Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754922AbYFBUJh (ORCPT ); Mon, 2 Jun 2008 16:09:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752305AbYFBUJ1 (ORCPT ); Mon, 2 Jun 2008 16:09:27 -0400 Received: from smtp-outbound-1.vmware.com ([65.113.40.141]:49491 "EHLO smtp-outbound-1.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751516AbYFBUJ0 (ORCPT ); Mon, 2 Jun 2008 16:09:26 -0400 Subject: Re: [PATCH 0 of 4] mm+paravirt+xen: add pte read-modify-write abstraction From: Zachary Amsden To: Jeremy Fitzhardinge Cc: Ingo Molnar , LKML , xen-devel , Thomas Gleixner , Hugh Dickins , kvm-devel , Virtualization Mailing List , Rusty Russell , Peter Zijlstra , Linus Torvalds In-Reply-To: <48409847.4000902@goop.org> References: <1211567273.7465.36.camel@bodhitayantram.eng.vmware.com> <483729E7.9010002@goop.org> <1211585122.7465.70.camel@bodhitayantram.eng.vmware.com> <48409847.4000902@goop.org> Content-Type: text/plain Date: Mon, 02 Jun 2008 13:09:53 -0700 Message-Id: <1212437393.972.50.camel@bodhitayantram.eng.vmware.com> Mime-Version: 1.0 X-Mailer: Evolution 2.22.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1010 Lines: 20 On Sat, 2008-05-31 at 01:13 +0100, Jeremy Fitzhardinge wrote: > Zachary Amsden wrote: > > We don't fault. We write directly to the primary page tables, and clear > > the pte just like native. We just issue all mprotect updates in the > > queue, and flush the queue when leaving lazy mmu mode. You can't wait > > for the TLB flush, you must flush the updates before releasing the > > pagetable lock, or you could get misordered updates in an SMP system. > > > > How do you track which ptes need shadow updates? Do you walk the entire > pagetable on tlb flush? Or just rebuild the shadow from scratch on demand? No, we queue the updates as well as writing the primaries, we just flush the queue before dropping the PT lock for one trip to the hypervisor. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/