Re: [Qemu-devel] [Qemu-ppc] [PATCH 1/2] PPC: Fix interrupt MSR value within the PPC interrupt handler.

[Scott Wood]

On 03/29/2012 04:11 AM, Mark Cave-Ayland wrote:
>>> What about POWERPC_EXCP_40x?  And are all the classic chips OK with the
>>> 2.06B implementation?
>>
>> Hrm, yeah.  I think what you ought to do is to use the new logic just
>> for the "classic" exception models.  Have the default branch remain
>> the one that just masks ME.  That's wrong, but it's the same wrong as
>> we have already, and we can fix it later once we've verified what the
>> right thing to do is for 40x and BookE.
> 
> I'm actually coming at this from a fixing what was potentially an
> OpenBIOS bug rather than a PPC angle, so I have to admit I have no I
> idea which ones are the "classic" exception models. Would you consider
> this to be just EXCP_STD, EXCP_6* and EXCP_7*?

Also POWERPC_EXCP_G2, and maybe POWERPC_EXCP_970?  Even on server
there's a question of whether it's a 2.06 chip or previous version of
the architecture.

One thing that sticks out for classic chips that is missing here is
MSR[POW], which should be cleared on exceptions.

-Scott