Re: [Qemu-devel] [PATCH qemu] qom: Document qom/device-list-properties implementation specific

[Paolo Bonzini]

On 03/05/2018 08:22, Alexey Kardashevskiy wrote:
> On 2/5/18 7:50 pm, Paolo Bonzini wrote:
>> On 02/05/2018 11:33, Alexey Kardashevskiy wrote:
>>>>>>>> +# Note: the handler creates an object, enumerates properties and 
>>>>>>>> destroys
>>>>>>>> +# the object so it only lists properties created in 
>>>>>>>> TypeInfo::instance_init().
>>>>>>>> +# Since the instance_init() callback of the device object adds
>>>>>>>> +# DeviceClass::props as object properties, they will be listed as 
>>>>>>>> well.
>>>
>>> There are roughly 400 of realize(), this is will take a bit of time :)
>>> imho what it does belongs to .json, why it does exactly that belongs to the
>>> git commit log. I'll walk through the realize() hook though, educate
>>> myself, at least :)
>>
>> Cheer up, there are only 300 callers of object_property_add_* (apart
>> from object_property_add_child which is generally not an issue).  You
>> could look at those instead. :)
> 
> I did not have to go too far for an example:
> 
> piix4_pm_realize() calls piix4_pm_add_propeties() and acpi_pcihp_init() and
> piix4_acpi_system_hot_add_init() and these guys create
> bool/uint8_ptr/uint16_ptr/uint32_ptr properties:
> 
> 
> 
> hw/acpi/piix4.c|477| object_property_add_uint8_ptr(OBJECT(s),
> ACPI_PM_PROP_ACPI_ENABLE_CMD,
> hw/acpi/piix4.c|479| object_property_add_uint8_ptr(OBJECT(s),
> ACPI_PM_PROP_ACPI_DISABLE_CMD,
> hw/acpi/piix4.c|481| object_property_add_uint32_ptr(OBJECT(s),
> ACPI_PM_PROP_GPE0_BLK,
> hw/acpi/piix4.c|483| object_property_add_uint32_ptr(OBJECT(s),
> ACPI_PM_PROP_GPE0_BLK_LEN,
> hw/acpi/piix4.c|485| object_property_add_uint16_ptr(OBJECT(s),
> ACPI_PM_PROP_SCI_INT,
> hw/acpi/piix4.c|487| object_property_add_uint32_ptr(OBJECT(s),
> ACPI_PM_PROP_PM_IO_BASE,
> hw/acpi/piix4.c|642| object_property_add_bool(OBJECT(s), "cpu-hotplug-legacy",

Thanks!  Though that could be done in instance_init as well.  ICH9
already does it that way.

>> Seriously, I think the problem with the comment is only that the reader
>> most likely doesn't care about instance_init() or props, as those are
>> QEMU implementation details.
>
> So I am putting the chunk below (cut-n-pasted from this thread) for each
> command (i.e. twice) instead of my stuff and repost?

Yes, please.

paolo