drm/virtio: implement blob resources: blob display integration

SCANOUT_BLOB forwards the DRM framebuffer metadata to the host. The
modifier is intentionally left out -- it may be possible to query
the host for that.

We also assume one blob resource per DRM framebuffer.  That too is
an intentional simplification.
Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org>
Acked-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20200924003214.662-14-gurchetansingh@chromium.orgSigned-off-by: Gerd Hoffmann <kraxel@redhat.com>

drivers/gpu/drm/virtio/virtgpu_plane.c

@@ -174,6 +174,16 @@ static void virtio_gpu_primary_plane_update(struct drm_plane *plane,
 			  plane->state->src_h >> 16,
 			  plane->state->src_x >> 16,
 			  plane->state->src_y >> 16);
+
+		if (bo->host3d_blob || bo->guest_blob) {
+			virtio_gpu_cmd_set_scanout_blob
+						(vgdev, output->index, bo,
+						 plane->state->fb,
+						 plane->state->src_w >> 16,
+						 plane->state->src_h >> 16,
+						 plane->state->src_x >> 16,
+						 plane->state->src_y >> 16);
+		} else {
 			virtio_gpu_cmd_set_scanout(vgdev, output->index,
 						   bo->hw_res_handle,
 						   plane->state->src_w >> 16,
@@ -181,6 +191,7 @@ static void virtio_gpu_primary_plane_update(struct drm_plane *plane,
 						   plane->state->src_x >> 16,
 						   plane->state->src_y >> 16);
 		}
+	}
 
 	virtio_gpu_cmd_resource_flush(vgdev, bo->hw_res_handle,
 				      rect.x1,