From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-net 0/4] Increase the limit of tuntap queues Date: Sun, 23 Nov 2014 20:23:21 -0500 (EST) Message-ID: <20141123.202321.1426718936320546377.davem@davemloft.net> References: <20141123104623.GA31915@redhat.com> <20141123.134323.1154795102254868842.davem@davemloft.net> <20141123203032.GA6286@redhat.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: pagupta@redhat.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, jasowang@redhat.com, dgibson@redhat.com, vfalico@gmail.com, edumazet@google.com, vyasevic@redhat.com, hkchu@google.com, wuzhy@linux.vnet.ibm.com, xemul@parallels.com, therbert@google.com, bhutchings@solarflare.com, xii@google.com, stephen@networkplumber.org, jiri@resnulli.us, sergei.shtylyov@cogentembedded.com To: mst@redhat.com Return-path: In-Reply-To: <20141123203032.GA6286@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: "Michael S. Tsirkin" Date: Sun, 23 Nov 2014 22:30:32 +0200 > qemu runs in the host, but it's unpriveledged: it gets > passed tun FDs by a priveledged daemon, and it only > has the rights to some operations, > in particular to attach and detach queues. > > The assumption always was that this operation is safe > and can't make kernel run out of resources. This creates a rather rediculous situation in my opinion. Configuring a network device is a privileged operation, the daemon should be setting this thing up. In no other context would we have to worry about something like this.