From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42778) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VCQNA-000215-Iv for qemu-devel@nongnu.org; Thu, 22 Aug 2013 04:36:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VCQN4-0004xn-BY for qemu-devel@nongnu.org; Thu, 22 Aug 2013 04:36:04 -0400 Message-ID: <5215CDFB.7000201@redhat.com> Date: Thu, 22 Aug 2013 10:38:19 +0200 From: Laszlo Ersek MIME-Version: 1.0 References: <1377086477-19553-1-git-send-email-pbonzini@redhat.com> <5214DB87.6010305@redhat.com> <5214DD8B.2020803@redhat.com> In-Reply-To: <5214DD8B.2020803@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] vl: allow "cont" from panicked state List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: pkrempa@redhat.com, marcel.a@redhat.com, libvir-list@redhat.com, hutao@cn.fujitsu.com, qemu-stable@nongnu.org, mst@redhat.com, qemu-devel@nongnu.org, lcapitulino@redhat.com, rhod@redhat.com, kraxel@redhat.com, anthony@codemonkey.ws, afaerber@suse.de On 08/21/13 17:32, Paolo Bonzini wrote: > To support 1.5, libvirt should simply be ready to react to unanticipated > GUEST_PANICKED events. reboot-on-panic will simply be broken for 1.5 > and Linux 3.10+ guests. :( I'm probably misunderstanding the discussion, but it might be possible to disable pvpanic even in 1.5 from the host side, with the following hack: -global pvpanic.ioport=0 In qemu, this will either configure a working pvpanic device on ioport 0, or the pvpanic device will be genuinely broken. At least it doesn't (obviously) break other stuff (in v1.5.2): (qemu) info mtree I/O 0000000000000000-000000000000ffff (prio 0, RW): io 0000000000000000-0000000000000000 (prio 0, RW): pvpanic 0000000000000000-0000000000000007 (prio 0, RW): dma-chan (qemu) info qtree bus: main-system-bus dev: i440FX-pcihost, id "" bus: pci.0 dev: PIIX3, id "" bus: isa.0 dev: pvpanic, id "" ioport = 0 Either way, the "etc/pvpanic-port" fw_cfg file will contain 0, and SeaBIOS will interpret it as "no pvpanic device". It will report the same to the Linux guest too (_STA will return 0 for QEMU0001; pvpanic_add() --> -ENODEV). Thus, no pvpanic notifier should be registered, and reboot-on-panic should be reachable in the guest. A horrible hack, certainly. Laszlo