From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46833) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YXmDb-0006HX-Ey for qemu-devel@nongnu.org; Tue, 17 Mar 2015 03:47:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YXmDY-0004HM-A4 for qemu-devel@nongnu.org; Tue, 17 Mar 2015 03:47:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55185) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YXmDY-0004HH-3T for qemu-devel@nongnu.org; Tue, 17 Mar 2015 03:47:12 -0400 Message-ID: <1426578418.27188.25.camel@nilsson.home.kraxel.org> From: Gerd Hoffmann Date: Tue, 17 Mar 2015 08:46:58 +0100 In-Reply-To: <20150316184145.GC1832@HEDWIG.INI.CMU.EDU> References: <1426515305-17766-1-git-send-email-somlo@cmu.edu> <1426515305-17766-3-git-send-email-somlo@cmu.edu> <55070CB5.6000003@redhat.com> <20150316184145.GC1832@HEDWIG.INI.CMU.EDU> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 2/6] fw_cfg: remove support for guest-side data writes List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Gabriel L. Somlo" Cc: matt.fleming@intel.com, mdroth@linux.vnet.ibm.com, rjones@redhat.com, jordan.l.justen@intel.com, "Gabriel L. Somlo" , qemu-devel@nongnu.org, gleb@cloudius-systems.com, pbonzini@redhat.com, Laszlo Ersek Hi, > Another possibility is to leave the write_ops in there, but turn them > into no-ops. That is the safe choice. Just have a write function with /* nothing, write support removed in qemu 2.4+ */. That is basically the same we have today (writes are ignored), but a bit more efficient because we kill the unused infrastructure to register writable fw_cfg entries and thus don't have to do the lookup just to figure there is no match ;) cheers, Gerd