1. A method of controlling I/O operations of an I/O device by an application program comprising: creating a virtual connection within a system area network between the application program and the I/O device, the application program and the I/O device being coupled to the system area network; registering the application program's memory with the system area network; sending, by the application program, a request message for I/O service directly to the I/O device over the virtual connection, the request message including a virtual address of the application program's memory; and transferring I/O data between the I/O device and the application program's memory specified by the virtual address over the virtual connection.