Re: [Qemu-devel] [PATCH 2/5] socket: Add a reconnect option.

[Anthony Liguori]

On 02/01/2010 04:44 PM, Ian Molton wrote:
> Anthony Liguori wrote:
>
>    
> > I went back and looked at the last series and found my feedback.  I had
> > suggested that instead of automatically reconnecting, a mechanism should
> > be added for a user to initiate a reconnect.
> >      
> This sounds useful
>
>    
> > Additionally, we should emit events upon disconnect through QMP (now
> > that we have that functionality).
> >      
> This also.
>
>    
> > The main reason I dislike automatic reconnecting is that there is no
> > correct way to handle the period of time while the VM is disconnected.
> >      
> This is fine for egd protocol, the guest will just run low on entropy in
> the meantime. Nothing should break.
>    

Right, but you're adding a generic piece of functionality.  For 
instance, what's the result of using reconnect with virtio-console?  Is 
this something that is going to work well?

> > Auto reconnecting is implementing a policy to handle the failure within
> > QEMU which is not universally the correct choice.  This isn't so bad
> > except for the fact that you aren't providing the mechanisms for users
> > to implement other policies which means they're stuck with this
> > particular policy.
> >      
> Perhaps this feature could be added if needed in future? It seems a bit
> ambitious to get all this 'right' with no use cases to test against.
>    

I'm all for doing things incrementally but there has to be a big picture 
that the incremental bit fits into otherwise you end up with a bunch of 
random features that don't work together well.

Honestly, I'd strongly suggest splitting the reconnect logic out of the 
series when resubmitting.  I think it's just too hacky with too weak of 
a justification.  If you really want this functionality, we can discuss 
the right approach for doing it but it's gotta be done in a way that's 
not introducing a one-off case just for the random number generator.

Regards,

Anthony Liguori

> -Ian
>