Re: [Qemu-devel] [patch] Linux TUN/TAP driver updates

[Henrik Nordstrom]

On Sun, 18 Sep 2005, Felix Lechner wrote:

> Apparently I have the same desire to use a persistent tap0 device with
> qemu like you did in April.  I can configure tap0 with tunctl and
> standard debian networking, but passing that information to qemu is a
> riddle to me.

Attached is my patch relative the current CVS.

This patch adds the -tun-dev command line option

  -tun-dev name

specifying the TUN/TAP device name to attach to.

In addition the patch fixes the existing -tun-fd option allowing it to be 
specified multiple times if desired.

> Your patch never made it into version 7.2 (and it does not apply without 
> errors anymore) which makes me think there is another way to do it.

No, just not many doing this it seems.

> Like everybody else, I also thought about a little program similar to
> Russell's tundev that opens the interface and passes the fd via command
> line option -tun-fd.

To qemu there is no real difference.

However, without patching the -tun-fd option is limited to a single 
interface due to a name collision on the internal qemu device name.

> What's the right way to do this?

The current configuration options have quite many shortcomings. There is 
discussion about rearranging the networking options making configuration 
more sane

   - TUN/TAP devices
   - TUN/TAP file descriptors
   - MAC addresses
   - user-net
   - etc..

There is a very nice proposal by Fabrice on how he likes the command line 
to look like making configuration quite sane and flexible, what remains is 
for someone to implement this.

http://lists.gnu.org/archive/html/qemu-devel/2005-08/msg00196.html

Regards
Henrik

qemu-tuntap.patch
Description: Text document