Merge: Fix a problem with the time handling of nested KVM guests

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/1750

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2140899

Nested guests on s390x encounter a mixed up system time in some cases (like rebooting
or after migration of the host KVM guest). This patch fixes the problem.

Signed-off-by: Thomas Huth <thuth@redhat.com>

Approved-by: Cédric Le Goater <clg@redhat.com>
Approved-by: David Hildenbrand <david@redhat.com>
Approved-by: Cornelia Huck <cohuck@redhat.com>

Signed-off-by: Herton R. Krzesinski <herton@redhat.com>

Author: Herton R. Krzesinski

arch/s390/kvm/vsie.c

@@ -546,8 +546,10 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 	if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_CEI))
 		scb_s->eca |= scb_o->eca & ECA_CEI;
 	/* Epoch Extension */
-	if (test_kvm_facility(vcpu->kvm, 139))
+	if (test_kvm_facility(vcpu->kvm, 139)) {
 		scb_s->ecd |= scb_o->ecd & ECD_MEF;
+		scb_s->epdx = scb_o->epdx;
+	}
 
 	/* etoken */
 	if (test_kvm_facility(vcpu->kvm, 156))