Re: [Qemu-devel] [PATCH v2 0/2] Add machine type pc-1.0-qemu-kvm for live migrate compatibility with qemu-kvm

[Alex Bligh]

On 4 Aug 2014, at 14:31, Michael S. Tsirkin <address@hidden> wrote:

> On Fri, Aug 01, 2014 at 08:12:11PM +0100, Alex Bligh wrote:
>> This patch series adds inbound migrate capability from qemu-kvm version
>> 1.0. The main ideas are those set out in Cole Robinson's patch here:
>> http://pkgs.fedoraproject.org/cgit/qemu.git/tree/0001-Fix-migration-from-qemu-kvm.patch?h=f20
>> however, rather than patching statically (and breaking inbound
>> migration on existing machine types), I have added a new machine
>> type (pc-1.0-qemu-kvm) without affecting any other machine types.
>> The existing pc-1.0 machine type is renamed to pc-1.0-qemu-git,
>> with pc-1.0 becoming an alias for one or another, as selected
>> by a configure option (defaulting to pc-1.0-qemu-git, IE no
>> change).
>> 
>> This requires 'hot patching' the VMStateDescription in a couple of
>> places, which in turn is less than obvious as there may be (indeed
>> are for i8259) derived classes. Whilst pretty nausea-inducing, this
>> approach has the benefit of being entirely self-contained.
> 
> Ow come on.
> Just add a flag and select the appropriate format based on it, using
> field_exists.

I don't think it is that simple. All those things are initialised well
before the command line is parsed.

Unless I'm missing what you are saying?

-- 
Alex Bligh