Re: [Qemu-devel] [RFC PATCH 0/9] qemu capabilities reporting and config changes

[Anthony Liguori]

On 03/19/2012 11:45 AM, Paolo Bonzini wrote:
> Il 19/03/2012 17:41, Anthony Liguori ha scritto:
> > On 03/19/2012 11:33 AM, Paolo Bonzini wrote:
> > > Il 19/03/2012 17:31, Anthony Liguori ha scritto:
> > > > > > It also plumbs the existing command line options through QemuOpts via
> > > > > > a special
> > > > > > 'system' section.  This means that any command line option can be
> > > > > > specified via
> > > > > > readconfig and that the combination of -nodefconfig and -writeconfig
> > > > > > should give
> > > > > > you exactly the same guest in a repeatable fashion.
> > > > >
> > > > > I don't like this because it turns command-line options into ABI.
> > > >
> > > > It's already an ABI, no?
> > >
> > > Right, sorry.  Into configuration file ABI, which is supposed to be the
> > > "cleaner" ABI.
> >
> > Right, the basic premise of this series is "perfect is the enemy of
> > good".  I think we do ourselves more harm than good trying to come up
> > with a clean new interface instead of just cleaning up the bits behind
> > what we previously had.
>
> Yeah,it depends on what you consider good. :)  My direction was like
> "let's cover 90% of the usecases with a decent syntax"; yours is "let's
> cover 100% of the usecases even though the syntax may stink".
>
> (There's time to convert -display before 1.1, which would make 99%).

So if we had 99% with good syntax and 1% with a syntax that stinks, that seems 
reasonable to me, no?

> > > > > Also, it puts there some options for which -writeconfig is actually
> > > > > able to produce a QemuOpts equivalent, such as -monitor.
> > > >
> > > > That may be a bug depending on what your concern is.  Can you be more
> > > > specific?
> > >
> > > If you write "-monitor stdio" with your series, do you get one or two
> > > monitors in the resulting configuration file?
> >
> > Two, I now understand what you're saying.  Let me look into fixing
> > that.  This is more about -writeconfig.  We need to record the origin of
> > a particular QemuOpt and have -writeconfig spit out only things that
> > came from -readconfig.
>
> I think it's simpler than that.  Just don't mark as gdef those options
> that are backed internally by QemuOpts.

That's already done.  But given the way the parsing works, gdef and def options 
are both stored in system's QemuOpts.  I can fix that though...

Regards,

Anthony Liguori

> Paolo