Re: [Qemu-devel] [SeaBIOS] [PATCH v2 3/4] i386: generate pc guest info

["Andreas Färber" <afaerber@suse.de>]

Hi Gerd,

Am 24.07.2013 16:42, schrieb Gerd Hoffmann:
>>> This does not satisfy the "should use QOM properties" requirement that
>>> we discussed in the RFC thread.
>>
>> I don't know which part of the RFC thread still applied and
>> which doesn't: at that point you were rejecting the whole
>> approach.
>>
>> I found a mail where you said:
>> 	I'd be a lot happier if we were passing more information to this routine
>> 	and not hard coding it.  For instance, the PCI interrupt assignments,
>> 	the APIC ids, the number of available CPUs, etc.
>>
>> So this is exactly what this code does.
>> What, exactly, would you like to see instead?
>> Create a guest info QOM object, and encode all information used by ACPI
>> generation as properties of this object?
> 
> Don't touch device code for this.
> 
>>>> -void pvpanic_init(ISABus *bus)
>>>> +void pvpanic_init(ISABus *bus, PcGuestInfo *guest_info)
>>>>  {
>>>>      ISADevice *dev;
>>>> -    FWCfgState *fw_cfg = fw_cfg_find();
>>>> +    FWCfgState *fw_cfg = guest_info->fw_cfg;
>>>>      if (!fw_cfg) {
>>>>          return;
>>>>      }
>>>>      dev = isa_create_simple (bus, TYPE_ISA_PVPANIC_DEVICE);
>>>> -    pvpanic_fw_cfg(dev, fw_cfg);
>>>> +    pvpanic_guest_info(dev, guest_info);
>>>>  }
> 
> To pick this one as example:  Instead of patching pvpanic code to stuff
> config info into GuestInfo you should (1) search the device object tree
> for a pvpanic device and (b) if present read the ioport property to
> figure the base address.

Yeah, the above does not feel so nice from a QOM view (didn't review the
ACPI series yet).

> /me suggests to check out qmp_qom_get() in qmp.c.  Some qom aequivalent
> for qdev_find_recursive would be handy, dunno whenever such a thing
> exists already, Andreas?

Not sure what's needed here? object_resolve_path() and
object_foreach_child() come to mind...

Regards,
Andreas

> I'd tend to accept GuestInfo as temporary thing for stuff which can't be
> figured using qom properties today.  Anthony might disagree though.
> 
> cheers,
>   Gerd
> 


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