Re: [Qemu-devel] [RFC PATCH 0/8] Remove stub mon-protocol-event for block

[Paolo Bonzini <pbonzini@redhat.com>]

Il 12/09/2013 14:08, Kevin Wolf ha scritto:
> Am 12.09.2013 um 11:31 hat Paolo Bonzini geschrieben:
>> Il 12/09/2013 11:15, Wenchao Xia ha scritto:
>>> This series will remove the usage of symbols of mon-protocol-event in
>>> qemu-img, qemu-nbd and qemu-io, in short remove the connetion for block
>>> layer.
>>>
>>> Background:
>>>   I am tring to decouple block layer code with other unnnessary components,
>>> and in ./stub there many symbols that qemu-img linked as fake implemtion.
>>> As a first step, I am decouple monitor with block layer code, this is the
>>> first part of it.
>>>   There are still other stub symbols for monitor, which will be solved later.
>>> It seems error handlering is also link with those symbols, and will adjust
>>> that.
> 
>> Patches 1-4 look good.  I'm not sure of the advantage of the last four,
>> however.  The ugly part of monitor_protocol_event is not really the
>> stub, but the dependency on QObject.
>>
>> So, in my opinion a more interesting approach would be to describe
>> events using QAPI types.  Generating the events would require a small
>> amount of code to build QObjects manually, because the event syntax
>> doesn't match exactly a QAPI union, but that is only a technical detail.
> 
> You mean the QAPI schema cannot describe events? Why do you think so,
> and wouldn't this be a reason to extend the schema language?
> 
> The QMP spec describes events like this:
> 
> { "event": json-string, "data": json-object,
>   "timestamp": { "seconds": json-number, "microseconds": json-number } }
> 
> Looks like it could be described as:
> 
> { 'type': 'EventTypeA',
>   'data': {
>       'data': {
>           # event-specific data
>       } } }
> { 'type': 'EventBase',
>   'data': { 'event': 'str'. 'timestamp': {
>       'seconds': 'int', 'microseconds': 'int' } }
> { 'union': 'Event',
>   'base:' EventBase',
>   'discriminator': 'event',
>   'data': {
>       'EVENT_NAME_A': 'EventTypeA'
>   } }

I didn't know about all this cool stuff you added. :)

Paolo