1. A method, in a data processing system, for managing input/output (I/O) virtualization, comprising: creating one or more client partitions in the data processing system, each client partition having an associated portion of resources of the data processing system; performing I/O virtualization management operations with one or more I/O endpoints associated with the data processing system, wherein the I/O virtualization management operations operate to configure at least one of a physical function or a virtual function of the one or more I/O endpoints; and controlling access of the I/O virtualization management operations to resources of the one or more I/O endpoints using a virtual intermediary separate from the I/O virtualization management partition (IMP), wherein the virtual intermediary prevents a client partition from accessing resources of the one or more I/O endpoints that are not assigned to that client partition.