From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:60760) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QYi31-0001UU-Pd for qemu-devel@nongnu.org; Mon, 20 Jun 2011 13:14:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QYi2w-0004rP-Vv for qemu-devel@nongnu.org; Mon, 20 Jun 2011 13:14:03 -0400 Received: from david.siemens.de ([192.35.17.14]:21764) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QYi2w-0004qk-Db for qemu-devel@nongnu.org; Mon, 20 Jun 2011 13:13:58 -0400 Message-ID: <4DFF7FD0.4070002@siemens.com> Date: Mon, 20 Jun 2011 19:13:52 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <1308577094-17551-1-git-send-email-gollub@b1-systems.de> <20110620153825.GH13042@redhat.com> <4DFF6B20.7090107@redhat.com> <201106201826.32975.gollub@b1-systems.de> <4DFF76B1.8020509@redhat.com> In-Reply-To: <4DFF76B1.8020509@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 0/2] Introduce panic hypercall List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Avi Kivity Cc: Daniel Gollub , qemu-devel , kvm@vger.kernel.org On 2011-06-20 18:34, Avi Kivity wrote: >> > >> > Do ILO cards / IPMI support something like this? We could follow >> their >> > lead in that case. >> >> The only two things which came to my mind are: >> >> * NMI (aka. ipmitool diag) - already available in qemu/kvm - but >> requires >> in-guest kexec/kdump >> * Hardware-Watchdog (also available in qemu/libvirt) > > A watchdog has the advantage that is also detects lockups. > > In fact you could implement the panic device via the existing > watchdogs. Simply program the timer for the minimum interval and > *don't* service the interrupt. This would work for non-virt setups as > well as another way to issue a reset. If you manage to bring down the other guest CPUs fast enough. Otherwise, they may corrupt your crashdump before the host had a chance to collect all pieces. Synchronous signaling to the hypervisor is a bit safer. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux