Re: [PATCH qemu-kvm] Add raw(af_packet) network backend to qemu

Arnd Bergmann
2010-01-27T09:34:50Z

On Wednesday 27 January 2010, Michael S. Tsirkin wrote:
> I am not sure I agree with this sentiment. The main issue being that
> macvtap doesn't exist on all kernels :). macvlan also requires hardware
> support, packet socket can work with any network card in promisc mode.

To be clear, macvlan does not require hardware support, it will happily
put cards into promiscous mode if they don't support multiple mac addresses.

> I agree to that. People don't even seem to agree whether it's a raw
> socket or a packet socket :) We need a better name for this option: what
> it really does is rely on an external device to loopback a packet to us,
> so how about -net loopback or -net extbridge?

I think -net socket,fd should just be (trivially) extended to work with raw
sockets out of the box, with no support for opening it. Then you can have
libvirt or some wrapper open a raw socket and a private namespace and just pass it
down. If you really want to let qemu open the socket itself, -net socket,raw=eth0
is probably closer to what you want than a new -net xxx option.

Arnd