Re: [PATCH v5 3/8] qapi: Restrict balloon-related commands to machine code

[Markus Armbruster]

David Hildenbrand <david@redhat.com> writes:

>> Am 14.09.2020 um 11:42 schrieb Philippe Mathieu-Daudé <philmd@redhat.com>:
>> 
>> +Laurent and David
>> 
>>> On 9/14/20 11:16 AM, Markus Armbruster wrote:
>>> Philippe Mathieu-Daudé <philmd@redhat.com> writes:
>>> 
>>>> Only qemu-system-FOO and qemu-storage-daemon provide QMP
>>>> monitors, therefore such declarations and definitions are
>>>> irrelevant for user-mode emulation.
>>>> 
>>>> Restricting the balloon-related commands to machine.json
>>>> allows pulling less declarations/definitions to user-mode.
>>> 
>>> How this affects user mode is not obvious to (ignorant) me.  Can you
>>> provide a clue?
>> 
>> I guess this was discussed with David at some point.
>> 
>> Maybe the QMP commands are not exposed via HMP, making this
>> code unreachable?
>> 
>> Anyhow user-mode binaries don't use the memory ballooning feature,
>> this is specific to system-mode emulation.
>> 
>> Laurent/David, do you have some more trivial explanation?
>
> Agreed.
>
> No memory ballooning device -> no memory ballooning :)

I understand why user mode doesn't need device models.  What I don't
understand offhand is how balloon-related stuff in misc.json ends up
pulling "declarations/definitions to user-mode".  What exactly is being
pulled where before the series, and no more afterwards?

Is it just the code generated for the QAPI stuff you move, or is it
more?