Re: [Qemu-devel] [Qemu-ppc] [PATCH] target-ppc: Change default machine for 64-bit

[Alexander Graf]

On 17.05.2013, at 09:42, Andreas Färber wrote:

> Am 17.05.2013 06:25, schrieb David Gibson:
>> Currently, for qemu-system-ppc64, the default machine type is 'mac99'.
>> Since the mac99 machine is not being actively maintained, and shows quite
>> a few signs of bitrot,
> 
> Please be more specific than making such general claims in a commit
> message! As the default machine it certainly compiles, so where are you
> seeing bitrot? The DEC bridge cleanup that I once started kind of
> depends on the PCI cleanup you recently looked into.

The mac99 machine for 64bit is actually worse than anything bitrot could give 
you. It emulates a machine that in its form never possibly could have existed 
in real hardware, which makes it very fragile and dependent on the guest's 
mercy to handle this gracefully.

Given the current state and amount of development on the pseries target, I 
think it makes sense to declare that as the default for qemu-system-ppc64.

I would still love to see -M mac99 emulate a proper U2 or U1 based system for 
32bit. And I would also love to see a real U4 based emulation model come up for 
qemu-system-ppc64. But I doubt I'll have time to work on either :).


Alex