[Qemu-devel] Re: [PATCH 0/4] net-bridge: rootless bridge support for qemu

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Nov 03, 2009 at 06:28:01PM -0600, Anthony Liguori wrote:
> This series solves a problem that I've been struggling with for a few years now.
> One of the best things about qemu is that it's possible to run guests as an
> unprivileged user to improve security.  However, if you want to have your guests
> communicate with the outside world, you're pretty much forced to run qemu as
> root.
> 
> At least with KVM support, this is probably the most common use case which means
> that most of our users are running qemu as root.  That's terrible.
> 
> We address this problem by introducing a new network backend: -net bridge.  This
> backend is less flexible than -net tap because it relies on a helper with
> elevated privileges to do the heavy lifting of allocating and attaching a tap
> device to a bridge.  We use a special purpose helper because we don't want
> to elevate the privileges of more generic tools like brctl.
> 
> >From a user perspective, to use bridged networking with a guest, you simply use:
> 
>   qemu -hda linux.img -net bridge -net nic
> 
> And assuming a bridge is defined named qemubr0 and the administrator has setup
> permissions accordingly, it will Just Work.  My hope is that distributions will
> do this work as part of the qemu packaging process such that for most users,
> the out-of-the-box experience will also Just Work.
> 
> More details are included in individual patches.  I broke up the helper into
> a series of patches to improve reviewabilty.

Would raw backend attached to a bridge mostly do the same?

-- 
MST