From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] Print Guest VMCS state on vmexit failure Date: Tue, 20 Oct 2009 18:08:57 +0900 Message-ID: <4ADD7E29.1070100@redhat.com> References: <1256025045-4972-1-git-send-email-clalance@redhat.com> <4ADD70CB.10109@redhat.com> <4ADD77F0.6010102@redhat.com> <20091020085522.GA6416@develbox.linuxbox.cz> <4ADD7B83.2050603@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Nikola Ciprich , kvm@vger.kernel.org, nikola.ciprich@linuxbox.cz To: Chris Lalancette Return-path: Received: from mx1.redhat.com ([209.132.183.28]:63470 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751494AbZJTJJF (ORCPT ); Tue, 20 Oct 2009 05:09:05 -0400 In-Reply-To: <4ADD7B83.2050603@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 10/20/2009 05:57 PM, Chris Lalancette wrote: > Nikola Ciprich wrote: > >> Hi, >> maybe it's stupid question, but is this available also when qemu/kvm >> is started using libvirt& stuff? I think it uses monitor so it's >> inaccessible for user no? >> > Yes and no. The monitor is inaccessible when using libvirt, but I totally > forgot that qemu dumps the register state to stderr before abort()'ing on an > unknown vm exit. Libvirt takes the output from stderr and stores it in > /var/log/libvirt/qemu/. So you would still be able to see this > output when using libvirt. > We've dropped the stderr part (IIRC), but nothing prevents libvirt from accessing the register state and providing it to the user. There's also the multiple monitor support which can be used for debugging. Finally, you can connect with gdb (need to dynamically start the gdb server via the monitor, again needs libvirt support). -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.