Re: [PATCH v3 2/6] KVM: arm64: maintain per VM value for CTR_EL0

[Sebastian Ott]

On Wed, 29 May 2024, Eric Auger wrote:
> On 5/29/24 17:51, Sebastian Ott wrote:
> > On Wed, 29 May 2024, Eric Auger wrote:
> > > > @@ -3557,6 +3557,13 @@ void kvm_reset_sys_regs(struct kvm_vcpu *vcpu)
> > > >      struct kvm *kvm = vcpu->kvm;
> > > >      unsigned long i;
> > > >
> > > > +    if (!kvm_vcpu_initialized(vcpu))
> > > at this stage of the reading, why is the above check needed?
> >
> > To make sure that a later call to this function doesn't overwrite
> > the value provided by userspace. (See e016333745c "KVM: arm64: Only
> > reset vCPU-scoped feature ID regs once").
> but isn't it overwritten through the .reset=reset_ctr() that is
> populated in next patch?

No, this is done via reset_vcpu_ftr_id_reg() and also guarded by
kvm_vcpu_initialized().

Sebastian