core: store dom0 info in qubes.xml

At least to have there info about its backup.

core-modules/006QubesDom0NetVm.py

@@ -26,6 +26,10 @@ from qubes.qubes import defaults
 from qubes.qubes import QubesException,dry_run
 
 class QubesDom0NetVm(QubesNetVm):
+
+    # In which order load this VM type from qubes.xml
+    load_order = 10
+
     def __init__(self, **kwargs):
         super(QubesDom0NetVm, self).__init__(qid=0, name="dom0", netid=0,
                                              dir_path=None,
@@ -35,6 +39,10 @@ class QubesDom0NetVm(QubesNetVm):
                                              **kwargs)
         self.xid = 0
 
+    @property
+    def type(self):
+        return "Dom0NetVM"
+
     def is_running(self):
         return True
 
@@ -83,9 +91,6 @@ class QubesDom0NetVm(QubesNetVm):
         domains = xc.domain_getinfo(0, 1)
         return domains[0]
 
-    def create_xml_element(self):
-        return None
-
     def verify_files(self):
         return True
 

core/qubes.py

@@ -609,10 +609,6 @@ class QubesVmCollection(dict):
     def load(self):
         self.clear()
 
-        dom0vm = QubesDom0NetVm (collection=self)
-        self[dom0vm.qid] = dom0vm
-        self.default_netvm_qid = 0
-
         try:
             tree = lxml.etree.parse(self.qubes_store_file)
         except (EnvironmentError,
@@ -661,6 +657,12 @@ class QubesVmCollection(dict):
         # using 123/udp port)
         if self.clockvm_qid is not None:
             self[self.clockvm_qid].services['ntpd'] = False
+
+        # Add dom0 if wasn't present in qubes.xml
+        if not 0 in self.keys():
+            dom0vm = QubesDom0NetVm (collection=self)
+            self[dom0vm.qid] = dom0vm
+
         return True
 
     def pop(self, qid):