Below are the general guidelines on Hot Plug support in UltraScale/UltraScale+ PCI Express Integrated Block IPs.
As an endpoint, there are no special requirements a user needs to enable/configure to support Hot Plug.
Hot plug in Root Port configuration requires a hot plug controller on the board.
This is the users' responsibility to implement it and is not implemented in Xilinx IP.
Hot plug support requires user interaction with the following three registers.
The Slot Status Register and Slot Capabilities Register must be configured and updated by the user through the configuration management interface.
The user software needs to write to the Slot Control Register based on the user actions.
Slot Status Register
Slot Capabilities Register
Slot Control Register
To update the Slot Status Register, the user gets the required information from the Hot Plug Controller on the board and feeds it to the FPGA.
The user needs to take this information and use it to update the Slot Status Register through the configuration management interface.
It is the users' responsibility to update the Slot Capabilities Register through the configuration management interface.
This register cannot be configured in the core configuration GUI.
Please check the relevant section of the PCI Express Specification for the details on Hot Plug working mechanism.