I am now using windbg for dual-machine debugging.
I loaded my own graphics driver kernel kernel.sys on the target machine, and then used the .load externel.dll command in windbg to load a dynamic link library.
In my driver code, I set a config structure containing the function pointer of the kernel function I want to call. In the dynamic library externel, use the getsymboltype and getfieldoffset
to get the function.