Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756242Ab2HNO4N (ORCPT ); Tue, 14 Aug 2012 10:56:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:22118 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751517Ab2HNO4M convert rfc822-to-8bit (ORCPT ); Tue, 14 Aug 2012 10:56:12 -0400 Subject: Re: [PATCH v8] kvm: notify host when the guest is panicked Mime-Version: 1.0 (Apple Message framework v1278) Content-Type: text/plain; charset=us-ascii From: Yan Vugenfirer In-Reply-To: <502A2B7A.3070801@siemens.com> Date: Tue, 14 Aug 2012 17:55:54 +0300 Cc: "Daniel P. Berrange" , Marcelo Tosatti , Wen Congyang , kvm list , qemu-devel , "linux-kernel@vger.kernel.org" , Avi Kivity , KAMEZAWA Hiroyuki , Gleb Natapov Content-Transfer-Encoding: 8BIT Message-Id: <86E2467F-0EA3-4A03-BD89-58E41F7DB808@redhat.com> References: <5021D235.4050800@cn.fujitsu.com> <20120813182132.GB25268@amt.cnet> <20120814085619.GA32708@redhat.com> <502A2B7A.3070801@siemens.com> To: Jan Kiszka Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2222 Lines: 58 On Aug 14, 2012, at 1:42 PM, Jan Kiszka wrote: > On 2012-08-14 10:56, Daniel P. Berrange wrote: >> On Mon, Aug 13, 2012 at 03:21:32PM -0300, Marcelo Tosatti wrote: >>> On Wed, Aug 08, 2012 at 10:43:01AM +0800, Wen Congyang wrote: >>>> We can know the guest is panicked when the guest runs on xen. >>>> But we do not have such feature on kvm. >>>> >>>> Another purpose of this feature is: management app(for example: >>>> libvirt) can do auto dump when the guest is panicked. If management >>>> app does not do auto dump, the guest's user can do dump by hand if >>>> he sees the guest is panicked. >>>> >>>> We have three solutions to implement this feature: >>>> 1. use vmcall >>>> 2. use I/O port >>>> 3. use virtio-serial. >>>> >>>> We have decided to avoid touching hypervisor. The reason why I choose >>>> choose the I/O port is: >>>> 1. it is easier to implememt >>>> 2. it does not depend any virtual device >>>> 3. it can work when starting the kernel >>> >>> How about searching for the "Kernel panic - not syncing" string >>> in the guests serial output? Say libvirtd could take an action upon >>> that? >> >> No, this is not satisfactory. It depends on the guest OS being >> configured to use the serial port for console output which we >> cannot mandate, since it may well be required for other purposes. > Please don't forget Windows guests, there is no console and no "Kernel Panic" string ;) What I used for debugging purposes on Windows guest is to register a bugcheck callback in virtio-net driver and write 1 to VIRTIO_PCI_ISR register. Yan. > Well, we have more than a single serial port, even when leaving > virtio-serial aside... > > Jan > > -- > Siemens AG, Corporate Technology, CT RTC ITP SDP-DE > Corporate Competence Center Embedded Linux > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/