I am looking at using Qemu (specifically the x86_64 pc emulation) as a testbed for a new PCI widget. I have begun looking through the code for the e1000 nic as it seems to be frequently used and is therefore likely quite robust. Is there a better place for me to start looking? In particular, is there any API documentation for the PCIDevice structure and the various memory hooks? I have started hacking a new module based on what I can see in the code and using a debugger, but I suspect that it will be a long steep learning curve that way!
Lacking API docs, has anyone out there who is familiar with the pci subsystem ever scribbled down a crib sheet for what needs to be included to model a new device? I am comfortable with pretty high level bullet points describing the main steps in the initializing the structure so it can be seen by the kernel driver and interact correctly with the memory subsystem.