Re: [Qemu-devel] [PATCH V4 4/7] qmp: Allow to change password on names block driver states.

[Luiz Capitulino <lcapitulino@redhat.com>]

On Mon, 9 Dec 2013 17:48:50 +0100
Benoît Canet <benoit.canet@irqsave.net> wrote:

> Le Monday 09 Dec 2013 à 11:41:09 (-0500), Luiz Capitulino a écrit :
> > On Mon, 9 Dec 2013 17:23:09 +0100
> > Kevin Wolf <kwolf@redhat.com> wrote:
> > 
> > > > > I'm leaning slightly towards the approach that Benoît took, if only for
> > > > > the naming aspect (that is, I also thought of the idea of a bool flag,
> > > > > but didn't suggest it because I didn't like the implications on the
> > > > > naming).  But I can live with either approach, if anyone else has a
> > > > > strong opinion.
> > > > 
> > > > Well, we can pick up any descriptive name 'treat-device-as-a-node',
> > > > 'device-is-a-graph-node'...
> > > 
> > > All devices are represented by nodes, so that doesn't make sense.
> > > If anything, 'interpret-device-name-as-node-name', which at the same
> > > time makes it pretty clear that we're abusing a field for something it
> > > wasn't meant for.
> > 
> > Having two optionals where they can't be specified at the same time
> > and can't be left off at the same time is a clear abuse as well.
> > 
> > The truth is, both proposals are bad. This makes me think that maybe
> > we should introduce a block API 2.0 and deprecate the current one
> > (partly or completely).
> > 
> 
> It took me one year to go from the block filters and block backend
> requirement to the state where my customer allows me to work on block filters.
> 
> Now if we add to this the new requirement of block API 2.0 I think I will soon
> have time to concentrate myself on non qemu projects :(

I don't think it would be something major as far as code is concerned.
What can take a lot of time and energy is to define the API. The QMP
commands implementation would probably be a wrapper around a single (or
a set of) block functions.

Again, I can live with what I suggested because I find it simpler
than your original proposal: no existing field is changed, only one
field is added, and clients can happily omit it if they don't know
what it's about.