Patent attributes
A method for extending a Peripheral Component Interconnect Express (PCIe) domain. A configuration space address can be allocated to a PCIe device in an extended domain from a memory address of a root complex endpoint device, a correspondence between the configuration space address and a bus number/device number/function number (BDF) can be established, and a bus number can be allocated from a second bus set of the extended domain to a PCIe device discovered in the extended domain, where the bus number is used for determining the BDF of the PCIe device discovered in the extended domain, so as to access, according to the correspondence between the configuration space address and the BDF and by using the BDF of the PCIe device discovered in the extended domain, a configuration space register of the PCIe device discovered in the extended domain.