api/admin: implement admin.vm.device....Set.persistent

This will allow converting persistent device (used to boot VM for
example) to non-persistent.

QubesOS/qubes-issues#3055

Makefile

@@ -55,14 +55,17 @@ ADMIN_API_METHODS_SIMPLE = \
 	admin.vm.device.pci.Available \
 	admin.vm.device.pci.Detach \
 	admin.vm.device.pci.List \
+	admin.vm.device.pci.Set.persistent \
 	admin.vm.device.block.Attach \
 	admin.vm.device.block.Available \
 	admin.vm.device.block.Detach \
 	admin.vm.device.block.List \
+	admin.vm.device.block.Set.persistent \
 	admin.vm.device.mic.Attach \
 	admin.vm.device.mic.Available \
 	admin.vm.device.mic.Detach \
 	admin.vm.device.mic.List \
+	admin.vm.device.mic.Set.persistent \
 	admin.vm.feature.CheckWithTemplate \
 	admin.vm.feature.Get \
 	admin.vm.feature.List \
@@ -188,6 +191,7 @@ endif
 		          admin.vm.device.testclass.Attach \
 				  admin.vm.device.testclass.Detach \
 				  admin.vm.device.testclass.List \
+				  admin.vm.device.testclass.Set.persistent \
 				  admin.vm.device.testclass.Available
 	# sanity check
 	for method in $(DESTDIR)/etc/qubes-rpc/policy/admin.*; do \

qubes/api/admin.py

@@ -1093,6 +1093,36 @@ class QubesAdminAPI(qubes.api.AbstractQubesAPI):
         yield from self.dest.devices[devclass].detach(assignment)
         self.app.save()
 
+    # Attach/Detach action can both modify persistent state (with
+    # persistent=True) and volatile state of running VM (with persistent=False).
+    # For this reason, write=True + execute=True
+    @qubes.api.method('admin.vm.device.{endpoint}.Set.persistent',
+        endpoints=(ep.name
+            for ep in pkg_resources.iter_entry_points('qubes.devices')),
+        scope='local', write=True, execute=True)
+    @asyncio.coroutine
+    def vm_device_set_persistent(self, endpoint, untrusted_payload):
+        devclass = endpoint
+
+        assert untrusted_payload in (b'True', b'False')
+        persistent = untrusted_payload == b'True'
+        del untrusted_payload
+
+        # qrexec already verified that no strange characters are in self.arg
+        backend_domain, ident = self.arg.split('+', 1)
+        # device must be already attached
+        matching_devices = [dev for dev
+            in self.dest.devices[devclass].attached()
+            if dev.backend_domain.name == backend_domain and dev.ident == ident]
+        assert len(matching_devices) == 1
+        dev = matching_devices[0]
+
+        self.fire_event_for_permission(device=dev,
+            persistent=persistent)
+
+        self.dest.devices[devclass].update_persistent(dev, persistent)
+        self.app.save()
+
     @qubes.api.method('admin.vm.firewall.Get', no_payload=True,
             scope='local', read=True)
     @asyncio.coroutine

qubes/tests/api_admin.py

@@ -2131,6 +2131,102 @@ class TC_00_VMs(AdminAPITestCase):
                 b'test-vm1')
         self.assertFalse(self.app.save.called)
 
