An apparatus and method are provided that enable I/O devices to be shared among multiple operating system domains. The apparatus has a first plurality of I/O ports, a second I/O port, and link training logic. The first plurality of I/O ports is coupled to a plurality of operating system domains through a load-store fabric. Each of the first plurality of I/O ports is configured to route transactions between the plurality of operating system domains and the switching apparatus. The second I/O port is coupled to a first shared input/output endpoint. The first shared input/output endpoint is configured to request/complete the transactions for each of the plurality of operating system domains. The link training logic is coupled to the second I/O port. The link training logic initializes a link between the second I/O port and the first shared input/output endpoint to support the transactions corresponding to the each of the plurality of operating system domains. The link is initialized in a manner that is transparent to the plurality of operating system domains.