,4 +1414,7 @@ bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu);
> >                 (pa + pi + pa3) == 1;                                   \
> >         })
> >
> > +#define kvm_arch_has_private_mem(kvm)                                  \
> > +       (IS_ENABLED(CONFIG_KVM_PRIVATE_MEM) && is_protected_kvm_enabled())
> > +
>
> Would it make sense to have some ARM equivalent of
> KVM_X86_SW_PROTECTED_VM here? Both for easier testing of guest_memfd on
> ARM, as well as for future non-coco usecases.

I don't really have a strong opinion about this. I thought that
if/when that were to happen, it would be trivial to modify this macro.

Cheers,
/fuad

> >  #endif /* __ARM64_KVM_HOST_H__ */
> > --
> > 2.46.0.rc1.232.g9752f9e123-goog
> >
>
> Best,
> Patrick