[libvirt] [PATCH libvirt master v2] interface type: add udp socket support

[Laine Stump]

On 08/31/2015 04:06 PM, Jonathan Toppins wrote:
> On 08/31/2015 03:25 PM, Guido Günther wrote:
>> Hi,
>> On Sat, Aug 29, 2015 at 04:19:10PM -0400, Jonathan Toppins wrote:
>>> Adds a new interface type using UDP sockets, this seems only applicable
>>> to QEMU but have edited tree-wide to support the new interface type.
>>>
>>> The interface type required the addition of a "localaddr" (local
>>> address), this then maps into the following xml and qemu call.
>>>
>>> <interface type='udp'>
>>
>>
>> Sine we do have
>>
>>       <interface type='mcast'>
>>
>> already wouldn't it be better to have something like
>>
>>        <interface type='ucast' protocol='udp'>
>>
>
> This possibly could be better, my concern would be now tcp is 
> configured differently than udp, no? Or are you saying something like:
>
>     <interface type='ucast' protocol='udp|tcp'>

I think the case of a tcp connection is already handled by <interface 
type='client'> and <interface type='server'> together, so that doesn't 
seem likely to happen. I suppose it's possible someone would come up 
with an sctp-based transport in the future though. I'm undecided about this.


>
> My concern here is this would be a bigger change and does libvirt have 
> a stable xml configuration guarantee?

libvirt's guarantee of 100% backward-compatible stable API (both 
functions and XML) is one of the big reasons why we worry over this kind 
of detail so much :-) (so yeah, once it goes in, we will continue to 
accept it forever even if we later wish we had done it a different way)