Re: [Qemu-devel] [PATCH v2] trace: [qmp] Add QAPI/QMP commands to query and control event tracing state

["Lluís Vilanova" <vilanova@ac.upc.edu>]

Markus Armbruster writes:

> Lluís Vilanova <vilanova@ac.upc.edu> writes:
>> Markus Armbruster writes:
>> 
>>> Lluís Vilanova <vilanova@ac.upc.edu> writes:
>>>> Also removes old "trace-event", "trace-file" and "info trace-events" HMP
>>>> commands.
>> 
>>> We gain the ability to control trace via QMP, but lose the ability to
>>> control it via HMP, correct?
>> 
>> Right. I can keep the HMP commands, but doing so requires exposing the internal
>> trace event identifier number in the QMP interface. Also, "trace-file" cannot be
>> implemented on top of the current QMP commands, and is specific to the "simple"
>> tracing backend.

> Would rough feature-parity with QMP be feasible with new HMP commands on
> top of the QMP interfaces, completely ignoring HMP backward
> compatibility?

Except for "trace-file", it would be quite easy, yes. For "trace-file", we can
either keep the current HMP implementation, or add new QMP commands to support
it (I'd rather devote my time to something else, though).


Thanks,
  Lluis

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