drm: virtio-gpu: ensure plane is flushed to host on atomic update

This fixes drawing updates when updating planes with atomic API.
Signed-off-by: NRob Herring <robh@kernel.org>
Signed-off-by: NDave Airlie <airlied@redhat.com>

drivers/gpu/drm/virtio/virtgpu_plane.c

@@ -84,6 +84,11 @@ static void virtio_gpu_plane_atomic_update(struct drm_plane *plane,
 				   plane->state->crtc_h,
 				   plane->state->crtc_x,
 				   plane->state->crtc_y);
+	virtio_gpu_cmd_resource_flush(vgdev, handle,
+				      plane->state->crtc_x,
+				      plane->state->crtc_y,
+				      plane->state->crtc_w,
+				      plane->state->crtc_h);
 }