Lock qemu vm during start / stop operations

Fix #301

gns3server/modules/qemu/qemu_vm.py

@@ -71,6 +71,7 @@ class QemuVM(BaseVM):
         self._cpulimit_process = None
         self._monitor = None
         self._stdout_file = ""
+        self._execute_lock = asyncio.Lock()
 
         # QEMU VM settings
         if qemu_path:
@@ -818,6 +819,7 @@ class QemuVM(BaseVM):
         Starts this QEMU VM.
         """
 
+        with (yield from self._execute_lock):
             if self.is_running():
                 # resume the VM if it is paused
                 yield from self.resume()
@@ -888,6 +890,7 @@ class QemuVM(BaseVM):
         Stops this QEMU VM.
         """
 
+        with (yield from self._execute_lock):
             # stop the QEMU process
             self._hw_virtualization = False
             if self.is_running():

gns3server/web/route.py

@@ -104,6 +104,8 @@ class Route(object):
             if request.headers["AUTHORIZATION"] == aiohttp.helpers.BasicAuth(user, password).encode():
                 return
 
+        log.error("Invalid auth. Username should %s", user)
+
         response = Response(request=request, route=route)
         response.set_status(401)
         response.headers["WWW-Authenticate"] = 'Basic realm="GNS3 server"'