Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756597AbXH1G6L (ORCPT ); Tue, 28 Aug 2007 02:58:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751456AbXH1G56 (ORCPT ); Tue, 28 Aug 2007 02:57:58 -0400 Received: from smtp-outbound-1.vmware.com ([65.113.40.141]:48900 "EHLO smtp-outbound-1.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751426AbXH1G55 (ORCPT ); Tue, 28 Aug 2007 02:57:57 -0400 Message-ID: <46D3C60B.3050605@vmware.com> Date: Mon, 27 Aug 2007 23:51:55 -0700 From: Zachary Amsden User-Agent: Thunderbird 2.0.0.6 (X11/20070728) MIME-Version: 1.0 To: Benjamin Herrenschmidt CC: Rusty Russell , Avi Kivity , Andrew Morton , Linux Kernel Mailing List , Virtualization Mailing List , Chris Wright , Jeremy Fitzhardinge Subject: Re: [PATCH] Add I/O hypercalls for i386 paravirt References: <46CBC842.4070100@vmware.com> <46CBCADF.2070400@qumranet.com> <1187763956.6174.48.camel@localhost.localdomain> <1188237281.5972.69.camel@localhost.localdomain> In-Reply-To: <1188237281.5972.69.camel@localhost.localdomain> 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: 1283 Lines: 36 Benjamin Herrenschmidt wrote: > On Wed, 2007-08-22 at 16:25 +1000, Rusty Russell wrote: > >> On Wed, 2007-08-22 at 08:34 +0300, Avi Kivity wrote: >> >>> Zachary Amsden wrote: >>> >>>> This patch provides hypercalls for the i386 port I/O instructions, >>>> which vastly helps guests which use native-style drivers. For certain >>>> VMI workloads, this provides a performance boost of up to 30%. We >>>> expect KVM and lguest to be able to achieve similar gains on I/O >>>> intensive workloads. >>>> >>> Won't these workloads be better off using paravirtualized drivers? >>> i.e., do the native drivers with paravirt I/O instructions get anywhere >>> near the performance of paravirt drivers? >>> >> This patch also means I can kill off the emulation code in >> drivers/lguest/core.c, which is a real relief. >> > > Hrm... how do you deal with X doing IOs ? > > Ben. > We have an X driver that does minimal performance costing operations. As we should and will have for our other drivers. 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/