A system includes a virtualized I/O device coupled to one or more processing units. The virtualized I/O device includes a storage for storing a resource discovery table, and programmed I/O (PIO) configuration registers corresponding to hardware resources. A system processor may allocate the plurality of hardware resources to one or more functions, and to populate each entry of the resource discovery table for each function. The processing units may execute one or more processes. Given processing units may further execute OS instructions to allocate space for an I/O mapping of a PIO configuration space in a system memory, and to assign a function to a respective process. Processing units may execute a device driver instance associated with a given process to discover allocated resources by requesting access to the resource discovery table. The virtualized I/O device protects the resources by checking access requests against the resource discovery table.