Re: [PATCH v3 7/7] KVM: x86: SVM: allow AVIC to co-exist with a nested guest running

[Paolo Bonzini]

On 3/1/22 15:36, Maxim Levitsky wrote:
>   	bool activate;
> @@ -9690,7 +9695,9 @@ void kvm_vcpu_update_apicv(struct kvm_vcpu *vcpu)
>   
>   	down_read(&vcpu->kvm->arch.apicv_update_lock);
>   
> -	activate = kvm_apicv_activated(vcpu->kvm);
> +	activate = kvm_apicv_activated(vcpu->kvm) &&
> +		   !vcpu_has_apicv_inhibit_condition(vcpu);
> +
>   	if (vcpu->arch.apicv_active == activate)
>   		goto out;
>   

Perhaps the callback could be named vcpu_apicv_inhibit_reasons, and it would
return APICV_INHIBIT_REASON_NESTED?  Then instead of the new function
vcpu_has_apicv_inhibit_condition(), you would have

bool kvm_vcpu_apicv_activated(struct vcpu_kvm *kvm)
{
	ulong vm_reasons = READ_ONCE(vcpu->kvm->arch.apicv_inhibit_reasons);
	ulong vcpu_reasons = static_call(kvm_x86_vcpu_apicv_inhibit_reasons)(vcpu);
        return (vm_reasons | vcpu_reasons) == 0;
}
EXPORT_SYMBOL_GPL(kvm_cpu_apicv_activated);

It's mostly aesthetics, but it would also be a bit more self explanatory I think.

Paolo