Re: [Qemu-devel] Re: Live migration protocol, device features, ABIs and other beasts

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Nov 24, 2009 at 01:29:09PM -0600, Anthony Liguori wrote:
> Paolo Bonzini wrote:
>> On 11/24/2009 07:51 PM, Anthony Liguori wrote:
>>>> to make the primary representation of state an XML document
>>
>> Since my brain is not working well today, I'll just point out that of  
>> course I meant "the primary representation of _schemas_ an XML  
>> document" or anything like that.
>>
>>>> or  anything like that (and convert it back to VMState structs at build
>>>> time), it would not be a huge work, and it would give important  
>>>> benefits.
>>>
>>> Like adding tremendous complexity for little to no gain.
>>
>> Anything that could result in a libqemustate or something like that  
>> would be complex, but would have gain.  (Yes, I've seen the smiley  
>> despite aforementioned problems with the brain).
>
> Which would be...?
>
> "Increased flexibility" is not a quantifiable gain.  If there's a  
> particular feature we need to support, let's try to support the feature.
>
> There are bigger fish to fry with live migration than the protocol  
> format.  For instance, we need to do a fair bit of work to build an  
> infrastructure that will let us test this stuff in a sane way so we can  
> avoid introducing things like the pvclock regression.

BTW, I think that the ability to save in old format will
help in this respect: it makes it possible to do some unit
testing without having old qemu lying around.

-- 
MST