I found this post:
nvidia-smi command not found Ubuntu 16.04 | Ask Ubuntu
Which says that with IUEF secure boot enabled nvidia-smi could not found in ubuntu:
$ nvidia-smi nvidia-smi: command not found
Any idea on how to enable secure boot with nvidai driver funcioning?
I found this article on solving the secure boot issue with virtual box, just still have little idea on how MOK manager works: