Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751221AbWHVT1J (ORCPT ); Tue, 22 Aug 2006 15:27:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751206AbWHVT1J (ORCPT ); Tue, 22 Aug 2006 15:27:09 -0400 Received: from mailout1.vmware.com ([65.113.40.130]:8395 "EHLO mailout1.vmware.com") by vger.kernel.org with ESMTP id S1751221AbWHVT0r (ORCPT ); Tue, 22 Aug 2006 15:26:47 -0400 Message-ID: <44EB5A76.9060402@vmware.com> Date: Tue, 22 Aug 2006 12:26:46 -0700 From: Zachary Amsden User-Agent: Thunderbird 1.5.0.5 (X11/20060719) MIME-Version: 1.0 To: Zachary Amsden , Alan Cox Cc: Arjan van de Ven , Andi Kleen , virtualization@lists.osdl.org, Jeremy Fitzhardinge , Andrew Morton , Chris Wright , Linux Kernel Mailing List Subject: Re: [PATCH] paravirt.h References: <1155202505.18420.5.camel@localhost.localdomain> <44DB7596.6010503@goop.org> <1156254965.27114.17.camel@localhost.localdomain> <200608221544.26989.ak@muc.de> <44EB3BF0.3040805@vmware.com> <1156271386.2976.102.camel@laptopd505.fenrus.org> <1156275004.27114.34.camel@localhost.localdomain> <44EB584A.5070505@vmware.com> In-Reply-To: <44EB584A.5070505@vmware.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 999 Lines: 24 Zachary Amsden wrote: > I've already implemented the locking and repatching bits for VMI. Incorrectly, I might add. The problem case for syscall patching is what do you do if there are in-service system calls? The comparable problem here is what if you interrupt code running in the old paravirt-ops, or worse, a section of code that you repatch when you do the switch? That is a really nasty problem. You need a synchronization primitive which guarantees a flat stack, so you can't do it in the interrupt handler as I have tried to do. I'll bang my head on it awhile. In the meantime, were there ever any solutions to the syscall patching problem that might lend me a clue as to what to do (or not to do, or impossible?). Thanks, Zach - 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/