Option to ask for password when leaving virtual machine

[Jakob]

It would sometimes be quiet useful to have an option which makes VirtualBox ask for a password when leaving a virtual machine. This feature would make it possible to let someone else use the computer (e.g. for surfing the Internet or trying out another operating system) without giving that person access to the host operating system. This way you can be sure that the other person can't access your data or do any harm to the host system (even if you give him root access in the guest system). A feature like this might also be useful for an Internet café so that customers can get full access to a virtual machine and install software on it.

This feature could possibly be implemented based on the lock screen functionality of the host operating system. When the user enters the host key, he could be asked whether he really wants to leave the virtual machine. When the user confirms, VirtualBox should lock the screen so that entering the password is required for getting back to the host system.