[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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

From: Alexander Graf
Subject: Re: [Qemu-ppc] [RFC PATCH] target-ppc: Add compatibility between P7/P7+ and P8E/P8
Date: Fri, 27 Jun 2014 18:14:46 +0200
User-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:24.0) Gecko/20100101 Thunderbird/24.6.0

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:

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.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]