static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data)
{
	gpa_t gpa = data & ~0x3f;

	/* Bits 4:5 are reserved, Should be zero */
	if (data & 0x30)
		return 1;

	if (!guest_pv_has(vcpu, KVM_FEATURE_ASYNC_PF_VMEXIT) &&
	    (data & KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT))
		return 1;

	if (!guest_pv_has(vcpu, KVM_FEATURE_ASYNC_PF_INT) &&
	    (data & KVM_ASYNC_PF_DELIVERY_AS_INT))
		return 1;

	if (!lapic_in_kernel(vcpu))
		return data ? 1 : 0;

	vcpu->arch.apf.msr_en_val = data;

	if (!kvm_pv_async_pf_enabled(vcpu)) {
		kvm_clear_async_pf_completion_queue(vcpu);
		kvm_async_pf_hash_reset(vcpu);
		return 0;
	}

	if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.apf.data, gpa,
					sizeof(u64)))
		return 1;

	vcpu->arch.apf.send_user_only = !(data & KVM_ASYNC_PF_SEND_ALWAYS);
	vcpu->arch.apf.delivery_as_pf_vmexit = data & KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT;

	kvm_async_pf_wakeup_all(vcpu);

	return 0;
}
static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data)
{
	gpa_t gpa = data & ~0x3f;

	 
	if (data & 0x30)
		return 1;

	if (!guest_pv_has(vcpu, KVM_FEATURE_ASYNC_PF_VMEXIT) &&
	    (data & KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT))
		return 1;

	if (!guest_pv_has(vcpu, KVM_FEATURE_ASYNC_PF_INT) &&
	    (data & KVM_ASYNC_PF_DELIVERY_AS_INT))
		return 1;

	if (!lapic_in_kernel(vcpu))
		return data ? 1 : 0;

	vcpu->arch.apf.msr_en_val = data;

	if (!kvm_pv_async_pf_enabled(vcpu)) {
		kvm_clear_async_pf_completion_queue(vcpu);
		kvm_async_pf_hash_reset(vcpu);
		return 0;
	}

	if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.apf.data, gpa,
					sizeof(u64)))
		return 1;

	vcpu->arch.apf.send_user_only = !(data & KVM_ASYNC_PF_SEND_ALWAYS);
	vcpu->arch.apf.delivery_as_pf_vmexit = data & KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT;

	kvm_async_pf_wakeup_all(vcpu);

	return 0;
}