The DFX Controller does not (yet) know about Nested Dynamic Function eXchange, but it can still be used in this environment. Additional circuitry is needed to safeguard against loading partial bitstreams that would be incompatible with the currently operating design.
In the example design, a DFX Controller IP could be created to manage partial bitstreams for the entire design. It must be customized to understand five RPs: A, W, X, Y, and Z.
However, it does not know about the dependencies they have on each other, so the designer must build this part of the solution external to the IP.
For example, if RM A1 is currently loaded, the designer must not allow any trigger events that would reconfigure RPs Y or Z, only W or X. Each RP (Virtual Socket) has its own request, acknowledge and decouple controls, and these can be sent into a parent RP to access user logic that can manage child RPs - only acknowledge a request for reconfiguration if the target RP currently exists. Alternately, an AXI4-Lite interface can be used to read the current status of a parent RP managed by the DFX Controller to understand what child RPs can be reconfigured.