fix(logs): a row says what happened: a recovered migration, a failed clone step, a device not there

- A migration whose libvirt call failed but which recovery finds moved (or
  cannot tell) gets a row of that end; only a failure already logged by
  migrate_instance is not logged twice.
- A clone made with its resize or start failed, and a recovered migration
  whose autostart or NVRAM step failed, write a failed row of that step, as
  migrate_instance does for its later steps.
- Setting the link state of an interface or the video model of a VM that
  has none is refused: it changed nothing and was logged as done.
- The rows of a removed VM record (deleted or expired) name its host, VM
  and UUID, so the VM's history has them.

vrtManager/instance.py

@@ -1666,6 +1666,7 @@ class wvmInstance(wvmConnect):
                     new_model.set("primary", video_model.get("primary"))
                 self._defineXML(etree.tostring(tree).decode())
                 return
+        raise util.OperationError(gettext_noop("The VM has no video card"))
 
     def resize_cpu(self, cur_vcpu, vcpu):
         """
@@ -2940,14 +2941,18 @@ class wvmInstance(wvmConnect):
             raise util.OperationError(gettext_noop("The VM has no such USB device"))
 
     def set_link_state(self, mac_address, state):
+        found = False
         for xml_flags, affect in self._definitions():
             nic = self._nic(xml_flags, mac_address)
             if nic is None:
                 continue
+            found = True
             for link in nic.findall("link"):
                 nic.remove(link)
             etree.SubElement(nic, "link", state=state)
             self.instance.updateDeviceFlags(etree.tostring(nic).decode(), affect)
+        if not found:
+            raise util.OperationError(gettext_noop("The VM has no network interface %(mac)s"), mac=mac_address)
 
     def _set_options(self, tree, options):
         for o in ["title", "description"]:

vrtManager/tests/test_device_edits.py

@@ -110,6 +110,18 @@ class DeviceEditsTestCase(unittest.TestCase):
         self.assertEqual(model.attrib, {"type": "vga' heads='9"})
         p._defineXML.assert_called_once()
 
+    def test_a_device_the_vm_does_not_have_is_refused(self):
+        # a stale form: no change, and the audit row says it failed
+        p = proxy()
+        p._definitions = lambda: [(PERSISTENT_XML, VIR_DOMAIN_AFFECT_CONFIG)]
+        with self.assertRaisesRegex(util.OperationError, "no network interface 52:54:10:00:00:09"):
+            p.set_link_state("52:54:10:00:00:09", "down")
+        p._XMLDesc = lambda flags: PERSISTENT.replace("<video><model type='vga'/></video>", "")
+        with self.assertRaisesRegex(util.OperationError, "no video card"):
+            p.set_video_model("virtio")
+        p.instance.updateDeviceFlags.assert_not_called()
+        p._defineXML.assert_not_called()
+
     def test_qos_changes_go_through_define_xml(self):
         for change in (
             lambda p: p.set_qos("52:54:10:00:00:01", "outbound", 1, 2, 3),