qmp: reboot if try to reduce memory size

slapos/qemuqmpclient/__init__.py

@@ -53,7 +53,7 @@ def parseArgument():
   parser.add_argument('--device-options', dest='device_options',
     help="Option used for update-device:\n" \
       '"device=cpu,amount=VALUE_INT[,model=MODEL]"\n OR '\
-      '"device=memory,mem=VALUE_MB[,slot=VALUE_MB],nslot=VALUE_INT"')
+      '"device=memory,mem=VALUE_MB[,slot=VALUE_MB],nslot=VALUE_INT[,canreboot=0|1]"')
 
   parser.add_argument('--socket', dest='unix_socket_location', required=True)
   parser.add_argument('remainding_argument_list', nargs=argparse.REMAINDER)
@@ -374,7 +374,7 @@ class QemuQMPWrapper(object):
       }
     })
 
-  def _updateMemory(self, mem_size, slot_size, slot_amount):
+  def _updateMemory(self, mem_size, slot_size, slot_amount, allow_reboot=False):
     """
       Update memory size according to the current value. option_dict contains:
 
@@ -423,8 +423,9 @@ class QemuQMPWrapper(object):
     if num_slot_used > 0 and slot_size != memory_id_list[0]['size']:
       # XXX - we won't change the defined size of RAM on slots on live,
       # restart qemu will allow to change the value
-      self.powerdown()
-      raise ValueError("The Size of RAM Slot changed. Rebooting...")
+      if allow_reboot:
+        self.powerdown()
+        raise ValueError("The Size of RAM Slot changed. Rebooting...")
 
     if (mem_size % slot_size) != 0:
       raise ValueError("Memory size %r is not a multiple of %r" % (mem_size,
@@ -441,6 +442,11 @@ class QemuQMPWrapper(object):
       raise ValueError("Memory size is not valid: %s" % option_dict)
     elif current_size > mem_size:
       # Request to remove memory
+      if allow_reboot:
+        # reboot so new memory size will be configured safely
+        self.powerdown()
+        raise ValueError("Rebooting because memory size was reduced...")
+
       slot_remove = (current_size - mem_size) / slot_size
       print "Removing %s memory slots of %s MB..." % (slot_remove, slot_size)
 
@@ -494,7 +500,8 @@ class QemuQMPWrapper(object):
         return self._updateMemory(
           mem_size=int(option_dict['mem']),
           slot_size=int(option_dict['slot']),
-          slot_amount=int(option_dict['nslot'])
+          slot_amount=int(option_dict['nslot']),
+          allow_reboot=int(option_dict.get('canreboot', 0)) in [1, True]
         )
       else:
         raise ValueError("Unknown device type: %s" % option_dict)

slapos/test/test_qemuqmpclient.py

@@ -502,5 +502,30 @@ class TestQemuQMPWrapper(unittest.TestCase):
     self.assertEquals(len(self.call_stack_list), 2)
     self.assertEquals(self.call_stack_list, expected_result)
 
+  def test_updateDevice_memory_will_reboot(self):
+    qmpwrapper = QemuQMPWrapper(self.socket_file, auto_connect=False)
+    qmpwrapper._send = self.fake_send
+    self.hotplugged_memory_amount = 3072
+    # slot of 1G
+    self.memory_slot_size = 1024
+    # decrease memory to 1G, expext remove slot 3 and 2.
+    cpu_option = {
+      'device': 'memory',
+      'nslot': 4,
+      'mem': 1024,
+      'slot': self.memory_slot_size,
+      'canreboot': True
+    }
+    with self.assertRaises(ValueError):
+      qmpwrapper.updateDevice(cpu_option)
+    expected_result = [
+      {'execute': 'query-memory-devices'},
+      {'execute': 'query-memdev'},
+      {'execute': 'system_powerdown'}
+    ]
+
+    self.assertEquals(len(self.call_stack_list), 3)
+    self.assertEquals(self.call_stack_list, expected_result)
+
 if __name__ == '__main__':
   unittest.main()