[Qemu-devel] Re: [PATCH 9/9] Introduce VLANClientState::cleanup()

[Anthony Liguori <aliguori@us.ibm.com>]

Blue Swirl wrote:
> On 4/30/09, Anthony Liguori <aliguori@us.ibm.com> wrote:
>   
>> Jan Kiszka wrote:
>>
>>     
>>> That would only allow one such pair per VM.
>>>
>>>
>>>       
>>  id basically becomes another type of vlan id.  To have multiple nics, you
>> do:
>>
>>  -net tap,vlan=off,id=1234 -net
>> nic,model=virtio,vlan=off,id=1234
>>  -net tap,vlan=off,id=4321 -net
>> nic,model=virtio,vlan=off,id=4321
>>     
>
> I think "off" and "id" are not descriptive enough, how about:
>  -net tap,vlan=pointopoint,ptop_id=4321 -net
> nic,model=virtio,vlan=pointopoint,ptop_id=4321
>   

or vlan=none?  p2p doesn't make very much sense to me personally.

I agree "id" may be too generic.  Maybe devid or device_id?

>>  I think you're suggesting the same thing as me, except you are saying make
>> vlan=off implicit, and use vlan=XXX instead of id=XXX.
>>
>>  We can still make vlan=off implicit, and default id=0, so that -net tap net
>> nic,model=virtio does the right thing.  However, if a user explicitly says
>> -net tap,vlan=1 -net nic,model=virtio,vlan=1, it behaves like it used to.
>>     
>
> Nice, though if there are two vlans, one specified without explicit ID
> and the other with ID=1, the performance will be different.
>   

If a user mixes vlans and p2p links, then yeah, performance is going to 
be different.  I'd like to eventually make vlan=none the default to be 
perfectly honest.  I don't think many people depend on implicit vlan=0 
so I don't think we'll really break anyone.

-- 
Regards,

Anthony Liguori