From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [RFCv2 00/12] Introduce host-side virtio queue and CAIF Virtio. Date: Fri, 11 Jan 2013 09:31:55 +0200 Message-ID: <20130111073155.GA13315@redhat.com> References: <871ug75vp1.fsf@rustcorp.com.au> <1354718230-4486-1-git-send-email-sjur@brendeland.net> <20121206102750.GF10837@redhat.com> <877goc0wac.fsf@rustcorp.com.au> <87pq1f2rj0.fsf@rustcorp.com.au> <87wqvl1g9s.fsf@rustcorp.com.au> <20130110111117.GE13451@redhat.com> <87sj681wou.fsf@rustcorp.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Sjur =?iso-8859-1?Q?Br=E6ndeland?= , Linus Walleij , virtualization@lists.linux-foundation.org, netdev@vger.kernel.org To: Rusty Russell Return-path: Received: from mx1.redhat.com ([209.132.183.28]:58460 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753168Ab3AKH2J (ORCPT ); Fri, 11 Jan 2013 02:28:09 -0500 Content-Disposition: inline In-Reply-To: <87sj681wou.fsf@rustcorp.com.au> Sender: netdev-owner@vger.kernel.org List-ID: On Fri, Jan 11, 2013 at 09:18:33AM +1030, Rusty Russell wrote: > "Michael S. Tsirkin" writes: > > On Thu, Jan 10, 2013 at 09:00:55PM +1030, Rusty Russell wrote: > >> Not sure why vhost/net doesn't built a packet and feed it in > >> netif_rx_ni(). This is what tun seems to do, and with this code it > >> should be fairly optimal. > > > > Because we want to use NAPI. > > Not quite what I was asking; it was more a question of why we're using a > raw socket, when we trivially have a complete skb already which we > should be able to feed to Linux like any network packet. > > And that path is pretty well optimized... > > Cheers, > Rusty. Oh for some reason I thought you were talking about virtio. I don't really understand what you are saying here - vhost actually calls out to tun to build and submit the skb. -- MST