What host directories get mounted with --runtime nvidia?

I ran an nvidia docker container on my Jetson Nano following this hello world example: https://github.com/NVIDIA/nvidia-docker/wiki/NVIDIA-Container-Runtime-on-Jetson#hello-world

sudo docker run --runtime nvidia --network host -it -e DISPLAY=$DISPLAY -v /tmp/.X11-unix/:/tmp/.X11-unix nvcr.io/nvidia/l4t-base:r32.2

I was surprised to see that inside the container, my /usr/local/cuda directory was the same /usr/local/cuda directory as my host. How did that happen? I didn’t explicitly map that directory into the container.

It seems to be caused by specifying --runtime nvidia. What other surprises await me when I do --runtime nvidia (in terms of directories from the host that are mapped through to the container)? What other directories are mounted? Is this documented somewhere?

I also did a docker inspect to see binds or volumes, but the only thing I noticed is the binding of the /tmp/.X11-unix folder for the X socket. (Perhaps I’m overlooking something.)

Nvidia container runtime mounts several files and directories automatically. See this for details: https://github.com/NVIDIA/libnvidia-container/blob/jetson/design/mount_plugins.md