drm/virtio: Add fences for Guest blobs

Add prepare and cleanup routines for primary planes as well
where a fence is added only if the BO/FB associated with the
plane is a guest blob.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20210610232456.671905-2-vivek.kasireddy@intel.comSigned-off-by: Gerd Hoffmann <kraxel@redhat.com>

drivers/gpu/drm/virtio/virtgpu_plane.c

@@ -206,8 +206,8 @@ static void virtio_gpu_primary_plane_update(struct drm_plane *plane,
 	virtio_gpu_notify(vgdev);
 }
 
-static int virtio_gpu_cursor_prepare_fb(struct drm_plane *plane,
-					struct drm_plane_state *new_state)
+static int virtio_gpu_plane_prepare_fb(struct drm_plane *plane,
+				       struct drm_plane_state *new_state)
 {
 	struct drm_device *dev = plane->dev;
 	struct virtio_gpu_device *vgdev = dev->dev_private;
@@ -219,7 +219,10 @@ static int virtio_gpu_cursor_prepare_fb(struct drm_plane *plane,
 
 	vgfb = to_virtio_gpu_framebuffer(new_state->fb);
 	bo = gem_to_virtio_gpu_obj(vgfb->base.obj[0]);
-	if (bo && bo->dumb && (plane->state->fb != new_state->fb)) {
+	if (!bo || (plane->type == DRM_PLANE_TYPE_PRIMARY && !bo->guest_blob))
+		return 0;
+
+	if (bo->dumb && (plane->state->fb != new_state->fb)) {
 		vgfb->fence = virtio_gpu_fence_alloc(vgdev);
 		if (!vgfb->fence)
 			return -ENOMEM;
@@ -228,8 +231,8 @@ static int virtio_gpu_cursor_prepare_fb(struct drm_plane *plane,
 	return 0;
 }
 
-static void virtio_gpu_cursor_cleanup_fb(struct drm_plane *plane,
-					 struct drm_plane_state *old_state)
+static void virtio_gpu_plane_cleanup_fb(struct drm_plane *plane,
+					struct drm_plane_state *old_state)
 {
 	struct virtio_gpu_framebuffer *vgfb;
 
@@ -321,13 +324,15 @@ static void virtio_gpu_cursor_plane_update(struct drm_plane *plane,
 }
 
 static const struct drm_plane_helper_funcs virtio_gpu_primary_helper_funcs = {
+	.prepare_fb		= virtio_gpu_plane_prepare_fb,
+	.cleanup_fb		= virtio_gpu_plane_cleanup_fb,
 	.atomic_check		= virtio_gpu_plane_atomic_check,
 	.atomic_update		= virtio_gpu_primary_plane_update,
 };
 
 static const struct drm_plane_helper_funcs virtio_gpu_cursor_helper_funcs = {
-	.prepare_fb		= virtio_gpu_cursor_prepare_fb,
-	.cleanup_fb		= virtio_gpu_cursor_cleanup_fb,
+	.prepare_fb		= virtio_gpu_plane_prepare_fb,
+	.cleanup_fb		= virtio_gpu_plane_cleanup_fb,
 	.atomic_check		= virtio_gpu_plane_atomic_check,
 	.atomic_update		= virtio_gpu_cursor_plane_update,
 };