Re: [Qemu-devel] Re: Planning for 0.13

[Anthony Liguori <aliguori@linux.vnet.ibm.com>]

On 01/06/2010 09:16 AM, Michael S. Tsirkin wrote:
> How otherwise would scripts know how to talk to qemu?
> Just just happens to match command line format you say?
> And the way to discover what that format is ... how exactly?
>
> Look, yes we could split this stuff out but this is just maintainance
> headache, each change in backend will now need to be done in multiple
> places, we'll have to care about old scripts, new scripts, it's just a
> mess and at the end we will get existing functionality back and codebase
> which is harder to debug and develop.
>    

A helper is semantics equivalent to passing an fd from a management 
tool.  All of the problems you describe are equally applicable to that 
model.

The question is, should we take in code in qemu to support any possible 
mechanism of creation of networking or should we just make sure their 
all possible by passing in an appropriate fd.

Having helpers does not mean that we would have no backends built into 
qemu.  It just means that's it's possible to create backends outside of 
qemu.

Of course, we need to evalute whether a new backend should be in qemu or 
outside of qemu but that's something to handle on a case-by-case basis.

Regards,

Anthony Liguori