Daemon tools hangs updating virtual devices
Although this information can instead be learned by reverse engineering, this is much more difficult with hardware than it is with software.
These factors make it more difficult and dangerous to diagnose problems.
The virtual device driver can also send simulated processor-level events like interrupts into the virtual machine.
Virtual devices may also operate in a non-virtualized environment.
But in recent years non-vendors have written numerous device drivers, mainly for use with free and open source operating systems.
In such cases, it is important that the hardware manufacturer provides information on how the device communicates.