PCI Express Hot Plug is derived from the 1.0 revision of the Standard Hot Plug Controller specification (SHPC 1.0) for PCI. The goals of PCI Express Hot Plug are to:
support the same “Standardized Usage Model” as defined by the Standard Hot Plug Controller specification. This ensures that the PCI Express hot plug is identical from the user perspective to existing implementations based on the SHPC 1.0 specification
support the same software model implemented by existing operating systems. However, if the OS includes a SHPC 1.0 compliant driver, it will not work with PCI Express Hot Plug controllers, which have a different programming interface.
PCI Express defines the registers necessary to support the integration ...