Fix ordering of AdminVM and QubesVM

AdminVM instances must always compare less than any QubesVM instance.

Fixes: QubesOS/qubes-issues#6998
(cherry picked from commit 5078bd9)

qubes/tests/vm/adminvm.py

@@ -180,3 +180,6 @@ def test_710_run_service_for_stdio(self, mock_run_service):
             self.assertEqual(exc.exception.returncode, 1)
             self.assertEqual(exc.exception.output, b'stdout')
             self.assertEqual(exc.exception.stderr, b'stderr')
+
+    def test_711_adminvm_ordering(self):
+        assert(self.vm < qubes.vm.qubesvm.QubesVM(self.app, None, qid=1, name="dom0"))

qubes/tests/vm/qubesvm.py

@@ -2280,3 +2280,6 @@ def property_change(vm, property_name, new_value):
 
         property_change(test_vm, "template_for_dispvms", False)
         property_change(test_vm, "template_for_dispvms", True)
+
+    def test_801_ordering(self):
+        assert qubes.vm.qubesvm.QubesVM(self.app, None, qid=1, name="bogus") > qubes.vm.adminvm.AdminVM(self.app, None)

qubes/vm/adminvm.py

@@ -29,9 +29,10 @@
 import qubes.exc
 import qubes.vm
 from qubes.vm.qubesvm import _setter_kbd_layout
+from qubes.vm import BaseVM
 
 
-class AdminVM(qubes.vm.BaseVM):
+class AdminVM(BaseVM):
     '''Dom0'''
 
     dir_path = None
@@ -82,16 +83,21 @@ def __init__(self, *args, **kwargs):
     def __str__(self):
         return self.name
 
-    def __lt__(self, other):
+    def __lt__(self, other: object):
+        if not isinstance(other, BaseVM):
+            return NotImplemented
         # order dom0 before anything
-        return self.name != other.name
+        if not isinstance(other, AdminVM):
+            return True
+        assert self is other, "multiple instances of AdminVM?"
+        return False
 
     @property
     def attached_volumes(self):
         return []
 
     @property
-    def xid(self):
+    def xid(self) -> int:
         '''Always ``0``.
 
         .. seealso:

qubes/vm/qubesvm.py

@@ -40,6 +40,7 @@
 import qubes.storage
 import qubes.utils
 import qubes.vm
+import qubes.vm.adminvm
 import qubes.vm.mix.net
 
 qmemman_present = False
@@ -959,6 +960,10 @@ def __hash__(self):
         return self.qid
 
     def __lt__(self, other):
+        if not isinstance(other, qubes.vm.BaseVM):
+            return NotImplemented
+        if isinstance(other, qubes.vm.adminvm.AdminVM):
+            return False
         return self.name < other.name
 
     def __xml__(self):