On Tue, 18 Jun 2024 at 10:30, Paolo Bonzini <pbonz...@redhat.com> wrote: > > On Tue, Jun 18, 2024 at 11:13 AM Daniel P. Berrangé <berra...@redhat.com> > wrote: > > I wonder if starting with a device implementation is perhaps the > > wrong idea, in terms of a practical yet simple first step. > > > > As devices go, the pl011 device is simple, but compared to other > > QOM impls in QEMU, devices are still relatively complex things, > > especially if we want to write against safe abstraction. > > It's true, but I think _some_ complexity provides a better guide as to > what are the next step. > > I think it's clear that they are, not in this order: > * calling QOM methods (Chardev) > * implementing QOM objects > * implementing QOM devices > ** qdev properties > ** MemoryRegion callbacks > * implementing Chardev callbacks > * general technique for bindings for C structs (Error, QAPI)
Right, this is why I suggested the pl011 as a device: I felt it provided enough complexity in terms of where it interconnects to the rest of QEMU to be a realistic way to find out where the points of difficulty are, without being super complicated simply as a device. We don't need to have fully worked out solutions to these things in the first pass, but I agree with Paolo that we do want to have a clear path forward that says "this is what we're expecting the solutions to these points of difficulty to end up looking like and how we plan to get there". thanks -- PMM
