drm/qxl: use suggested x/y offset properties to pass guest prefs

This passes the guest preferences for a where to place the
outputs through to userspace. Userspace would need to be updated
to take note of this information, X server and GNOME.
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/qxl/qxl_display.c

@@ -101,14 +101,37 @@ static int qxl_display_copy_rom_client_monitors_config(struct qxl_device *qdev)
 	return 0;
 }
 
+static void qxl_update_offset_props(struct qxl_device *qdev)
+{
+	struct drm_device *dev = qdev->ddev;
+	struct drm_connector *connector;
+	struct qxl_output *output;
+	struct qxl_head *head;
+
+	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+		output = drm_connector_to_qxl_output(connector);
+
+		head = &qdev->client_monitors_config->heads[output->index];
+
+		drm_object_property_set_value(&connector->base,
+			dev->mode_config.suggested_x_property, head->x);
+		drm_object_property_set_value(&connector->base,
+			dev->mode_config.suggested_y_property, head->y);
+	}
+}
+
 void qxl_display_read_client_monitors_config(struct qxl_device *qdev)
 {
 
+	struct drm_device *dev = qdev->ddev;
 	while (qxl_display_copy_rom_client_monitors_config(qdev)) {
 		qxl_io_log(qdev, "failed crc check for client_monitors_config,"
 				 " retrying\n");
 	}
 
+	drm_modeset_lock_all(dev);
+	qxl_update_offset_props(qdev);
+	drm_modeset_unlock_all(dev);
 	if (!drm_helper_hpd_irq_event(qdev->ddev)) {
 		/* notify that the monitor configuration changed, to
 		   adjust at the arbitrary resolution */
@@ -952,6 +975,10 @@ static int qdev_output_init(struct drm_device *dev, int num_output)
 
 	drm_object_attach_property(&connector->base,
 				   qdev->hotplug_mode_update_property, 0);
+	drm_object_attach_property(&connector->base,
+				   dev->mode_config.suggested_x_property, 0);
+	drm_object_attach_property(&connector->base,
+				   dev->mode_config.suggested_y_property, 0);
 	drm_connector_register(connector);
 	return 0;
 }
@@ -1065,6 +1092,7 @@ int qxl_modeset_init(struct qxl_device *qdev)
 
 	qdev->ddev->mode_config.fb_base = qdev->vram_base;
 
+	drm_mode_create_suggested_offset_properties(qdev->ddev);
 	qxl_mode_create_hotplug_mode_update_property(qdev);
 
 	for (i = 0 ; i < qxl_num_crtc; ++i) {