Re: [Qemu-devel] [RFC PATCH 0/4] Fix subsection ambiguity in the migration format

[Anthony Liguori]

On 07/31/2011 05:48 AM, Dor Laor wrote:
> On 07/30/2011 01:28 AM, Anthony Liguori wrote:
> > No, not at all. Just that converting everything to VMState isn't a
> > prerequisite for building a more robust migration protocol.
>
> The main thing is to priorities the problems we're facing with.
> - Live migration protocol:
> - VMState conversion is not complete

But this is not a problem because it doesn't gate anything.  That's my 
point.

> - Live migration is not flexible enough (even with subsections)

To make it more flexible, we need to be able to marshal to an internal 
data structure that we can transform in more flexible ways.

> - Simplify destination cmdline for machine creation

This needs qdev fixing.

> - Qdev
> - conversion is not complete
> - Machine + devices description are complex and have hidden glue

This is a hard problem.

> - Qapi
> - Needs merging

We merged the first part (which includes the new QMP server).  The work 
is done for converting the actual QMP commands.

> - QOB
> - Only the beginning
>
> So overall there are many parallel projects, probably more than the
> above. The RightThink(tm) would be to pick the ones that we can converge
> on and not try to handle all in parallel. There are problems we can live
> with. Engineering wise it might not be a beauty but they can wait (for
> instance dark magic to create the machines). There are some that prevent
> adding new features or make the code hard to support w/o them.
>
> Cheers,
> Dor
>
> ps: how hard is to finish the vmstate conversion? Can't we just assume
> not converted code is not functional and just remove all of it?

No.  VMState is a solution looking for a problem.  Many important device 
models are still not converted and ultimately, it doesn't solve the 
problem we're really trying to solve.

Regards,

Anthony Liguori

> > Regards,
> >
> > Anthony Liguori