From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 834B6C433E0 for ; Mon, 18 Jan 2021 09:24:54 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EFB5F2222F for ; Mon, 18 Jan 2021 09:24:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EFB5F2222F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=antioche.eu.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.69488.124378 (Exim 4.92) (envelope-from ) id 1l1QmC-0005Ii-9T; Mon, 18 Jan 2021 09:24:44 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 69488.124378; Mon, 18 Jan 2021 09:24:44 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1l1QmC-0005Ib-6E; Mon, 18 Jan 2021 09:24:44 +0000 Received: by outflank-mailman (input) for mailman id 69488; Mon, 18 Jan 2021 09:24:42 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1l1QmA-0005I7-Fy for xen-devel@lists.xenproject.org; Mon, 18 Jan 2021 09:24:42 +0000 Received: from chassiron.antioche.eu.org (unknown [2001:41d0:fe9d:1101::1]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id ec63f5e7-02ca-424a-8d11-1956077a1999; Mon, 18 Jan 2021 09:24:41 +0000 (UTC) Received: from rochebonne.antioche.eu.org (rochebonne [IPv6:2001:41d0:fe9d:1100:221:70ff:fe0c:9885]) by chassiron.antioche.eu.org (8.15.2/8.15.2) with ESMTP id 10I9OYD8016356; Mon, 18 Jan 2021 10:24:34 +0100 (MET) Received: by rochebonne.antioche.eu.org (Postfix, from userid 1210) id 9ACE2281D; Mon, 18 Jan 2021 10:24:34 +0100 (CET) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: ec63f5e7-02ca-424a-8d11-1956077a1999 Date: Mon, 18 Jan 2021 10:24:34 +0100 From: Manuel Bouyer To: Roger Pau =?iso-8859-1?Q?Monn=E9?= Cc: xen-devel@lists.xenproject.org, Ian Jackson , Wei Liu , Anthony PERARD Subject: Re: [PATCH] libs/light: pass some infos to qemu Message-ID: <20210118092434.GC859@antioche.eu.org> References: <20210112181242.1570-1-bouyer@antioche.eu.org> <20210112181242.1570-17-bouyer@antioche.eu.org> <20210116101606.sogfpgzg7upunua7@Air-de-Roger> <20210116112502.GA1133@antioche.eu.org> <20210118083642.deozyeo5o6yziba7@Air-de-Roger> <20210118085214.GB859@antioche.eu.org> <20210118090722.jlf5j324mfeylp6t@Air-de-Roger> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210118090722.jlf5j324mfeylp6t@Air-de-Roger> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.4.3 (chassiron.antioche.eu.org [IPv6:2001:41d0:fe9d:1100:a00:20ff:fe1c:276e]); Mon, 18 Jan 2021 10:24:35 +0100 (MET) On Mon, Jan 18, 2021 at 10:07:22AM +0100, Roger Pau Monné wrote: > On Mon, Jan 18, 2021 at 09:52:14AM +0100, Manuel Bouyer wrote: > > On Mon, Jan 18, 2021 at 09:36:42AM +0100, Roger Pau Monné wrote: > > > I also wonder why NetBSD needs to add the tap interface to the bridge > > > in the QEMU script instead of doing it from the hotplug script called > > > by libxl, like Linux and FreeBSD do. > > > > the tap interface is created by qemu itself, its name is not known outside > > of qemu. Also, is there guarantee that qemu has created the tap before > > the hotplug script is called ? > > Yes, the toolstack will wait for QEMU to be initialized at which point > the tap interface has been created. > > I think I remember now why this didn't work on NetBSD. We ask QEMU to > create the tap interface with a specific name (using the vifname= > parameter), but NetBSD doesn't have the ioctl to rename network > interfaces implemented, and thus cannot rename the interface from tapX > to vifX.Y-emu, and hence you need to use the QEMU script from QEMU > itself because it's the only entity that knows the name of the tap > interface created. Yes; at some point I proposed to support name aliases to interface name in NetBSD but it got rejected ... so we have to use the name the kernel did choose for us. > > If you agree, can you add something along the lines to the commit > message? So that we remember why NetBSD needs to use the QEMU scripts. Will do. thanks -- Manuel Bouyer NetBSD: 26 ans d'experience feront toujours la difference --