[PATCH 09/11] qdev: Avoid QemuOpts in QMP device_add

[Peter Krempa]

On Fri, Sep 24, 2021 at 11:04:25 +0200, Kevin Wolf wrote:
> Directly call qdev_device_add_from_qdict() for QMP device_add instead of
> first going through QemuOpts and converting back to QDict.
> 
> Note that this changes the behaviour of device_add, though in ways that
> should be considered bug fixes:
> 
> QemuOpts ignores differences between data types, so you could
> successfully pass a string "123" for an integer property, or a string
> "on" for a boolean property (and vice versa).  After this change, the
> correct data type for the property must be used in the JSON input.
> 
> qemu_opts_from_qdict() also silently ignores any options whose value is
> a QDict, QList or QNull.

Sorry for chiming in a bit late, but preferrably this commit should be
postponed to at least the next release so that we decrease the amount of
libvirt users broken by this.

Granted users are supposed to use new libvirt with new qemu but that's
not always the case.

Anyways, libvirt is currently mangling all the types to strings with
device_add. I'm currently working on fixing it and it will hopefully be
done until next-month's release, but preferrably we increase the window
of working combinations by postponing this until the next release.