From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760487Ab0I1BZ6 (ORCPT ); Mon, 27 Sep 2010 21:25:58 -0400 Received: from mga09.intel.com ([134.134.136.24]:19169 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755983Ab0I1BZ4 convert rfc822-to-8bit (ORCPT ); Mon, 27 Sep 2010 21:25:56 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.57,244,1283756400"; d="scan'208";a="558531696" From: "Xin, Xiaohui" To: "Xin, Xiaohui" , "Michael S. Tsirkin" CC: "netdev@vger.kernel.org" , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "mingo@elte.hu" , "davem@davemloft.net" , "herbert@gondor.hengli.com.au" , "jdike@linux.intel.com" Date: Tue, 28 Sep 2010 09:25:46 +0800 Subject: RE: [PATCH v11 00/17] Provide a zero-copy method on KVM virtio-net. Thread-Topic: [PATCH v11 00/17] Provide a zero-copy method on KVM virtio-net. Thread-Index: ActdnV5IzY37EumUQUSR1zIrObvBqQAP3sEwADOC7uA= Message-ID: References: <1285388855-27410-1-git-send-email-xiaohui.xin@intel.com> <20100926170142.GA24196@redhat.com> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >-----Original Message----- >From: linux-kernel-owner@vger.kernel.org [mailto:linux-kernel-owner@vger.kernel.org] On >Behalf Of Xin, Xiaohui >Sent: Monday, September 27, 2010 8:45 AM >To: Michael S. Tsirkin >Cc: netdev@vger.kernel.org; kvm@vger.kernel.org; linux-kernel@vger.kernel.org; >mingo@elte.hu; davem@davemloft.net; herbert@gondor.hengli.com.au; >jdike@linux.intel.com >Subject: RE: [PATCH v11 00/17] Provide a zero-copy method on KVM virtio-net. > >>From: Michael S. Tsirkin [mailto:mst@redhat.com] >>Sent: Monday, September 27, 2010 1:02 AM >>To: Xin, Xiaohui >>Cc: netdev@vger.kernel.org; kvm@vger.kernel.org; linux-kernel@vger.kernel.org; >>mingo@elte.hu; davem@davemloft.net; herbert@gondor.hengli.com.au; >>jdike@linux.intel.com >>Subject: Re: [PATCH v11 00/17] Provide a zero-copy method on KVM virtio-net. >> >>On Sat, Sep 25, 2010 at 12:27:18PM +0800, xiaohui.xin@intel.com wrote: >>> We provide an zero-copy method which driver side may get external >>> buffers to DMA. Here external means driver don't use kernel space >>> to allocate skb buffers. Currently the external buffer can be from >>> guest virtio-net driver. >>> >>> The idea is simple, just to pin the guest VM user space and then >>> let host NIC driver has the chance to directly DMA to it. >>> The patches are based on vhost-net backend driver. We add a device >>> which provides proto_ops as sendmsg/recvmsg to vhost-net to >>> send/recv directly to/from the NIC driver. KVM guest who use the >>> vhost-net backend may bind any ethX interface in the host side to >>> get copyless data transfer thru guest virtio-net frontend. >>> patch 01-10: net core and kernel changes. >>> patch 11-13: new device as interface to mantpulate external buffers. >>> patch 14: for vhost-net. >>> patch 15: An example on modifying NIC driver to using napi_gro_frags(). >>> patch 16: An example how to get guest buffers based on driver >>> who using napi_gro_frags(). >>> patch 17: It's a patch to address comments from Michael S. Thirkin >>> to add 2 new ioctls in mp device. >>> We split it out here to make easier reiewer. >> >> >> >>I commented on how to avoid mm semaphore on data path separately, and >>since you didn't have time to review that yet, I won't repeat that here. >> > >I think I did avoid that in data path to use mm semaphore. I stored the value >in mp structures and check with that. > Hi Michael, Did you think I have addressed your comments about to avoid mm semaphore on data path or not? I stored the value in mp structures and don't use mmap_semphore. Or you still have some concerns with it? >>At this point what are the plans on macvtap integration? >>You indicated this is the interface you intend to use longterm. > >I'm now working on that. > I'm now trying to export some functions from mp device, and let macvtap to use them for rx zero-copy. > >Thanks >Xiaohui >-- >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/