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Re: [Qemu-ppc] [RFC PATCH] target-ppc: Add compatibility between P7/P7+

From: Alexey Kardashevskiy
Subject: Re: [Qemu-ppc] [RFC PATCH] target-ppc: Add compatibility between P7/P7+ and P8E/P8
Date: Sat, 28 Jun 2014 10:00:59 +1000
User-agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0

On 06/28/2014 02:14 AM, Alexander Graf wrote:
> On 27.06.14 17:54, Alexey Kardashevskiy wrote:
>> At the moment POWER7+ and POWER7 CPUs are different incompatible
>> families in QOM. The same is valid for POWER8E and POWER8 CPUs.
>> However, these couples are architecturally equal and there is no
>> good reason, for example, not to let run -cpu POWER7 on the real
>> POWER7+ CPU machine.
>> This introduces one more level in hierarchy of POWERPC CPU classes.
>> New macro POWERPC_FAMILY_2 takes a family class and the parent family
>> class and, for example, for POWER7+ the hierarchy looks like:
>> POWER7-powerpc64-cpu
>> POWER7+-powerpc64-cpu
>> This registers new dynamic POWERPC CPU classes for all classes between
>> the lowest one which matches the real PVR and TYPE_POWERPC_CPU.
>> So for POWER7, it is still going to be just a single dynamic "POWER7"
>> class but for POWER7+ inherited from POWER7 there are going to be
>> 2 dynamic classes  - "POWER7+" and "POWER7" so management software
>> can use both to ensure successful migration.
>> Since POWER7+ inherits from POWER7 and POWER8E from POWER8, this
>> removes recurring pieces of code. CPUs with shorter names were chosen
>> as parents.
>> Signed-off-by: Alexey Kardashevskiy <address@hidden>
>> ---
>> This is rather RFC patch and there is no hurry in reviewing this,
>> and this is not 2.1 material and everyhting, just tried to solve
>> a QOM puzzle here :)
> I'm not sure - I'd rather make sure we have this sorted out for 2.1 so we
> can keep the -cpu list stable.
> Could we make the PVR matching a function callback rather than value+mask?
> Then we could have p7 and p8 just match on 2 different PVR ranges.

>>> bin(0x4d)
>>> bin(0x4b)
>>> bin(0x4c)

4D == POWER8, 4B == POWER8E, 4C - does not exist and when it will, I do not
know what it is going to be.

>>> bin(0x3f)
>>> bin(0x4a)

What should mask look like for P7 and P8?


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