Virtuozzo Virtualization SDK C API Reference
Determines whether the virtual machine requires a default device of the specified type if it's going to run an operating system of the specified type.
The function accepts the target operating system type, version, and a device type identifier. Using these parameters, it determines if the specified device is required in order for the projected virtual machine to run properly. If the device is required, you must add it to the virtual machine using the PrlVmCfg_AddDefaultDevice function. If the device is not required, you don't have to add it (i.e. it will not affect the operation of a virtual machine).