From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1N5jJl-0002mZ-Ha for qemu-devel@nongnu.org; Wed, 04 Nov 2009 12:06:45 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1N5jJh-0002kO-J5 for qemu-devel@nongnu.org; Wed, 04 Nov 2009 12:06:45 -0500 Received: from [199.232.76.173] (port=56624 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1N5jJh-0002kH-7t for qemu-devel@nongnu.org; Wed, 04 Nov 2009 12:06:41 -0500 Received: from mx1.redhat.com ([209.132.183.28]:50638) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1N5jJg-0001O9-0p for qemu-devel@nongnu.org; Wed, 04 Nov 2009 12:06:40 -0500 Date: Wed, 4 Nov 2009 19:04:06 +0200 From: "Michael S. Tsirkin" Message-ID: <20091104170406.GA461@redhat.com> References: <1257294485-27015-1-git-send-email-aliguori@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1257294485-27015-1-git-send-email-aliguori@us.ibm.com> Subject: [Qemu-devel] Re: [PATCH 0/4] net-bridge: rootless bridge support for qemu List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: Mark McLoughlin , Arnd Bergmann , qemu-devel@nongnu.org, Juan Quintela , Dustin Kirkland 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