KVM: s390: Move hardware setup/unsetup to init/exit

Now that kvm_arch_hardware_setup() is called immediately after
kvm_arch_init(), fold the guts of kvm_arch_hardware_(un)setup() into
kvm_arch_{init,exit}() as a step towards dropping one of the hooks.

No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20221130230934.1014142-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/s390/kvm/kvm-s390.c

@@ -331,21 +331,12 @@ static struct notifier_block kvm_clock_notifier = {
 
 int kvm_arch_hardware_setup(void *opaque)
 {
-	gmap_notifier.notifier_call = kvm_gmap_notifier;
-	gmap_register_pte_notifier(&gmap_notifier);
-	vsie_gmap_notifier.notifier_call = kvm_s390_vsie_gmap_notifier;
-	gmap_register_pte_notifier(&vsie_gmap_notifier);
-	atomic_notifier_chain_register(&s390_epoch_delta_notifier,
-				       &kvm_clock_notifier);
 	return 0;
 }
 
 void kvm_arch_hardware_unsetup(void)
 {
-	gmap_unregister_pte_notifier(&gmap_notifier);
-	gmap_unregister_pte_notifier(&vsie_gmap_notifier);
-	atomic_notifier_chain_unregister(&s390_epoch_delta_notifier,
-					 &kvm_clock_notifier);
+
 }
 
 static void allow_cpu_feat(unsigned long nr)
@@ -525,6 +516,13 @@ int kvm_arch_init(void *opaque)
 	if (rc)
 		goto err_gib;
 
+	gmap_notifier.notifier_call = kvm_gmap_notifier;
+	gmap_register_pte_notifier(&gmap_notifier);
+	vsie_gmap_notifier.notifier_call = kvm_s390_vsie_gmap_notifier;
+	gmap_register_pte_notifier(&vsie_gmap_notifier);
+	atomic_notifier_chain_register(&s390_epoch_delta_notifier,
+				       &kvm_clock_notifier);
+
 	return 0;
 
 err_gib:
@@ -541,6 +539,11 @@ int kvm_arch_init(void *opaque)
 
 void kvm_arch_exit(void)
 {
+	gmap_unregister_pte_notifier(&gmap_notifier);
+	gmap_unregister_pte_notifier(&vsie_gmap_notifier);
+	atomic_notifier_chain_unregister(&s390_epoch_delta_notifier,
+					 &kvm_clock_notifier);
+
 	kvm_s390_gib_destroy();
 	if (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM))
 		kvm_s390_pci_exit();