From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [kvm-devel] [PATCH][RFC] pte notifiers -- support for external page tables From: Rusty Russell In-Reply-To: <11890207643068-git-send-email-avi@qumranet.com> References: <11890207643068-git-send-email-avi@qumranet.com> Content-Type: text/plain Date: Thu, 06 Sep 2007 05:56:23 +1000 Message-Id: <1189022183.10802.184.camel@localhost.localdomain> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Avi Kivity Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, kvm-devel@lists.sourceforge.net, general@lists.openfabrics.org List-ID: 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. 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. (Oh, and this means lguest needs to do a reverse mapping somehow, but I'll come up with something). Cheers, Rusty. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org