Exclude volatile DispVMs from Global Config

Excluding volatile DispVMs (disp*) while preserving named DispVMs
(e.g. sys-usb & sys-firewall) where it is relevant specifically:

1. From General tab -> Clock qube ComboBox
2. From Updates tab -> dom0 update proxy ComboBox
3. While Saving settings (since volatile disposables have no prefs for saving)
4. From Whonix update proxy options
5. From USB Devices tab (as safety measure)

related: QubesOS/qubes-issues#9924

Author: alimirjamali

qubes_config/global_config/global_config.py

@@ -690,11 +690,47 @@ def _ask_to_quit(self, *_args):
         return False
 
 
+class VMCollection(qubesadmin.app.VMCollection):
+    """
+    Overloaded class to get rid of volatile disposables
+    """
+
+    def __iter__(self):
+        for vm in super().__iter__():
+            try:
+                if vm.klass == "DispVM" and vm.auto_cleanup:
+                    continue
+            except:  # pylint: disable=bare-except
+                continue
+            yield vm
+
+
+class Qubes(qubesadmin.Qubes):
+    """
+    Overloaded class to get rid of volatile disposables
+    """
+
+    # Auxiliary domains collection which excludes true disposables (not named)
+    _domains = None
+
+    def __init__(self):
+        super().__init__()
+        self._domains = VMCollection(self)
+
+    @property
+    def domains(self):
+        return self._domains
+
+    @domains.setter
+    def domains(self, d):
+        self._domains = d
+
+
 def main():
     """
     Start the app
     """
-    qapp = qubesadmin.Qubes()
+    qapp = Qubes()
     qapp.cache_enabled = True
     policy_manager = PolicyManager()
     app = GlobalConfig(qapp, policy_manager)

qubes_config/tests/conftest.py

@@ -81,6 +81,7 @@
     "management_dispvm": ("vm", True, "default-mgmt-dvm"),
     "netvm": ("vm", False, "sys-firewall"),
     "template": ("vm", False, "fedora-36"),
+    "auto_cleanup": ("bool", True, "False"),
 }
 
 possible_tags = ["whonix-updatevm", "anon-gateway"]
@@ -345,6 +346,25 @@ def test_qapp_impl():
         [],
     )
 
+    add_expected_vm(
+        qapp,
+        "disp123",
+        "DispVM",
+        {"auto_cleanup": ("bool", False, "True")},
+        {"service.qubes-update-check": None},
+        [],
+    )
+
+    # This DispVM will die suddently in the middle of Global Config running
+    add_expected_vm(
+        qapp,
+        "disp666",
+        "DispVM",
+        {},
+        {"service.qubes-update-check": None},
+        [],
+    )
+
     add_expected_vm(
         qapp, "test-vm", "AppVM", {}, {"service.qubes-update-check": None}, []
     )

qubes_config/tests/test_global_config.py

@@ -29,8 +29,11 @@
     GlobalConfig,
     ClipboardHandler,
     FileAccessHandler,
+    VMCollection,
+    Qubes,
 )
 from ..global_config.basics_handler import BasicSettingsHandler
+from qubesadmin.tests import TestVMCollection, QubesTest
 
 import gi
 
@@ -49,6 +52,24 @@
 )
 
 
+@patch("qubesadmin.app.VMCollection", TestVMCollection)
+def test_vmcollection_global_config(test_qapp):
+    collection = VMCollection(test_qapp)
+    test_qapp.expected_calls[
+        ("disp666", "admin.vm.property.Get", "auto_cleanup", None)
+    ] = b"2\x00QubesNoSuchPropertyError\x00\x00DispVM suddenly died!\x00"
+    for vm in collection:
+        assert vm.name != "disp123"
+        assert vm.name != "disp666"
+
+
+@patch("qubesadmin.Qubes", QubesTest)
+def test_qubes_global_config():
+    app = Qubes()
+    app.domains = {}
+    assert app.domains == {}
+
+
 @patch("subprocess.check_output")
 @patch("qubes_config.global_config.global_config.show_error")
 def test_global_config_init(