From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: [PATCH] kvm: notify host when guest paniced Date: Wed, 29 Feb 2012 11:55:57 +0200 Message-ID: <20120229095557.GE24600@redhat.com> References: <4F4AF1FB.6000903@cn.fujitsu.com> <4F4CB926.6050600@redhat.com> <4F4D7F5E.5040202@cn.fujitsu.com> <4F4DF4C6.90609@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Wen Congyang , kvm list , KAMEZAWA Hiroyuki , "Daniel P. Berrange" , linux-kernel@vger.kernel.org, qemu-devel To: Avi Kivity Return-path: Content-Disposition: inline In-Reply-To: <4F4DF4C6.90609@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Wed, Feb 29, 2012 at 11:49:58AM +0200, Avi Kivity wrote: > On 02/29/2012 03:29 AM, Wen Congyang wrote: > > At 02/28/2012 07:23 PM, Avi Kivity Wrote: > > > On 02/27/2012 05:01 AM, Wen Congyang wrote: > > >> We can know the guest is paniced when the guest runs on xen. > > >> But we do not have such feature on kvm. This patch implemnts > > >> this feature, and the implementation is the same as xen: > > >> register panic notifier, and call hypercall when the guest > > >> is paniced. > > > > > > What's the motivation for this? "Xen does this" is insufficient. > > > > Another purpose is: management app(for example: libvirt) can do auto > > dump when the guest is crashed. If management app does not do auto > > dump, the guest's user can do dump by hand if he sees the guest is > > paniced. > > > > I am thinking about another status: dumping. This status tells > > the guest's user that the guest is paniced, and the OS's dump function > > is working. > > > > These two status can tell the guest's user whether the guest is pancied, > > and what should he do if the guest is paniced. > > > > How about using a virtio-serial channel for this? You can transfer any > amount of information (including the dump itself). > Isn't it unreliable after the guest panicked? Having special kdump kernel that transfers dump to a host via virtio-serial channel though sounds interesting. May be that's what you mean. -- Gleb.