Re: [Qemu-devel] [PATCH] scripts: Add qom-tree script as modern equivalent of info qtree

[Andreas Färber]

Am 07.02.2014 11:41, schrieb Paolo Bonzini:
> Il 05/02/2014 19:08, Andreas Färber ha scritto:
>> http://wiki.qemu.org/Features/QOM#TODO
>>
>> Anthony wants buses to go away completely. So that seems a legacy
>> concept to me even though they do not seem to be gone tomorrow.
> 
> The way I read that, buses would be replaced by controller devices.
> 
> This is unrelated to showing the devices according to the bus topology
> (which still exists in either approach), which is what "info qtree"
> device.  I guess if controller devices existed, you'd add interfaces
> like BusProvider and BusChildEnumerator, or equivalently some "magic"
> properties to do the same, and use that in "info qtree".

Actually my point was that in Anthony's model you get devices on their
controller device simply by looking at link<foo-device> properties on
the foo controller device. No special bus code is required any more!

Apart from Anthony or someone having to do the actual conversion at some
point, the big unanswered question is how do we share code between PCI
bus hosts - for PCI host bridges we can place code in the QOM base type
(think realizing PCIBus with Bandan's series (which I have been refining
the last few days)), but for PCI-PCI bridges where there's two that's
gonna be slightly more difficult sharing-wise.

Andreas

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