Re: [Qemu-devel] [PATCH v2 2/4] spapr: Use DeviceClass::fw_name for device tree CPU node

["Andreas Färber" <afaerber@suse.de>]

Am 30.08.2013 15:53, schrieb Alexey Kardashevskiy:
> On 08/30/2013 11:26 PM, Andreas Färber wrote:
>> Am 30.08.2013 15:21, schrieb Alexander Graf:
>>>
>>> On 16.08.2013, at 00:35, Andreas Färber wrote:
>>>
>>>> Instead of relying on cpu_model, obtain the device tree node label
>>>> per CPU. Use DeviceClass::fw_name when available. This implicitly
>>>> resolves HOST@0 node labels for those CPUs through inheritance.
>>>>
>>>> Whenever DeviceClass::fw_name is not available, derive it from the CPU's
>>>> type name and fill it in for that class with a "PowerPC," prefix for
>>>> PAPR compliance.
>>>
>>> Could we just mandate the fw_name field to always be set for all classes instead?
>>
>> Sure, we can assert it. But we would then need to set fw_name for the
>> various 970 families at least, which I have been using with pseries in
>> the past. Cell and POWER6 are TODO so I'm not concerned about them. Not
>> sure about RS64 that Alexey mentioned - I wouldn't be able to test.
>> Would be bad to regress and abort with CPU models that were working okay
>> before.
> 
> If we generated fw_name as it would have been done by the current helpers,
> how would anything regress?

Well, before, you were talking about assigning "reasonable fw_name
values", and that would for me require knowledge of which value is
reasonable (i.e., correct) for a certain CPU, and I don't have boards to
check most of them.

My proposal would be to just do it for the sPAPR-compatible (not sure if
that is what you meant with "supported"?) CPUs (because that's where we
intend to use it) and mark the ones we don't know exactly with /* ??? */
as done elsewhere in ppc code.

Andreas

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