KVM: s390: enable STFLE interpretation only if enabled for the guest

Not setting the facility list designation disables STFLE interpretation,
this is what we want if the guest was told to not have it.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

arch/s390/kvm/kvm-s390.c

@@ -1639,7 +1639,8 @@ static void kvm_s390_vcpu_setup_model(struct kvm_vcpu *vcpu)
 
 	vcpu->arch.cpu_id = model->cpu_id;
 	vcpu->arch.sie_block->ibc = model->ibc;
-	vcpu->arch.sie_block->fac = (int) (long) model->fac->list;
+	if (test_kvm_facility(vcpu->kvm, 7))
+		vcpu->arch.sie_block->fac = (int) (long) model->fac->list;
 }
 
 int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)