From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49525) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V8XOT-0002TS-Ra for qemu-devel@nongnu.org; Sun, 11 Aug 2013 11:17:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V8XOH-00031V-Ur for qemu-devel@nongnu.org; Sun, 11 Aug 2013 11:17:21 -0400 Received: from mail-ee0-x229.google.com ([2a00:1450:4013:c00::229]:34010) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V8XOH-00031Q-O6 for qemu-devel@nongnu.org; Sun, 11 Aug 2013 11:17:09 -0400 Received: by mail-ee0-f41.google.com with SMTP id d17so3002637eek.14 for ; Sun, 11 Aug 2013 08:17:08 -0700 (PDT) Message-ID: <1376234212.2083.14.camel@localhost.localdomain> From: Marcel Apfelbaum Date: Sun, 11 Aug 2013 18:16:52 +0300 In-Reply-To: <5207A36F.2050308@suse.de> References: <1375362537.4891.28.camel@localhost.localdomain> <1375427079-16822-1-git-send-email-hutao@cn.fujitsu.com> <51FB6D73.9090902@redhat.com> <20130811103341.GA13848@redhat.com> <5207A36F.2050308@suse.de> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH for-1.6 1/2] don't create pvpanic device by default. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Andreas =?ISO-8859-1?Q?F=E4rber?= Cc: Paolo Bonzini , Hu Tao , qemu-devel@nongnu.org, "Michael S. Tsirkin" On Sun, 2013-08-11 at 16:45 +0200, Andreas Färber wrote: > Am 11.08.2013 12:33, schrieb Michael S. Tsirkin: > > On Fri, Aug 02, 2013 at 10:27:31AM +0200, Paolo Bonzini wrote: > >> On 08/02/2013 09:04 AM, Hu Tao wrote: > >>> The problem with pvpanic being an internal device is that VMs running > >>> operating systems without a driver for this device will have problems > >>> when qemu will be upgraded (from qemu without this pvpanic). > >>> > >>> The outcome may be, for example: in Windows(let's say XP) the Device > >>> manager will open a "new device" wizard and the device will appear as > >>> an unrecognized device. On a cluster with hundreds of such VMs, If > >>> that cluster has a health monitoring service it may show all the VMs > >>> in a "not healthy" state. > >>> > >>> Reported-by: Marcel Apfelbaum > >>> Signed-off-by: Hu Tao > >> > >> NACK, > >> > >> this is premature. It is fundamentally a firmware problem. > >> > >> We have time to apply an even smaller patch that doesn't set > >> has_pvpanic to true, and delay the whole feature to 1.7, if we do > >> not fix the firmware in the next two weeks. > >> > >> Paolo > > > > I think this is not just a firmware problem. Adding device by default > > was too rush, assumption was risk of guest bugs was 0. > > > > We are now seeing problems with bios guest code and with linux guest > > drivers as well. Yes they all can be fixed, but we simply shouldn't > > force this risk of broken guests on everyone. > > > > libvirt is the main user and libvirt people > > indicated their preference to creating device with > > -device pvpanic rather than a built-in one that > > can't be removed. > > > > So please reconsider, and here's an ack from me. > > > > Acked-by: Michael S. Tsirkin > > NACK for this v1: As pointed out on the KVM call, we still need to keep > the pvpanic device around by default for pc-*-1.5. Removing has_pvpanic > completely therefore seems wrong. Can you submit a v2 for rc3 tomorrow? I just sent a patchset with V2. Can you please review it? Thanks, Marcel > > Andreas >