+    def test_650_vm_device_set_persistent_true(self):
+        self.vm.add_handler('device-list:testclass',
+            self.device_list_testclass)
+        self.vm.add_handler('device-list-attached:testclass',
+            self.device_list_attached_testclass)
+        with unittest.mock.patch.object(qubes.vm.qubesvm.QubesVM,
+                'is_halted', lambda _: False):
+            value = self.call_mgmt_func(
+                b'admin.vm.device.testclass.Set.persistent',
+                b'test-vm1', b'test-vm1+1234', b'True')
+        self.assertIsNone(value)
+        dev = qubes.devices.DeviceInfo(self.vm, '1234')
+        self.assertIn(dev, self.vm.devices['testclass'].persistent())
+        self.app.save.assert_called_once_with()
+
+    def test_651_vm_device_set_persistent_false_unchanged(self):
+        self.vm.add_handler('device-list:testclass',
+            self.device_list_testclass)
+        self.vm.add_handler('device-list-attached:testclass',
+            self.device_list_attached_testclass)
+        with unittest.mock.patch.object(qubes.vm.qubesvm.QubesVM,
+                'is_halted', lambda _: False):
+            value = self.call_mgmt_func(
+                b'admin.vm.device.testclass.Set.persistent',
+                b'test-vm1', b'test-vm1+1234', b'False')
+        self.assertIsNone(value)
+        dev = qubes.devices.DeviceInfo(self.vm, '1234')
+        self.assertNotIn(dev, self.vm.devices['testclass'].persistent())
+        self.app.save.assert_called_once_with()
+
+    def test_652_vm_device_set_persistent_false(self):
+        self.vm.add_handler('device-list:testclass',
+            self.device_list_testclass)
+        assignment = qubes.devices.DeviceAssignment(self.vm, '1234', {},
+            True)
+        self.loop.run_until_complete(
+            self.vm.devices['testclass'].attach(assignment))
+        self.vm.add_handler('device-list-attached:testclass',
+            self.device_list_attached_testclass)
+        dev = qubes.devices.DeviceInfo(self.vm, '1234')
+        self.assertIn(dev, self.vm.devices['testclass'].persistent())
+        with unittest.mock.patch.object(qubes.vm.qubesvm.QubesVM,
+                'is_halted', lambda _: False):
+            value = self.call_mgmt_func(
+                b'admin.vm.device.testclass.Set.persistent',
+                b'test-vm1', b'test-vm1+1234', b'False')
+        self.assertIsNone(value)
+        self.assertNotIn(dev, self.vm.devices['testclass'].persistent())
+        self.assertIn(dev, self.vm.devices['testclass'].attached())
+        self.app.save.assert_called_once_with()
+
+    def test_653_vm_device_set_persistent_true_unchanged(self):
+        self.vm.add_handler('device-list:testclass',
+            self.device_list_testclass)
+        assignment = qubes.devices.DeviceAssignment(self.vm, '1234', {},
+            True)
+        self.loop.run_until_complete(
+            self.vm.devices['testclass'].attach(assignment))
+        self.vm.add_handler('device-list-attached:testclass',
+            self.device_list_attached_testclass)
+        with unittest.mock.patch.object(qubes.vm.qubesvm.QubesVM,
+                'is_halted', lambda _: False):
+            value = self.call_mgmt_func(
+                b'admin.vm.device.testclass.Set.persistent',
+                b'test-vm1', b'test-vm1+1234', b'True')
+        self.assertIsNone(value)
+        dev = qubes.devices.DeviceInfo(self.vm, '1234')
+        self.assertIn(dev, self.vm.devices['testclass'].persistent())
+        self.assertIn(dev, self.vm.devices['testclass'].attached())
+        self.app.save.assert_called_once_with()
+
+    def test_654_vm_device_set_persistent_not_attached(self):
+        self.vm.add_handler('device-list:testclass',
+            self.device_list_testclass)
+        with unittest.mock.patch.object(qubes.vm.qubesvm.QubesVM,
+                'is_halted', lambda _: False):
+            with self.assertRaises(AssertionError):
+                self.call_mgmt_func(
+                    b'admin.vm.device.testclass.Set.persistent',
+                    b'test-vm1', b'test-vm1+1234', b'True')
+        dev = qubes.devices.DeviceInfo(self.vm, '1234')
+        self.assertNotIn(dev, self.vm.devices['testclass'].persistent())
+        self.assertFalse(self.app.save.called)
+
+    def test_655_vm_device_set_persistent_invalid_value(self):
+        self.vm.add_handler('device-list:testclass',
+            self.device_list_testclass)
+        with unittest.mock.patch.object(qubes.vm.qubesvm.QubesVM,
+                'is_halted', lambda _: False):
+            with self.assertRaises(AssertionError):
+                self.call_mgmt_func(
+                    b'admin.vm.device.testclass.Set.persistent',
+                    b'test-vm1', b'test-vm1+1234', b'maybe')
+        dev = qubes.devices.DeviceInfo(self.vm, '1234')
+        self.assertNotIn(dev, self.vm.devices['testclass'].persistent())
+        self.assertFalse(self.app.save.called)
 
     def test_990_vm_unexpected_payload(self):
         methods_with_no_payload = [