From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1N5m8G-0000Dh-PV for qemu-devel@nongnu.org; Wed, 04 Nov 2009 15:07:04 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1N5m8C-0000Cb-7H for qemu-devel@nongnu.org; Wed, 04 Nov 2009 15:07:04 -0500 Received: from [199.232.76.173] (port=58214 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1N5m8C-0000CY-0a for qemu-devel@nongnu.org; Wed, 04 Nov 2009 15:07:00 -0500 Received: from mx1.redhat.com ([209.132.183.28]:17091) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1N5m8B-0007LI-Fj for qemu-devel@nongnu.org; Wed, 04 Nov 2009 15:06:59 -0500 Date: Wed, 4 Nov 2009 22:04:23 +0200 From: "Michael S. Tsirkin" Subject: Re: [Qemu-devel] Re: [PATCH 0/4] net-bridge: rootless bridge support for qemu Message-ID: <20091104200423.GA935@redhat.com> References: <1257294485-27015-1-git-send-email-aliguori@us.ibm.com> <20091104170406.GA461@redhat.com> <4AF1DA71.2000209@codemonkey.ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4AF1DA71.2000209@codemonkey.ws> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: Mark McLoughlin , Arnd Bergmann , Dustin Kirkland , qemu-devel@nongnu.org, Juan Quintela On Wed, Nov 04, 2009 at 01:48:01PM -0600, Anthony Liguori wrote: > Michael S. Tsirkin wrote: >> 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? >> > > Well it doesn't really help with the issue of privileges which is what > this series is really about. > > Regards, > > Anthony Liguori I note that by default you grant all users all access. If you do that, just give them net cap admin already? -- MST