Re: [Qemu-devel] [RFC PATCH] net: Enable vlans and dump for -netdev, too,

[Thomas Huth <thuth@redhat.com>]

On Tue, 26 May 2015 13:52:35 +0100
Stefan Hajnoczi <stefanha@redhat.com> wrote:

> On Fri, May 22, 2015 at 09:22:19PM +0200, Thomas Huth wrote:
> > So far, it is not possible to use the network dump interface
> > with the "-netdev" option yet, it only works with the legacy
> > "-net" option. To be able to use it with "-netdev", too, this
> > patch now enables the "vlan" packet distribution for the
> > "-netdev" option, too, so that you can now dump network packets
> > like this:
> > 
> > qemu... -device e1000,netdev=myhub -netdev hubport,hubid=1,id=myhub \
> >         -netdev user,id=n1,vlan=1,tftp=/tmp/tftp,bootfile=zImage \
> >         -netdev dump,id=n2,vlan=1,file=/tmp/dump.dat
> > 
> > Signed-off-by: Thomas Huth <thuth@redhat.com>
> > ---
> >  net/net.c        | 3 +++
> >  qapi-schema.json | 1 +
> >  2 files changed, 4 insertions(+)
> > 
> >  [Note: I'm quite new to this area of the code, please review carefully
> >   whether this approach makes sense or whether it should be done differently]
> 
> We thought the QEMU "vlan" concept would be dropped completely in the
> future, so it was never added to -netdev.  No patches to do that have
> been posted over the years, so I think it was more of a conceptual goal
> than a concrete requirement.
> 
> I'm okay with merging this but will leave some time for discussion
> before merging the patch.
> 
> "Speak now or forever hold your peace"

Certainly no objections from my side to keep this "vlan" concept in
QEMU, but thinking about this option again, I'd rather call it "hub=xx"
for the -netdev option instead of "vlan=xx", since this better matches
the "-netdev hubport" naming and it IMHO also describes the
functionality in a better way.
(of course I also need to add proper updates to the documentation files
in my patch in that way)

 Thomas