Re: -chardev with a JSON argument (was: [PATCH] chardev: introduce 'reconnect-ms' and deprecate 'reconnect')

[Kevin Wolf <kwolf@redhat.com>]

Am 14.09.2024 um 10:42 hat Markus Armbruster geschrieben:
> Peter Krempa <pkrempa@redhat.com> writes:
> 
> > This is a little off-topic:
> >
> > So I wanted to make libvirt use the new parameter to stay ahead
> > deprecation. I've applied this patch to qemu, dumped capabilities and
> > pretty much expected a bunch of test cases in libvirt fail as they'd be
> > using a deprecated field as libvirt is supposed to validate everything.
> >
> > And the test suite passed unexpectedly. I've dug further and noticed
> > that for some reason libvirt doesn't still use JSON parameters for
> > -chardev (which is the pre-requisite for validation).
> >
> > I've also noticed that at some point I attempted to convert it over
> > witnessed by having an (unused) capability named QEMU_CAPS_CHARDEV_JSON
> > that I've introduced.
> >
> > My questions are:
> > 1) Does '-chardev' accept JSON identical to 'chardev-add' QMP command?
> 
> Sadly, no.
> 
> How badly do you want it?

I suppose even my old patches to fully QAPIfy -chardev could be revived,
which would not only add JSON support, but also make sure that
everything that works in JSON also works with keyval syntax, both ways
stay in sync in the future and that you can access non-scalar options
without JSON:

https://repo.or.cz/qemu/kevin.git/shortlog/refs/tags/qapi-alias-chardev-v4

Without QAPI aliases, they will have to contain some ugly code to do the
compatibility conversion, but whatever can be generated can also be
written manually...

Kevin