Re: [Qemu-devel] [PATCH v3] apic: bump emulated lapic version to 0x14 on pc machines >= 2.1

[Don Slutz <dslutz@verizon.com>]

On 05/01/14 14:52, Alexander Graf wrote:
>
> On 01.05.14 19:22, Gabriel L. Somlo wrote:
>> On Wed, Apr 30, 2014 at 09:44:32PM +0200, Alexander Graf wrote:
>>>> diff --git a/hw/intc/apic.c b/hw/intc/apic.c
>>>> index 2f40cba..4480bc4 100644
>>>> --- a/hw/intc/apic.c
>>>> +++ b/hw/intc/apic.c
>>>> @@ -32,6 +32,8 @@
>>>>   #define SYNC_TO_VAPIC                   0x2
>>>>   #define SYNC_ISR_IRR_TO_VAPIC           0x4
>>>> +uint8_t apic_version = 0x14;
>>> Is there any way to make this a qdev/qom device property rather than
>>> a global?
>> If there is, and anyone with a better understanding of qom/qdev
>> has an example I could follow, that would be much appreciated!
>>
>> As far as I could comprehend it since I started looking at it last
>> night, the apic_class_init() functions run before pci_init() in
>> pc_[q35|piix].c knows which machine type we have, but the
>> apic_realize() functions (which appear to be the actual apic
>> "constructors") run after that.
>>
>> The obvious alternative to having one global apic version would be
>> to add a field to APICCommonClass or APICCommonState, and then somehow
>> modify the default (set in apic_class_init()) from pci_init()
>> according to the machine version; After that, each apic may refer to
>> its private data member "version" when needed.
>>
>> So, is qom/qdev basically boiling down to a set of macros that can
>> translate something like "qom_set_property(apic_instance, version, 0x14);"
>> into "apic_instance.version = 0x14;" ?
>
> With qdev we basically had an array of constructor parameters in the qdev definition. You could set these from the outside between create and init, basically:
>
>   dev = dev_create()
>   set_prop(dev, "foo", bar);
>   dev_init(dev)
>
> which semantically translated to
>
>   dev = new dev(foo = bar);
>
> The way to do this with QOM is similar, but I keep forgetting the details. I'm sure you'll easily find out :).
>
>

It looks like

http://permalink.gmane.org/gmane.comp.emulators.qemu/268337

(which is a reply to a change I am working on that is in the same place)

Hope this helps.
     -Don Slutz

> Alex
>
>