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Diffstat (limited to 'arch/s390/kvm/kvm-s390.c')
-rw-r--r--arch/s390/kvm/kvm-s390.c31
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 5b77c43fbb01..5d18b66a08c9 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1763,6 +1763,32 @@ static int kvm_s390_get_cpu_model(struct kvm *kvm, struct kvm_device_attr *attr)
 	return ret;
 }
 
+/**
+ * kvm_s390_update_topology_change_report - update CPU topology change report
+ * @kvm: guest KVM description
+ * @val: set or clear the MTCR bit
+ *
+ * Updates the Multiprocessor Topology-Change-Report bit to signal
+ * the guest with a topology change.
+ * This is only relevant if the topology facility is present.
+ *
+ * The SCA version, bsca or esca, doesn't matter as offset is the same.
+ */
+static void kvm_s390_update_topology_change_report(struct kvm *kvm, bool val)
+{
+	union sca_utility new, old;
+	struct bsca_block *sca;
+
+	read_lock(&kvm->arch.sca_lock);
+	sca = kvm->arch.sca;
+	do {
+		old = READ_ONCE(sca->utility);
+		new = old;
+		new.mtcr = val;
+	} while (cmpxchg(&sca->utility.val, old.val, new.val) != old.val);
+	read_unlock(&kvm->arch.sca_lock);
+}
+
 static int kvm_s390_vm_set_attr(struct kvm *kvm, struct kvm_device_attr *attr)
 {
 	int ret;
@@ -3172,6 +3198,7 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
 	kvm_clear_async_pf_completion_queue(vcpu);
 	if (!kvm_is_ucontrol(vcpu->kvm))
 		sca_del_vcpu(vcpu);
+	kvm_s390_update_topology_change_report(vcpu->kvm, 1);
 
 	if (kvm_is_ucontrol(vcpu->kvm))
 		gmap_remove(vcpu->arch.gmap);
@@ -3574,6 +3601,8 @@ static int kvm_s390_vcpu_setup(struct kvm_vcpu *vcpu)
 		vcpu->arch.sie_block->ecb |= ECB_HOSTPROTINT;
 	if (test_kvm_facility(vcpu->kvm, 9))
 		vcpu->arch.sie_block->ecb |= ECB_SRSI;
+	if (test_kvm_facility(vcpu->kvm, 11))
+		vcpu->arch.sie_block->ecb |= ECB_PTF;
 	if (test_kvm_facility(vcpu->kvm, 73))
 		vcpu->arch.sie_block->ecb |= ECB_TE;
 	if (!kvm_is_ucontrol(vcpu->kvm))
@@ -3707,6 +3736,8 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 	rc = kvm_s390_vcpu_setup(vcpu);
 	if (rc)
 		goto out_ucontrol_uninit;
+
+	kvm_s390_update_topology_change_report(vcpu->kvm, 1);
 	return 0;
 
 out_ucontrol_uninit: