Re: [Qemu-devel] [PATCH v3 00/16] net: hub-based networking

[Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>]

On Fri, May 25, 2012 at 10:56:28AM -0300, Luiz Capitulino wrote:
> On Fri, 25 May 2012 15:47:28 +0200
> Paolo Bonzini <pbonzini@redhat.com> wrote:
> 
> > Il 25/05/2012 15:43, Luiz Capitulino ha scritto:
> > >> Yeah, VDE probably includes something like an hub.  But then we could
> > >> drop even "-net socket", "-net udp", "-net dump", and only leave in
> > >> vde+tap+slirp.  Or even move slirp into VDE. :)  That's a very different
> > >> thing.
> > > 
> > > Let's start with what is hurting us.
> > 
> > But is it?  The patch makes it quite clean.
> 
> vlan is and the cleanest solution is to drop it.

For the sake of the argument, here's what we'd need:

1. Patches to remove vlan completely from QEMU.
2. net/dump.c alternative.

Packet capture could be done like this:

  -netdev tap,dump=capture.pcap,...

You specify the "dump" option on a netdev giving a filename to use for
the pcap file.  The net/dump.c would need to be called from net.c or
maybe net/queue.c.

What we need to decide is whether it's okay to drop QEMU "VLANs"
completely and change dump command-line syntax?

I think vlan-hub doesn't hurt anyone because the code has been isolated
and we keep backwards compatibility.  So I'd personally still go the
vlan-hub route for QEMU 1.x.

Stefan