Re: [Qemu-devel] make qemu use tap0 instead of tun0

[Jim C. Brown]

On Wed, Jul 06, 2005 at 10:05:51PM -0400, Jim C. Brown wrote:
> I know this. Actually that page seems out of date, as Linux's tuntap now sends
> all accesses to /dev/net/tun regardless of the type of device (tun or tap).
> 

I should also add that on Linux, you can set the device name to what you want -
the requirement for tapX for tap devices and tunX for tun devices is not
enforced.

Note that for BSD, the function tun_open() in vl.c does open /dev/tap.

> The current NE2000 emulation (or any hardware nic emulation for that matter)
> would not work if qemu used an actual tun device.
> 

Ok this is not 100% true either. It wouldn't be too difficult to add a layer on
top of the nic hw emulation that did ethernet frame to ip frame and vice versa
before passing the frames to a tun device. (The user mode networking code
already does ethernet frame conversion.) So it wouldn't be that difficult to
get to work, and you wouldn't lose too much either (only IP-based protocols
such as TCP or UDP would work, but I've never heard of anyone trying to use
IPX or even IPv6 with qemu so that probably is not an issue).

-- 
Infinite complexity begets infinite beauty.
Infinite precision begets infinite perfection.