Registering memory space within a data processing system is performed. One or more open calls are received from an application to access one or more input/output (I/O) devices. Responsive to receiving the one or more open calls, one or more I/O map and pin calls are sent in order to register memory space for the one or more I/O devices within at least one storage area that will be accessed by the application. At least one virtual I/O bus address is received for each registered memory space of the one or more I/O devices. At least one I/O command is executed using the at least one virtual I/O bus address without intervention by an operating system or operating system image.