Re: [Qemu-devel] [PATCH] configure: add an option to disable vlans

[Anthony Liguori <anthony@codemonkey.ws>]

On 06/08/2010 07:13 AM, Michael S. Tsirkin wrote:
> On Mon, Jun 07, 2010 at 04:57:09PM -0500, Anthony Liguori wrote:
>    
>> On 06/07/2010 04:37 PM, Anthony Liguori wrote:
>>      
>>> On 06/07/2010 03:58 PM, Michael S. Tsirkin wrote:
>>>        
>>>> On Mon, Jun 07, 2010 at 03:40:57PM -0500, Anthony Liguori wrote:
>>>>          
>>>>> On 06/07/2010 02:21 PM, Michael S. Tsirkin wrote:
>>>>>            
>>>>>> So I see two ways to go forward: switch default value in my patch,
>>>>>> or disable vlans unconditionally.
>>>>>>
>>>>>>              
>>>>> The problem with disabling vlans unconditionally is that you break -net
>>>>> socket and -net dump.
>>>>>
>>>>> If we can come up with an alternative way to do these things, I'm all
>>>>> for removing it.
>>>>>            
>>>> Hmm, I'll try to look at supporting -net socket in netdev.
>>>> Does -net dump do anything that can't be done with tap+tcpdump?
>>>>          
>>> tap+tcpdump requires root privileges (even if you have a tap helper).
>>>
>>> Plus tcpdump doesn't help with slirp and -net dump is very useful for
>>> debugging slirp.
>>>        
> Developer's need for root access for debugging seems a reasonable price to
> pay to prevent user confusion and complexity that we have now.
>    

Removing vlans has the potential to break existing deployments.  That's 
something we need to do very cautiously.

What do we gain from removing vlan support today?

Regards,

Anthony Liguori

>> Of course, you could add this functionality to netdev.  It's arguably
>> better there too because then you can debug virtio-net+tap with full
>> offload enabled (which you cannot do today).
>>
>> Regards,
>>
>> Anthony Liguori
>>      
> Care taking on it? I never even heard about -net dump before today.
>
>