Compartmentalization is the technique of separating parts of a system to decrease attack surface and prevent malfunctions from cascading in the system. In Ghaf architecture, there is a separate VM for every vital function of the system.

Current implementation supports GUI VM, Networking VM and a couple of Application VMs, such as the Chromium web browser and the Zathura document viewer.

The GUI VM owns a computer's GPU and performs desktop environment and application windows rendering. Wayland protocol for applications in this case is proxified by waypipe over SSH. This approach is used temporarily before moving to more sophisticated solutions.

A VM compartmentalization requires all necessary devices passthrough in place. More specifically, you need to know the PCI VID and PID of a device and also its number on the PCI bus. In the case of a USB device passthrough, it is enough to know the device's VID and PID.

For more information on actual implementation, see Ghaf as Library and Creating Application VM.