From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754301Ab0INRCf (ORCPT ); Tue, 14 Sep 2010 13:02:35 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.145]:53495 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751967Ab0INRCd (ORCPT ); Tue, 14 Sep 2010 13:02:33 -0400 Subject: Re: [RFC PATCH 2/2] macvtap: TX zero copy between guest and host kernel From: Shirley Ma To: "Michael S. Tsirkin" Cc: Arnd Bergmann , Avi Kivity , "Xin, Xiaohui" , David Miller , netdev@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20100914162952.GB13560@redhat.com> References: <1284410580.13351.10.camel@localhost.localdomain> <4C8F3C77.7010302@redhat.com> <1284476719.13351.35.camel@localhost.localdomain> <201009141721.13202.arnd@arndb.de> <20100914152231.GA13105@redhat.com> <1284480025.13351.49.camel@localhost.localdomain> <20100914162952.GB13560@redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Tue, 14 Sep 2010 10:02:25 -0700 Message-ID: <1284483745.13351.71.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 (2.28.3-1.fc12) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2010-09-14 at 18:29 +0200, Michael S. Tsirkin wrote: > Precisely. This is what the patch from Xin Xiaohui does. That code > already seems to do most of what you are trying to do, right? I thought host pins guest kernel buffer pages was good enough for TX thought I didn't look up xiaohui's vhost asycn io patch in details. What's the performance data Xiaohui got from using kiocb? I haven't seen any performance number from him yet. > The main thing missing seems to be macvtap integration, so that we can > fall back > on data copy if zero copy is unavailable? > How hard would it be to basically link the mp and macvtap modules > together to get us this functionality? Anyone? The simple integration is using macvtap + xiaohui's vhost asycn io patch. I can make a try for TX only. Thanks Shirley