From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46963) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YzNpx-00020Y-22 for qemu-devel@nongnu.org; Mon, 01 Jun 2015 07:24:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YzNpq-0002TE-KI for qemu-devel@nongnu.org; Mon, 01 Jun 2015 07:24:56 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57867) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YzNpq-0002Su-FK for qemu-devel@nongnu.org; Mon, 01 Jun 2015 07:24:50 -0400 Message-ID: <556C40FC.2060204@redhat.com> Date: Mon, 01 Jun 2015 13:24:44 +0200 From: Laszlo Ersek MIME-Version: 1.0 References: <1430320913-20737-1-git-send-email-somlo@cmu.edu> <1430320913-20737-5-git-send-email-somlo@cmu.edu> <20150531181048.GC5268@redhat.com> <556C046B.9070704@redhat.com> <20150601092645-mutt-send-email-mst@redhat.com> <556C1F63.1090605@redhat.com> <20150601121908-mutt-send-email-mst@redhat.com> <556C3757.7080603@redhat.com> In-Reply-To: <556C3757.7080603@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH V4 4/4] fw_cfg: insert fw_cfg file blobs via qemu cmdline List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini , "Michael S. Tsirkin" Cc: gsomlo@gmail.com, "Gabriel L. Somlo" , matt.fleming@intel.com, kraxel@redhat.com, qemu-devel@nongnu.org On 06/01/15 12:43, Paolo Bonzini wrote: > > > On 01/06/2015 12:23, Michael S. Tsirkin wrote: >> Still, reserving part of the namespace for QEMU internal use >> is *not* policy, it's just good engineering. >> >> How about we forbid adding files under "etc/" ? >> >> That would be enough to avoid conflicts. > > I do not understand. What we're doing is free-beer. We can always say > no. What's your worry? > > One usecase of this feature is to avoid recompiling QEMU while playing > with firmware. If you cannot mimic QEMU's behavior (which is to add > "etc/" files), the feature is pointless, or at least I totally cannot > understand its purpose and I'm against merging it. As far as I understand, the goal is indeed to expose fw_cfg to the host user, without having to recompile QEMU. This would allow site-specific fw_cfg files, for site-specific guest features. Gabriel wanted to control some guest-agent like functionality (on windows too) with it, IIRC. Matt Fleming @Intel might use it for custom OVMF development. I think those are valid goals and should be possible to support even if we isolate QEMU's own fw_cfg namespace strictly from the user (opt/) namespace. This feature is not there to mess with QEMU's "own" fw_cfg files; for those the existent command line switches should be used. Thanks Laszlo