From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [RFC] Virtual Machine Device Queues(VMDq) support on KVM Date: Tue, 22 Sep 2009 20:34:28 +0200 Message-ID: <200909222034.28865.arnd@arndb.de> References: <200909221350.54847.arnd@arndb.de> <20090922092957.17e68cbc@s6510> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: "Michael S. Tsirkin" , Chris Wright , Rusty Russell , virtualization@lists.linux-foundation.org, "Xin, Xiaohui" , "kvm@vger.kernel.org" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "hpa@zytor.com" , "mingo@elte.hu" , "akpm@linux-foundation.org" To: Stephen Hemminger Return-path: Received: from moutng.kundenserver.de ([212.227.126.186]:61255 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751107AbZIVSeu (ORCPT ); Tue, 22 Sep 2009 14:34:50 -0400 In-Reply-To: <20090922092957.17e68cbc@s6510> Sender: kvm-owner@vger.kernel.org List-ID: On Tuesday 22 September 2009, Stephen Hemminger wrote: > > My idea for that was to open multiple file descriptors to the same > > macvtap device and let the kernel figure out the right thing to > > do with that. You can do the same with raw packed sockets in case > > of vhost_net, but I wouldn't want to add more complexity to the > > tun/tap driver for this. > > > Or get tap out of the way entirely. The packets should not have > to go out to user space at all (see veth) How does veth relate to that, do you mean vhost_net? With vhost_net, you could still open multiple sockets, only the access is in the kernel. Obviously, once it all is in the kernel, that could be done under the covers, but I think it would be cleaner to treat vhost_net purely as a way to bypass the syscalls for user space, with as little as possible visible impact otherwise. Arnd <><