static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
				     struct kvm_enable_cap *cap)
{
	int r;

	if (cap->flags)
		return -EINVAL;

	switch (cap->cap) {
	case KVM_CAP_S390_CSS_SUPPORT:
		if (!vcpu->kvm->arch.css_support) {
			vcpu->kvm->arch.css_support = 1;
			VM_EVENT(vcpu->kvm, 3, "%s", "ENABLE: CSS support");
			trace_kvm_s390_enable_css(vcpu->kvm);
		}
		r = 0;
		break;
	default:
		r = -EINVAL;
		break;
	}
	return r;
}