tests/kms: Ignore real GPUs when only VKMS is wanted

This prevents spurious test failures on machines with a real GPU as
well as VKMS.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/4274>

src/backends/meta-udev.h

@@ -42,6 +42,7 @@ gboolean meta_is_udev_device_disable_vrr (GUdevDevice *device);
 
 gboolean meta_is_udev_device_ignore (GUdevDevice *device);
 
+META_EXPORT_TEST
 gboolean meta_is_udev_test_device (GUdevDevice *device);
 
 gboolean meta_is_udev_device_preferred_primary (GUdevDevice *device);

src/tests/meson.build

@@ -653,7 +653,11 @@ kms_test_cases = [
   {
     'name': 'kms-headless-start',
     'suite': 'backend/native/kms',
-    'sources': [ 'native-kms-headless-start.c', ],
+    'sources': [
+      'meta-kms-test-utils.c',
+      'meta-kms-test-utils.h',
+      'native-kms-headless-start.c',
+    ],
   },
   {
     'name': 'kms-hotplug',

src/tests/meta-kms-test-utils.c

@@ -165,3 +165,28 @@ meta_get_mode_rect (MetaKmsMode *mode)
                              meta_kms_mode_get_width (mode),
                              meta_kms_mode_get_height (mode));
 }
+
+GUdevDevice *
+meta_get_test_udev_device (MetaUdev *udev)
+{
+  g_autolist (GObject) list = NULL;
+  g_autoptr (GError) error = NULL;
+  GUdevDevice *test_device = NULL;
+  GList *l;
+
+  list = meta_udev_list_drm_devices (udev, META_UDEV_DEVICE_TYPE_CARD, &error);
+
+  for (l = list; l; l = l->next)
+    {
+      GUdevDevice *udev_device = l->data;
+
+      if (meta_is_udev_test_device (udev_device))
+        {
+          g_assert_null (test_device);
+          g_set_object (&test_device, udev_device);
+        }
+    }
+
+  g_assert_nonnull (test_device);
+  return test_device;
+}

src/tests/meta-kms-test-utils.h

@@ -18,6 +18,7 @@
 
 #pragma once
 
+#include "backends/meta-udev.h"
 #include "backends/native/meta-drm-buffer.h"
 #include "backends/native/meta-kms-types.h"
 #include "meta/meta-context.h"
@@ -45,3 +46,5 @@ MetaDrmBuffer * meta_create_test_mode_dumb_buffer (MetaKmsDevice *device,
 MetaFixed16Rectangle meta_get_mode_fixed_rect_16 (MetaKmsMode *mode);
 
 MtkRectangle meta_get_mode_rect (MetaKmsMode *mode);
+
+GUdevDevice * meta_get_test_udev_device (MetaUdev *udev);

src/tests/native-kms-headless-start.c

@@ -26,6 +26,7 @@
 #include "core/display-private.h"
 #include "meta-test/meta-context-test.h"
 #include "tests/drm-mock/drm-mock.h"
+#include "tests/meta-kms-test-utils.h"
 #include "tests/meta-monitor-manager-test.h"
 
 static MetaContext *test_context;
@@ -75,20 +76,16 @@ meta_test_headless_monitor_connect (void)
   MetaUdev *udev = meta_backend_get_udev (backend);
   MetaMonitorManager *monitor_manager =
     meta_backend_get_monitor_manager (backend);
-  g_autolist (GObject) udev_devices = NULL;
+  g_autoptr (GUdevDevice) udev_device = NULL;
   GList *logical_monitors;
   MetaLogicalMonitor *logical_monitor;
   MtkRectangle monitor_layout;
   ClutterActor *stage;
-  g_autoptr (GError) error = NULL;
 
   drm_mock_unset_resource_filter (DRM_MOCK_CALL_FILTER_GET_CONNECTOR);
 
-  udev_devices = meta_udev_list_drm_devices (udev,
+  udev_device = meta_get_test_udev_device (udev);
-                                             META_UDEV_DEVICE_TYPE_CARD,
+  g_signal_emit_by_name (udev, "hotplug", udev_device);
-                                             &error);
-  g_assert_cmpuint (g_list_length (udev_devices), ==, 1);
-  g_signal_emit_by_name (udev, "hotplug", g_list_first (udev_devices)->data);
 
   logical_monitors =
     meta_monitor_manager_get_logical_monitors (monitor_manager);

src/tests/native-kms-hotplug.c

@@ -27,6 +27,7 @@
 #include "meta-test/meta-context-test.h"
 #include "tests/drm-mock/drm-mock.h"
 #include "tests/meta-test-utils.h"
+#include "tests/meta-kms-test-utils.h"
 
 typedef enum _State
 {
@@ -137,21 +138,15 @@ meta_test_disconnect_connect (void)
     meta_backend_get_monitor_manager (backend);
   ClutterActor *stage = meta_backend_get_stage (backend);
   MetaUdev *udev = meta_backend_get_udev (backend);
-  g_autolist (GObject) udev_devices = NULL;
+  g_autoptr (GUdevDevice) udev_device = NULL;
-  GUdevDevice *udev_device;
   GList *logical_monitors;
   gulong after_paint_handler_id;
   gulong presented_handler_id;
   ClutterStageView *view;
   CoglFramebuffer *onscreen;
-  g_autoptr (GError) error = NULL;
   State state;
 
-  udev_devices = meta_udev_list_drm_devices (udev,
+  udev_device = meta_get_test_udev_device (udev);
-                                             META_UDEV_DEVICE_TYPE_CARD,
-                                             &error);
-  g_assert_cmpuint (g_list_length (udev_devices), ==, 1);
-  udev_device = g_list_first (udev_devices)->data;
 
   logical_monitors =
     meta_monitor_manager_get_logical_monitors (monitor_manager);
@@ -372,15 +367,9 @@ emulate_hotplug (void)
 {
   MetaBackend *backend = meta_context_get_backend (test_context);
   MetaUdev *udev = meta_backend_get_udev (backend);
-  g_autoptr (GError) error = NULL;
+  g_autoptr (GUdevDevice) udev_device = NULL;
-  g_autolist (GObject) udev_devices = NULL;
-  GUdevDevice *udev_device;
 
-  udev_devices = meta_udev_list_drm_devices (udev,
+  udev_device = meta_get_test_udev_device (udev);
-                                             META_UDEV_DEVICE_TYPE_CARD,
-                                             &error);
-  g_assert_cmpuint (g_list_length (udev_devices), ==, 1);
-  udev_device = g_list_first (udev_devices)->data;
   g_signal_emit_by_name (udev, "hotplug", udev_device);
 }