Re: [Qemu-devel] qdev for programmers writeup

2011-07-11 Thread Peter Maydell
On 11 July 2011 11:20, Paolo Bonzini wrote: This is cool; more qdev documentation is really useful. One point I'd like clarification on is when you need to invent a new bus type. Sometimes it's pretty obvious because there's a real hardware bus type there (PCI, SCSI) that you're modelling. It's

Re: [Qemu-devel] qdev for programmers writeup

2011-07-11 Thread Paolo Bonzini
On 07/11/2011 12:46 PM, Peter Maydell wrote: One point I'd like clarification on is when you need to invent a new bus type. As rarely as possible, but as often as necessary? :P New buses limit reusability of the models, but you need one whenever the existing buses do not express how two devic

Re: [Qemu-devel] qdev for programmers writeup

2011-07-11 Thread Peter Maydell
On 11 July 2011 13:48, Paolo Bonzini wrote: > On 07/11/2011 12:46 PM, Peter Maydell wrote: >>Paolo wrote: >>> Together with such >>> a bus type there should be a single root board-specific device that is >>> attached to SysBus.  An interrupt controller is usually a good candidate >>> for this beca

Re: [Qemu-devel] qdev for programmers writeup

2011-07-11 Thread Paolo Bonzini
On 07/11/2011 04:44 PM, Peter Maydell wrote: That's true, but the only way to plug in those device models would be with C code. You cannot just play with -device to reconfigure them. I think the C source level reuse is more important and more useful than plugging stuff around with -device, bec

Re: [Qemu-devel] qdev for programmers writeup

2011-07-11 Thread Peter Maydell
On 11 July 2011 16:29, Paolo Bonzini wrote: > On 07/11/2011 04:44 PM, Peter Maydell wrote: >> (Also if you have one bus type >> per board then you're still very limited in what you can do with -device >> because you can't plug in some random other sysbus device anyway.) > > I'm not talking about o

Re: [Qemu-devel] qdev for programmers writeup

2011-07-12 Thread Paolo Bonzini
On 07/11/2011 06:47 PM, Peter Maydell wrote: On 11 July 2011 16:29, Paolo Bonzini wrote: On 07/11/2011 04:44 PM, Peter Maydell wrote: (Also if you have one bus type per board then you're still very limited in what you can do with -device because you can't plug in some random other sysbus devic