From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH][RFC] pte notifiers -- support for external page tables Date: Wed, 05 Sep 2007 23:17:06 +0300 Message-ID: <46DF0EC2.7090408@qumranet.com> References: <11890207643068-git-send-email-avi@qumranet.com> <1189022183.10802.184.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, general-ZwoEplunGu1OwGhvXhtEPSCwEArCW2h5@public.gmane.org To: Rusty Russell Return-path: In-Reply-To: <1189022183.10802.184.camel-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Rusty Russell wrote: > On Wed, 2007-09-05 at 22:32 +0300, Avi Kivity wrote: > >> [resend due to bad alias expansion resulting in some recipients >> being bogus] >> >> Some hardware and software systems maintain page tables outside the normal >> Linux page tables, which reference userspace memory. This includes >> Infiniband, other RDMA-capable devices, and kvm (with a pending patch). >> > > And lguest. I can't tell until I've actually implemented it, but I > think it will seriously reduce the need for page pinning which is why > only root can currently launch guests. > > Ah yes, lguest. > My concern is locking: this is called with the page lock held, and I > guess we have to bump the guest out if it's currently running. > This will complicate kvm's locking too. We usually take kvm->lock to do mmu ops, but that is now a mutex. -- Any sufficiently difficult bug is indistinguishable from a feature. ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/