Device drivers

Virtual device drivers

Virtual device drivers represent a particular variant of device drivers. They are used to emulate a hardware device, particularly in virtualization environments, for example, when a guest operating system is run on a Xen host. Instead of enabling the guest operating system to control the hardware, virtual device drivers emulate a piece of hardware, so that the guest operating system and its drivers running inside a virtual machine can have the illusion of accessing real hardware. Attempts by the guest operating system to access the hardware are routed to the virtual device driver in the host operating system. The virtual device driver can also send simulated hardware-related events like interrupts to the virtual machine.