My goal is to be protected against key disclosure laws and possible extortion. I know dm-crypt can be used to perform full disk encryption for GNU/Linux distros. However, it is not enough. I want to be able to hide an operating system in an encrypted hidden partition and create a decoy system for plausible deniability (à la Veracrypt and TrueCrypt). Furthermore, I cannot use Veracrypt or TrueCrypt as they do not support Operating System Encryption for anything other than Windows. Is there such a tool for GNU/Linux distros. In reality, I mainly use QubesOS, therefore I'm asking this question for both GNU/Linux distros and QubesOS.