From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44158) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eazeB-0004rT-KN for qemu-devel@nongnu.org; Mon, 15 Jan 2018 02:57:36 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eaze8-0004h3-JF for qemu-devel@nongnu.org; Mon, 15 Jan 2018 02:57:35 -0500 Received: from mga01.intel.com ([192.55.52.88]:30034) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eaze8-0004et-BX for qemu-devel@nongnu.org; Mon, 15 Jan 2018 02:57:32 -0500 Message-ID: <5A5C5F7D.8070403@intel.com> Date: Mon, 15 Jan 2018 15:59:57 +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> 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 01/15/2018 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 Vhost-pci solves the above issues by providing a point-to-point communication between VMs. No matter how the control path would look like finally, the key point is that the data path is P2P between VMs. Best, Wei