From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:38177)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1VCBdh-0006tH-A4
	for qemu-devel@nongnu.org; Wed, 21 Aug 2013 12:52:16 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1VCBdb-0006ey-Ah
	for qemu-devel@nongnu.org; Wed, 21 Aug 2013 12:52:09 -0400
Received: from mx1.redhat.com ([209.132.183.28]:57709)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <pbonzini@redhat.com>) id 1VCBdb-0006eu-2V
	for qemu-devel@nongnu.org; Wed, 21 Aug 2013 12:52:03 -0400
Message-ID: <5214EFFF.3060804@redhat.com>
Date: Wed, 21 Aug 2013 18:51:11 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
MIME-Version: 1.0
References: <1377103396-24307-1-git-send-email-pbonzini@redhat.com>
	<20130821164817.GC10012@redhat.com>
In-Reply-To: <20130821164817.GC10012@redhat.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [RFC PATCH v2 0/3] Start fixing the pvpanic mess
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: "Daniel P. Berrange" <berrange@redhat.com>
Cc: pkrempa@redhat.com, marcel.a@redhat.com, libvir-list@redhat.com, lersek@redhat.com, mst@redhat.com, qemu-devel@nongnu.org, armbru@redhat.com, rhod@redhat.com, kraxel@redhat.com, anthony@codemonkey.ws, hutao@cn.fujitsu.com, lcapitulino@redhat.com, afaerber@suse.de

Il 21/08/2013 18:48, Daniel P. Berrange ha scritto:
> No, <on_crash> is the right thing to be using for this from
> libvirt's pov & I don't think we should invent something new.
> The <on_crash> element has always been intended to represent
> handling of guest panics, not qemu internal errors.

Actually for Xen HVM guests, it mostly traps things such as failed
vmentries.  The Xen PV-on-HVM drivers do not register a panic notifier
that moves the guest to the "crashed" state.

<on_crash> cannot be salvaged, in my opinion, because all domain XMLs in
the wild will have a setting that causes libvirt to add "-device
isa-pvpanic".  Thus changing libvirt versions will change guest
hardware, which is _very_ bad.

In addition, Windows XP and 2003 will show the annoying device wizard
upon a libvirt upgrade, and fixing this is what surfaced all the mess.

Paolo