From mboxrd@z Thu Jan 1 00:00:00 1970 From: jiangyiwen Subject: Re: [RFC] Discuss about an new idea "Vsock over Virtio-net" Date: Tue, 4 Dec 2018 10:21:40 +0800 Message-ID: <5C05E4B4.3040804@huawei.com> References: <5BECEE53.7090408@huawei.com> <20181115015547-mutt-send-email-mst@kernel.org> <61d57505-7ff6-23c6-d26c-6a0062e08445@redhat.com> <20181129085049-mutt-send-email-mst@kernel.org> <7e78fc3d-0d5a-090f-476d-03ad490ff8a2@redhat.com> <20181130075134-mutt-send-email-mst@kernel.org> <55352308-9ceb-413e-44f6-e3dfd8f642cc@redhat.com> <27cd8ac6-e892-cfaa-cd39-74f39b452681@redhat.com> <20181130083540-mutt-send-email-mst@kernel.org> <5C049EC2.3080002@huawei.com> <20181203202441-mutt-send-email-mst@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Cc: Jason Wang , , , , , To: "Michael S. Tsirkin" Return-path: Received: from szxga04-in.huawei.com ([45.249.212.190]:16076 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725937AbeLDCVr (ORCPT ); Mon, 3 Dec 2018 21:21:47 -0500 In-Reply-To: <20181203202441-mutt-send-email-mst@kernel.org> Sender: netdev-owner@vger.kernel.org List-ID: On 2018/12/4 9:31, Michael S. Tsirkin wrote: > On Mon, Dec 03, 2018 at 11:10:58AM +0800, jiangyiwen wrote: >> On 2018/11/30 21:40, Michael S. Tsirkin wrote: >>> On Fri, Nov 30, 2018 at 09:10:03PM +0800, Jason Wang wrote: >>>> >>>> On 2018/11/30 下午8:55, Jason Wang wrote: >>>>> >>>>> On 2018/11/30 下午8:52, Michael S. Tsirkin wrote: >>>>>>>> If you want to compare it with >>>>>>>> something that would be TCP or QUIC. The fundamental >>>>>>>> difference between >>>>>>>> virtio-vsock and e.g. TCP is that TCP operates in a packet >>>>>>>> loss environment. >>>>>>>> So they are using timers for reliability, and receiver is >>>>>>>> always free to >>>>>>>> discard any unacked data. >>>>>>> Virtio-net knows nothing above L2, so they are totally >>>>>>> transparent to device >>>>>>> itself. I still don't get why not using virtio-net instead. >>>>>>> >>>>>>> >>>>>>> Thanks >>>>>> Is your question why is virtio-vsock used instead of TCP on top of IP >>>>>> on top of virtio-net? >>>>>> >>>>>> >>>>> >>>>> No, my question is why not do vsock through virtio-net. >>>>> >>>>> Thanks >>>>> >>>> >>>> Just to clarify, it's not about vosck over ethernet, and it's not about >>>> inventing new features or APIs. It's probably something like: >>>> >>>> - Let virtio-net driver probe vsock device and do vosck specific things if >>>> needed to share as much codes. >>>> >>>> - A new kind of sockfd (which is vsock based) for vhost-net for it to do >>>> vsock specific things (hopefully it can be transparent). >>>> >>>> The change should be totally transparent to userspace applications. >>>> >>>> Thanks >>> >>> Which code is duplicated between virtio vsock and virtio net right now? >>> >> >> Hi Michael, >> >> AFAIK, there is almost no duplicate code between virtio vsock and virtio net now. >> >> But, if virtio vsock wants to support mergeable rx buffer and multiqueue feature, >> it has some duplicate codes from virtio net. Based on it, we both think vsock >> may use virtio net as a transport channel, in this way, vsock can use some of >> virtio net great features. >> >> Thanks, >> Yiwen. > > What I would do is just copy some code and show a performance > benefit. If that works out it will be clearer which code > should be shared. > Hi Michael, I have already sent a series of patches (VSOCK: support mergeable rx buffer in vhost-vsock) a month ago, and the performance as follows: I write a tool to test the vhost-vsock performance, mainly send big packet(64K) included guest->Host and Host->Guest. The result as follows: Before performance: Single socket Multiple sockets(Max Bandwidth) Guest->Host ~400MB/s ~480MB/s Host->Guest ~1450MB/s ~1600MB/s After performance: Single socket Multiple sockets(Max Bandwidth) Guest->Host ~1700MB/s ~2900MB/s Host->Guest ~1700MB/s ~2900MB/s >>From the test results, the performance is improved obviously, and guest memory will not be wasted. In addition, multiqueue feature I have not implemented it yet. Thanks, Yiwen.