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

[Damien Hedde]

On 10/1/21 16:42, Peter Krempa wrote:
> 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.
> 
> 

Switching to qdict is really an improvement I think.

If we choose to keep legacy behavior working for now, I think we should 
find a way to still do this switch. Maybe we can temporarily keep the 
str_to_int and str_to_bool conversion when converting the qdict to the 
qdev properties  afterward ?

Damien