Re: [Qemu-ppc] [Qemu-devel] [PATCH 05/17] pseries: savevm support for XICS interrupt controller

[Alexey Kardashevskiy]

On 07/09/2013 10:49 AM, Anthony Liguori wrote:
> On Mon, Jul 8, 2013 at 7:06 PM, Alexey Kardashevskiy <address@hidden> wrote:
>>> You should tie the vmstate section to DeviceState::vmsd.  You only need
>>> to do this because you haven't converted everything to QOM yet.
>>>
>>> Please do that to avoid these hacks.
>>
>>
>> How? I want to support migration from xics to xics-kvm and vice versa.
>> vmsd cannot be inherited and even if they could, different device names
>> would kill that support.
> 
> Please look at hw/intc/i8259_common.c and then hw/i386/kvm/i8259.c and
> hw/i386/intc/i8259.c.

btw do I have to put xics_kvm.c to hw/ppc64/kvm (which does not exist yet)
or to hw/intc? What is the system here? I am really confused.

> The vmsd is in the common base class shared between the KVM version
> and the non-KVM version.  As long as the subclasses don't introduce
> any new state members, you can safely migrate between the two devices.


btw xics-kvm does not introduce new members but does have very different
.pre_save and .post_load. This actually was the whole point of splitting
xics into xics and xics-kvm. I cannot see how I can fix it without hacks.
Property's can be inherited from a parent class (?) but VMStateDescription
cannot.


> You should consider splitting the implementations up into separate
> files just like i8259 too.




-- 
Alexey