Re: [Qemu-devel] [PATCH 7/7] chardev: add hotplug support.

[Gerd Hoffmann <kraxel@redhat.com>]

On 10/12/12 11:40, Paolo Bonzini wrote:
> Il 12/10/2012 11:26, Gerd Hoffmann ha scritto:
>> This patch adds chardev_add and chardev_del monitor commands.
>>
>> chardev_del is pretty straight forward, it just takes an id argument and
>> zaps the chardev specified.
>>
>> chardev_add is more tricky as there are tons of arguments for the
>> different backends.  The hmp version limited to the most common use
>> cases, especially when it comes to sockets:  You can only specify port
>> (tcp) or path (unix) and qemu will create a listening socket.  For
>> example this ...
>>
>>    (qemu) chardev_add foo socket 42
>>
>> ... will do the same as ...
>>
>>    -chardev socket,id=foo,port=42,server,nowait
> 
> Why not
> 
> chardev_add socket,id=foo,port=42,server,nowait
> 
> ?

Yea, maybe, but see below.

>> +{ 'command': 'chardev_add', 'data': {'id'      : 'str',
>> +                                     'backend' : 'str',
>> +                                     'path'    : 'str',
>> +                                     'name'    : 'str',
>> +                                     'host'    : 'str',
>> +                                     'port'    : 'str',
> 
> You cannot pass NULLs via QMP, so these need to be optional.

Fixed.

> I suggest that you implement the commands in a similar way as netdev_add.

Why?  Isn't the whole point of using josn is that you'll get the stuff
from the josn parser & marshaller in a usable form instead of having it
to feed into yet another parser?  I think the only reason netdev_add
exists in the current form is that it predates qmp.

cheers,
  Gerd