Re: [Qemu-devel] [PATCH 00/18] qom: dynamic properties and composition tree

[Avi Kivity <avi@redhat.com>]

On 11/30/2011 11:03 PM, Anthony Liguori wrote:
> This is a follow up to my previous series to get us started in the QOM
> direction.  A few things are different this time around.  Most notably:
>
>  1) Devices no longer have names.  Instead, path names are always used to
>     identify devices.
>
>  2) In order to support (1), dynamic properties are now supported.
>
>  3) The concept of a "root device" has been introduced.  The root device is
>     roughly modelling the motherboard of a machine.  This type is a container
>     type and it's best to think of it as something like a PCB board I guess.
>
> To try it out, here's an example session:
>
> Launch:
>
> anthony@titi:~/build/qemu$ x86_64-softmmu/qemu-system-x86_64 -hda ~/images/linux.img -snapshot -device virtio-balloon-pci,id=foo -qmp unix:/tmp/server.sock,server,nowait
>
> Explore the object model:
>
> anthony@titi:~/git/qemu/QMP$ ./qom-list /
> peripheral/
> i440fx/
> anthony@titi:~/git/qemu/QMP$ ./qom-list /i440fx/
> piix3/
> anthony@titi:~/git/qemu/QMP$ ./qom-list /i440fx/piix3
> rtc/
> anthony@titi:~/git/qemu/QMP$ ./qom-list /i440fx/piix3/rtc
> date
> base_year
> anthony@titi:~/git/qemu/QMP$ ./qom-get /i440fx/piix3/rtc.date
> tm_sec: 33
> tm_hour: 21
> tm_mday: 30
> tm_year: 111
> tm_mon: 10
> tm_min: 2
>

So all of these become ABIs, right?

We need good tools to allow easy review of the ABI bits hiding in
patches, and to maintain ABI compatibility.  Something like
qemu-print-abi that dumps all properties for all devices.  Patches could
show the ABI changes by including a diff of the output of this program
from before and after a change, and we could add similar tests for
backwards compatibility.

-- 
error compiling committee.c: too many arguments to function