From: David Hildenbrand <david@redhat.com>

device_del on a CPU will currently do nothing. Let's emit an error
telling that this is will currently not work (there is no architecture
support on s390x). Error message copied from ppc.

(qemu) device_del cpu1
device_del cpu1
CPU hot unplug not supported on this machine

Reviewed-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170913132417.24384-18-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
---
 hw/s390x/s390-virtio-ccw.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index 99c36a1315..acdd53573c 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -339,6 +339,15 @@ static void s390_machine_device_plug(HotplugHandler *hotplug_dev,
     }
 }
 
+static void s390_machine_device_unplug_request(HotplugHandler *hotplug_dev,
+                                               DeviceState *dev, Error **errp)
+{
+    if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
+        error_setg(errp, "CPU hot unplug not supported on this machine");
+        return;
+    }
+}
+
 static HotplugHandler *s390_get_hotplug_handler(MachineState *machine,
                                                 DeviceState *dev)
 {
@@ -388,6 +397,7 @@ static void ccw_machine_class_init(ObjectClass *oc, void *data)
     mc->max_cpus = 248;
     mc->get_hotplug_handler = s390_get_hotplug_handler;
     hc->plug = s390_machine_device_plug;
+    hc->unplug_request = s390_machine_device_unplug_request;
     nc->nmi_monitor_handler = s390_nmi;
 }
 
-- 
2.13.5