1. A management CPU in a PCI Express (PCIe) network, comprising: a memory; a processor for managing initialization of a plurality of I/O devices coupled to a PCIe fabric of the management CPU, wherein the PCIe fabric includes a non-transparent bridge (NTB) through which the PCIe fabric is coupled to a worker CPU of the PCIe network; the processor being configured to perform operations of: receiving a request from the worker CPU to enable a first I/O device in the PCIe fabric of the management CPU to send a first interrupt to the worker CPU, wherein the worker CPU has assigned a target interrupt register address for receiving the first interrupt; mapping the target interrupt register address to a mapped interrupt register address for use by the first I/O device in the PCIe fabric of the management CPU to sent the first interrupt to the worker CPU through the NTB; and sending an instruction to the first I/O device to register the mapped interrupt register address for the first interrupt in a I/O interrupt vector table of the first I/O device.