From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Daniel P. Berrange" Subject: Re: [BUG] VM stuck in interrupt-loop after suspend to/resumed from file, or no interrupts at all Date: Wed, 12 Jan 2011 15:11:32 +0000 Message-ID: <20110112151132.GR26354@redhat.com> References: <201101121551.19083.hahn@univention.de> Reply-To: "Daniel P. Berrange" Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: kvm@vger.kernel.org To: Philipp Hahn Return-path: Received: from mx1.redhat.com ([209.132.183.28]:50116 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753744Ab1ALPLl (ORCPT ); Wed, 12 Jan 2011 10:11:41 -0500 Content-Disposition: inline In-Reply-To: <201101121551.19083.hahn@univention.de> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, Jan 12, 2011 at 03:51:13PM +0100, Philipp Hahn wrote: > Hello, > > libvirt implements a manages save, which suspens a VM to a file, from which it > can be resumed later. This uses Qemus/Kvms "migrate exec:" feature. > This doesn't work reliable for me: In may cases the resumed VM seems to be > stuck: its VNC console is restored, but no key presses or network packages > are accepted. This both happens with Windows XP, 7, 2008 and Linux 2.6.32 > systems. > > Using the debugging cycle described below in more detail I was able to track > the problem down to interrupt handling: Either the Linux-guest-kernel > constantly receives an interrupt for the 8139cp network adapter, or no > interrupts at all (neither network nor keyboard nor timer); only sending a > NMI works and shows that at least the Linux-Kernel is still alive. > > If I add the -no-kvm-irqchip Option, it seems to work; I was not able to > reproduce a hang. I remember reporting a bug with that scenario 4/5 months back and it being fixed in the host kernel IIRC. Daniel