Re: [Qemu-ppc] [Qemu-devel] [RFC PATCH] powerpc: add PVR mask support

[Alexander Graf]

On 15.08.2013, at 17:11, Andreas Färber wrote:

> Am 15.08.2013 15:12, schrieb Anthony Liguori:
>> Everyone is talking past each other and no one is addressing the real
>> problem.  There are two distinct issues here:
>> 
>> 1) We have two ABIs that cannot be changed unless there's a very good
>>   reason to.  Alexey's original patch breaks both.  The guest ABI
>>   cannot change given a fixed command line.
>> 
>>   IOW, the exposed PVR value for -cpu POWER7 cannot change across
>>   versions of QEMU or when running on different hardware.  This breaks
>>   live migration and save/resume.
>> 
>>   We also cannot break the command line interface.  If the last version
>>   of QEMU supported -cpu POWER7_v2.1, then we must continue to support
>>   that.
> 
> 1a) How should -cpu 0xDEADBEEF or -cpu DEADBEEF behave.
> 
>    I expect it to error out as before
>    rather than applying the same fuzz/mask that -cpu host might.

I actually think it'd make sense to apply the same fuzz/mask, don't you think?


Alex