1. An apparatus for transferring data in a load/store fabric between a plurality of root complexes and a shared input/output (I/O) endpoint, the apparatus comprising: an interface configured to receive a packet, the packet including a header field for identifying the shared I/O endpoint; and circuitry configured to: add an operating system domain (OSD) header field to the packet for identifying which one of the plurality of root complexes is associated with the packet; and transfer the packet with the added OSD header field to the shared endpoint.