Re: [Qemu-devel] [PATCH 09/14] qdev: connect some links and move type to object

[Andreas Färber]

Am 19.04.2012 16:53, schrieb Anthony Liguori:
> On 04/19/2012 09:46 AM, Andreas Färber wrote:
>> Am 19.04.2012 00:38, schrieb Anthony Liguori:
>>> On 04/18/2012 04:25 PM, Andreas Färber wrote:
>>>> Am 18.04.2012 22:56, schrieb Anthony Liguori:
>>>>> This makes sysbus part of the root hierarchy and all busses children
>>>>> of their
>>>>> respective parent DeviceState.
>>>>>
>>>>> Signed-off-by: Anthony Liguori<address@hidden>
>>>>> ---
>>>>>    hw/qdev.c    |   11 +++++------
>>>>>    qom/object.c |   12 ++++++++++++
>>>>>    2 files changed, 17 insertions(+), 6 deletions(-)
>>>>>
>>>>> diff --git a/hw/qdev.c b/hw/qdev.c
>>>>> index 26e6f09..b5eef22 100644
>>>>> --- a/hw/qdev.c
>>>>> +++ b/hw/qdev.c
>>>>> @@ -427,6 +427,7 @@ static void do_qbus_create_inplace(BusState *bus,
>>>>> const char *typename,
>>>>>        if (parent) {
>>>>>            QLIST_INSERT_HEAD(&parent->child_bus, bus, sibling);
>>>>>            parent->num_child_bus++;
>>>>> +        object_property_add_child(OBJECT(parent), bus->name,
>>>>> OBJECT(bus), NULL);
>>>>>        } else if (bus != main_system_bus) {
>>>>>            /* TODO: once all bus devices are qdevified,
>>>>>               only reset handler for main_system_bus should be
>>>>> registered here. */
>>>>> @@ -456,6 +457,8 @@ static void main_system_bus_create(void)
>>>>>        /* assign main_system_bus before qbus_create_inplace()
>>>>>         * in order to make "if (bus != main_system_bus)" work */
>>>>>        main_system_bus = qbus_create(TYPE_SYSTEM_BUS, NULL,
>>>>> "main-system-bus");
>>>>> +    object_property_add_child(object_get_root(), "sysbus",
>>>>> +                              OBJECT(main_system_bus), NULL);
>>>>
>>>> So this is adding /sysbus. Shouldn't this rather go into
>>>> /unassigned/sysbus?
>>>
>>> What would sysbus be assigned too?  I think sysbus is a really special
>>> case and belongs in the /root directory.
>>
>> I suggested [qdev_get_machine()]/unassigned because of no explicit parenting.
> 
> Yes, but I view /machine/unattached as a TODO list.  I'd like to
> completely eliminate that hierarchy for PC in 1.2.
> 
> But if we stick sysbus in there, it needs to exist forever because
> there's no right place for sysbus to exist.

I thought SysBus would go away for 1.2 as well? AFAIU SysBus has no real
bus state and is just a container for devices because qdev requires
devices to be attached to a bus. SysBusDevices could then become direct
childs of /machine, and we'd need no special sysbus node at all long-term.

Andreas

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