xend: Make hotplug script timeouts configurable

In some configurations, when dom0 is busy with I/O, it may take
several minutes to complete all hotplug scripts required when a new
domain is being created. As device create timeout is set to 100
seconds, users get "hotplug scripts not working" error instead of a
new domain.

This patch makes both DEVICE_CREATE_TIMEOUT and DEVICE_DESTROY_TIMEOUT
configurable in xend-config.sxp to allow users to easily adapt hotplug
timeouts to their environment.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

tools/python/xen/xend/XendOptions.py

@@ -141,6 +141,12 @@ class XendOptions:
     """Default rotation count of qemu-dm log file."""
     qemu_dm_logrotate_count = 10
 
+    """Default timeout for device creation."""
+    device_create_timeout_default = 100
+
+    """Default timeout for device destruction."""
+    device_destroy_timeout_default = 100
+
     def __init__(self):
         self.configure()
 
@@ -368,6 +374,14 @@ class XendOptions:
         return self.get_config_int("qemu-dm-logrotate-count",
                                    self.qemu_dm_logrotate_count)
 
+    def get_device_create_timeout(self):
+        return self.get_config_int("device-create-timeout",
+                                   self.device_create_timeout_default)
+
+    def get_device_destroy_timeout(self):
+        return self.get_config_int("device-destroy-timeout",
+                                   self.device_destroy_timeout_default)
+
 
 class XendOptionsFile(XendOptions):
 

tools/python/xen/xend/server/DevConstants.py

@@ -16,8 +16,12 @@
 # Copyright (C) 2005 XenSource Ltd
 #============================================================================
 
-DEVICE_CREATE_TIMEOUT  = 100
-DEVICE_DESTROY_TIMEOUT = 100
+from xen.xend import XendOptions
+
+xoptions = XendOptions.instance()
+
+DEVICE_CREATE_TIMEOUT  = xoptions.get_device_create_timeout();
+DEVICE_DESTROY_TIMEOUT = xoptions.get_device_destroy_timeout();
 HOTPLUG_STATUS_NODE = "hotplug-status"
 HOTPLUG_ERROR_NODE  = "hotplug-error"
 HOTPLUG_STATUS_ERROR = "error"