Re: [Qemu-devel] Re: [PATCH 10/15] virtio-serial: Add QMP events for failed port/device add

From: Anthony Liguori <aliguori@linux.vnet.ibm.com>
To: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Juan Quintela <quintela@redhat.com>,
	qemu list <qemu-devel@nongnu.org>,
	Gerd Hoffmann <kraxel@redhat.com>,
	Amit Shah <amit.shah@redhat.com>
Subject: Re: [Qemu-devel] Re: [PATCH 10/15] virtio-serial: Add QMP events for failed port/device add
Date: Fri, 26 Mar 2010 11:51:25 -0500	[thread overview]
Message-ID: <4BACE60D.6080904@linux.vnet.ibm.com> (raw)
In-Reply-To: <20100326112903.712262b9@redhat.com>

On 03/26/2010 09:29 AM, Luiz Capitulino wrote:
> On Fri, 26 Mar 2010 18:56:20 +0530
> Amit Shah<amit.shah@redhat.com>  wrote:
>
>    
>> On (Fri) Mar 26 2010 [10:14:02], Luiz Capitulino wrote:
>>      
>>>>>> +
>>>>>> +VIRTIO_SERIAL
>>>>>> +-------------
>>>>>>              
>>>>>   It should be VIRTIO_SERIAL_ADD.
>>>>>            
>>>> What about other events that VIRTIO_SERIAL generates?
>>>>          
>>>   We don't address this problem currently, maybe an integration with qdev
>>> will do, but I have to think more about it.
>>>        
>> So should I just keep it as VIRTIO_SERIAL for now? With new events also
>> riding on this one?
>>      
>   I don't like this because with the current events code this will lead
> to confusion, as you're using a single event to notify different things.
>
>   My suggestion for the immediate term is to do what we have been doing so
> far, ie. call it VIRTIO_SERIAL_ADD. Worst case here is: we add a new way
> to group events which requires a new VIRTIO_SERIAL event, in this case we
> could emit both, the new VIRTIO_SERIAL and the old VIRTIO_SERIAL_ADD. The
> latter would be deprecated too.
>
>   Or, if you can wait I can _try_ to solve this problem next week, although
> I have no idea how hard this is going to be.
>
>   Any comments, Anthony?
>    

The virtio serial events bother me in a number of ways.  Ports being 
added should just be more generic (we should generate an event any time 
a device is added to a bus).

Port disconnected/reconnect ought to be something that we propagate via 
a char device but I understand the limitations of the current code.

I'd like to see us try to at least address the add/remove case better 
and we may just have to live with the connect/disconnect stuff.

Regards,

Anthony Liguori