Re: [Qemu-devel] [qemu-devel][libvirt] Default machine type setting for ppc64

[Peter Maydell]

On 21 May 2013 11:01, Daniel P. Berrange <address@hidden> wrote:
> On Tue, May 21, 2013 at 07:55:27PM +1000, Paul Mackerras wrote:
>> I think libvirt needs some more sensible way to ask qemu what its
>> capabilities are.  Currently it has no way to ask qemu "what machines
>> can you emulate with kvm acceleration?"  If the user has asked for a
>> KVM domain then the default machine should be one that can be provided
>> by KVM.  At present it isn't, on PowerPC.
>
> If QEMU can provide more intelligent info in this respect, then
> libvirt can use it.

I think this would make sense. Currently for ARM to get KVM
acceleration you have to use a specific guest CPU (A15), and
so you have to use a machine which supports that CPU (currently
just vexpress-a15). But we don't expose any way for libvirt to
tell that it needs an A15 or which machine models support which
CPUs. In fact we don't even give a sensible error message if
you try to use a wrong CPU, we'll just blithely push ahead
and behave very weirdly.

thanks
-- PMM