From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965558AbXCENdP (ORCPT ); Mon, 5 Mar 2007 08:33:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965676AbXCENdP (ORCPT ); Mon, 5 Mar 2007 08:33:15 -0500 Received: from ozlabs.org ([203.10.76.45]:41794 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965558AbXCENdO (ORCPT ); Mon, 5 Mar 2007 08:33:14 -0500 Subject: Re: [patch] paravirt: VDSO page is essential From: Rusty Russell To: Avi Kivity Cc: Ingo Molnar , Andrew Morton , Linus Torvalds , linux-kernel@vger.kernel.org, Roland McGrath , Andi Kleen In-Reply-To: <45EC1472.3070208@qumranet.com> References: <20070305120631.GA14105@elte.hu> <45EC0EB7.7080300@qumranet.com> <20070305124024.GA19338@elte.hu> <45EC1472.3070208@qumranet.com> Content-Type: text/plain Date: Tue, 06 Mar 2007 00:32:14 +1100 Message-Id: <1173101534.26165.44.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.8.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2007-03-05 at 15:00 +0200, Avi Kivity wrote: > Ingo Molnar wrote: > > * Avi Kivity wrote: > > but yes, i agree that the hypervisor should have the ability to patch > > the syscall instruction of both the hypervisor interface and of the VDSO > > interface. But this wasnt implemented like that, and the #ifdef quirk > > just /prevents/ a sane solution like that from ever getting done the > > right way. > > > > Rusty, shouldn't this be a one-liner? No need to involve the hypervisor > here; the guest can s/syscall/int 80/ on its vdso page like it patches > cli and its ilk. Probably, but this is a red herring: see previous reply. Andi was a little overzealous w/ CONFIG_PARAVIRT & COMPAT_VDSO, that's all. I've never thought of replacing the syscall insn. I'll see if I can come up with a good reason to want to 8) Rusty.