drm/virtio: add virtio-gpu-features debugfs file.

This file prints which features the virtio-gpu device has.

Also add "virtio-gpu-" prefix to the existing fence file,
to make clear this is a driver-specific debugfs file.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Noralf Trønnes <noralf@tronnes.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20190320083612.32067-1-kraxel@redhat.com

drivers/gpu/drm/virtio/virtgpu_debugfs.c

@@ -28,6 +28,30 @@
 
 #include "virtgpu_drv.h"
 
+static void virtio_add_bool(struct seq_file *m, const char *name,
+				    bool value)
+{
+	seq_printf(m, "%-16s : %s\n", name, value ? "yes" : "no");
+}
+
+static void virtio_add_int(struct seq_file *m, const char *name,
+				   int value)
+{
+	seq_printf(m, "%-16s : %d\n", name, value);
+}
+
+static int virtio_gpu_features(struct seq_file *m, void *data)
+{
+	struct drm_info_node *node = (struct drm_info_node *) m->private;
+	struct virtio_gpu_device *vgdev = node->minor->dev->dev_private;
+
+	virtio_add_bool(m, "virgl", vgdev->has_virgl_3d);
+	virtio_add_bool(m, "edid", vgdev->has_edid);
+	virtio_add_int(m, "cap sets", vgdev->num_capsets);
+	virtio_add_int(m, "scanouts", vgdev->num_scanouts);
+	return 0;
+}
+
 static int
 virtio_gpu_debugfs_irq_info(struct seq_file *m, void *data)
 {
@@ -41,7 +65,8 @@ virtio_gpu_debugfs_irq_info(struct seq_file *m, void *data)
 }
 
 static struct drm_info_list virtio_gpu_debugfs_list[] = {
-	{ "irq_fence", virtio_gpu_debugfs_irq_info, 0, NULL },
+	{ "virtio-gpu-features", virtio_gpu_features },
+	{ "virtio-gpu-irq-fence", virtio_gpu_debugfs_irq_info, 0, NULL },
 };
 
 #define VIRTIO_GPU_DEBUGFS_ENTRIES ARRAY_SIZE(virtio_gpu_debugfs_list)