Add support for saving VM state after test failure

client/bin/site_utils.py

 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import time
+import os, logging, platform, time

[petkov, 2010/11/24 20:36:53]

sort

[thieule, 2010/11/30 23:05:08]

Done.

 from autotest_lib.client.common_lib import error
 
 
 class TimeoutError(error.TestError):
     """Error raised when we time out when waiting on a condition."""
 
 
 def poll_for_condition(
     condition, exception=None, timeout=10, sleep_interval=0.1, desc=None):
     """Poll until a condition becomes true.
@@ skipping 15 matching lines @@
             if exception:
                 raise exception
 
             if desc:
                 desc = 'Timed out waiting for condition: %s' % desc
             else:
                 desc = 'Timed out waiting for unnamed condition'
             raise TimeoutError, desc
 
         time.sleep(sleep_interval)
+
+
+def save_vm_state(checkpoint):
+    """Saves the current state of the virtual machine

[petkov, 2010/11/24 20:36:53]

period

[thieule, 2010/11/30 23:05:08]

Done.

+
+    This function is a NOOP if the test is not running under a virtual machine
+    with the USB serial port redirected.
+
+    Arguments:
+      checkpoint - Name used to identify this state
+
+    Returns:
+      None
+    """
+    # The QEMU monitor has been redirected to the guest serial port located at
+    # /dev/ttyUSB0. To save the state of the VM, we just send the 'savevm'
+    # command to the serial port.
+    proc = platform.processor()
+    if proc.find('QEMU') >= 0 and os.path.exists('/dev/ttyUSB0'):

[petkov, 2010/11/24 20:36:53]

'QEMU' in proc?

[thieule, 2010/11/30 23:05:08]

I was a bit surprised myself as well to find python platform.processor()
returns:

'QEMU Virtual CPU version 0.12.3'

+        logging.info('Saving VM state "%s"' % checkpoint)
+        serial = open('/dev/ttyUSB0', 'w')
+        serial.write("savevm %s\r\n" % checkpoint)
+        logging.info('Done saving VM state "%s"' % checkpoint)