Single Avalon-MM Master to Muliple Avalon-MM Slaves

I'm trying to connect multiple Avalon-MM slaves to a single Avalon-MM Master. I realize this essentially automatic using Qsys, if you're IP is defined as modules in Qsys. But all of my IP is already defined in VHDL and because of my build process, I can't (easily) create wrappers to import them into Qsys. I thought I could get Qsys to create a custom Ip (.qsys) module, but I can't figure out how to export Avalon-MM ports without attached IP. I'd happy to use a freestanding solution, if that were available. Any suggestions would be appreciated.