From mboxrd@z Thu Jan 1 00:00:00 1970 From: Charles Duffy Subject: Re: kvm-78 - kernel panic after using system_reset except when using -no-kvm-irqchip Date: Wed, 12 Nov 2008 12:10:36 -0600 Message-ID: References: <491A807F.20403@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit To: kvm@vger.kernel.org Return-path: Received: from main.gmane.org ([80.91.229.2]:35790 "EHLO ciao.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751540AbYKLSKt (ORCPT ); Wed, 12 Nov 2008 13:10:49 -0500 Received: from list by ciao.gmane.org with local (Exim 4.43) id 1L0KAu-0008LN-Lo for kvm@vger.kernel.org; Wed, 12 Nov 2008 18:10:44 +0000 Received: from rrcs-71-41-149-67.sw.biz.rr.com ([71.41.149.67]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 12 Nov 2008 18:10:44 +0000 Received: from Charles_Duffy by rrcs-71-41-149-67.sw.biz.rr.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 12 Nov 2008 18:10:44 +0000 In-Reply-To: <491A807F.20403@web.de> Sender: kvm-owner@vger.kernel.org List-ID: Jan Kiszka wrote: > Charles Duffy wrote: >> irq 25, desc: ffffffff803afc80, depth: 1, count: 0, unhandled: 0 >> ->handle_irq(): ffffffff800b54e3, handle_bad_irq+0x0/0x1f6 >> ->chip(): ffffffff802ea700, 0xffffffff802ea700 >> ->action(): 0000000000000000 >> IRQ_DISABLED set >> unexpected IRQ trap at vector 19 >> ..MP-BIOS bug: 8254 timer not connected to IO-APIC >> timer doesn't work through the IO-APIC - disabling NMI Watchdog! >> Kernel panic - not syncing: IO-APIC + timer doesn't work! Try using the >> 'noapic' kernel parameter > > Still too early for me, so I didn't get yet if you can trigger this > guest panic reliably or only sporadically (like I can). In the former > case I would be very interested in the how! Reproduced 100% of the time when using system_reset at the qemu monitor console coming from a non-panic'd state. (Thus, it happens only every other time doing a series of boots and system_reset monitor commands). > So far my theory on this is that the guest happens to loose too many PIC > timer ticks during the test window where it checks the PIC IRQ routing > (it does so with 10 ticks, out of which at least 4 must be delivered). > The theory also says that this is hard to avoid, maybe just less likely > with Gleb's timer drift compensation patches. > > Jan > > PS: Booting with noapic leaves many real boxes useless as well. >