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

[Anthony Liguori]

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.
>
>