From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46776) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ebjId-0004xn-EA for qemu-devel@nongnu.org; Wed, 17 Jan 2018 03:42:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ebjIa-0007Ro-7b for qemu-devel@nongnu.org; Wed, 17 Jan 2018 03:42:23 -0500 Received: from mga04.intel.com ([192.55.52.120]:53107) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ebjIZ-0007RE-VR for qemu-devel@nongnu.org; Wed, 17 Jan 2018 03:42:20 -0500 Message-ID: <5A5F0CFD.5030204@intel.com> Date: Wed, 17 Jan 2018 16:44:45 +0800 From: Wei Wang MIME-Version: 1.0 References: <20180110161438.GA28096@stefanha-x1.localdomain> <20180111152345.GA7353@stefanha-x1.localdomain> <86106573-422b-fe4c-ec15-dad0edf05880@redhat.com> <20180112101807.GE7356@stefanha-x1.localdomain> <5A5C5F7D.8070403@intel.com> <6b618d06-0891-fb3b-b845-8beae5649b22@redhat.com> <5A5C85DD.10705@intel.com> In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] vhost-pci and virtio-vhost-user List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jason Wang , Stefan Hajnoczi Cc: qemu-devel@nongnu.org On 01/16/2018 01:33 PM, Jason Wang wrote: > > > On 2018年01月15日 18:43, Wei Wang wrote: >> On 01/15/2018 04:34 PM, Jason Wang wrote: >>> >>> >>> On 2018年01月15日 15:59, Wei Wang wrote: >>>> On 01/15/2018 02:56 PM, Jason Wang wrote: >>>>> >>>>> >>>>> On 2018年01月12日 18:18, Stefan Hajnoczi wrote: >>>>>> >>>>> >>>>> I just fail understand why we can't do software defined network or >>>>> storage with exist virtio device/drivers (or are there any >>>>> shortcomings that force us to invent new infrastructure). >>>>> >>>> >>>> Existing virtio-net works with a host central vSwitch, and it has >>>> the following disadvantages: >>>> 1) long code/data path; >>>> 2) poor scalability; and >>>> 3) host CPU sacrifice >>> >>> Please show me the numbers. >> >> Sure. For 64B packet transmission between two VMs: vhost-user reports >> ~6.8Mpps, and vhost-pci reports ~11Mpps, which is ~1.62x faster. >> > > This result is kind of incomplete. So still many questions left: > > - What's the configuration of the vhost-user? > - What's the result of e.g 1500 byte? > - You said it improves scalability, at least I can't get this > conclusion just from what you provide here > - You suspect long code/data path, but no latency numbers to prove it > Had an offline meeting with Jason. The future discussion will be more focused on the design. Here is a conclusion about more results we collected for 64B packet transmission, compared to ovs-dpdk (though we are comparing to ovs-dpdk here, but vhost-pci isn't meant to replace ovs-dpdk. It's for inter-VM communication, and packets going to the outside world will go from the traditional backend like ovs-dpdk): 1) 2VM communication: over 1.6x higher throughput; 2) 22% shorter latency; 3) in the 5-VM chain communication tests, vhost-pci shows ~6.5x higher throughput thanks to its better scalability We'll provide 1500B test results later. Best, Wei