On Sat, Aug 25, 2012 at 6:06 PM, Dominik Żeromski <dzero...@gmail.com> wrote: > 2012/8/25 Stefan Hajnoczi <stefa...@gmail.com> >> >> On Sat, Aug 25, 2012 at 12:10 PM, Dominik Żeromski <dzero...@gmail.com> >> wrote: >> > Adding support for loading DSO with -device option. >> > >> > Example Makefile for out of tree modules: >> >> QEMU does not have a stable ABI for devices. There is a lot of device >> model refactoring happening right now for multithreaded MMIO/PIO >> dispatch and taking advantage of QEMU Object Model. A stable ABI >> hinders those kinds of improvements. >> >> Send device model patches upstream. That way you avoid the >> maintenance overhead of out-of-tree modules and the QEMU community >> doesn't need to provide a stable ABI. >> > > I think that QEMU is a great tool, not only for server virtualization > but also for embedded software and hardware development. > > I agree that it would be hard to maintain stable ABI, but this is a > usability feature for device developers, not QEMU developers. I can > imagine use cases where one team works on a hardware emulator and > wants to share it with driver team. Driver team doesn't care about how > QEMU works, how to configure, compile it and then use it. They > probably use qemu-kvm and libvirt provided by some Linux distribution. > The distro qemu-kvm does not change much so it wouldn't be a problem > for emulator team to fix eventual ABI problems. Distributing device as > dynamic library is simply easier for both teams.
The hardware team can provide a qemu-custom-board binary instead of a bunch of .so files to the driver team. That way the whole emulator can be tested and will never have ABI issues. Device model plugins don't improve this scenario. Stefan
