Re: [PATCH v4 04/14] KVM: arm64: Use KVM extension checks for allowed protected VM capabilities

[Quentin Perret <qperret@google.com>]

On Monday 09 Dec 2024 at 08:14:15 (+0000), Fuad Tabba wrote:
> Hi Quentin,
> 
> On Fri, 6 Dec 2024 at 17:10, Quentin Perret <qperret@google.com> wrote:
> >
> > On Monday 02 Dec 2024 at 15:47:31 (+0000), Fuad Tabba wrote:
> > > diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c
> > > index fb733b36c6c1..59ff6aac514c 100644
> > > --- a/arch/arm64/kvm/hyp/nvhe/pkvm.c
> > > +++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c
> > > @@ -329,34 +329,20 @@ static void pkvm_init_features_from_host(struct pkvm_hyp_vm *hyp_vm, const struc
> > >
> > >       bitmap_zero(allowed_features, KVM_VCPU_MAX_FEATURES);
> > >
> > > -     /*
> > > -      * For protected VMs, always allow:
> > > -      * - CPU starting in poweroff state
> > > -      * - PSCI v0.2
> > > -      */
> > > -     set_bit(KVM_ARM_VCPU_POWER_OFF, allowed_features);
> >
> > For my understanding, why do we drop this bit?
> 
> Since the hypervisor is responsible for the power state of protected
> VMs. This should either be a separate patch or I should explain it in
> the commit message. Any preference?

Gotcha, perhaps make that its own patch so we have a commit message
motivating the change?