From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759460Ab2CNI2F (ORCPT ); Wed, 14 Mar 2012 04:28:05 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:48086 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754131Ab2CNI2B (ORCPT ); Wed, 14 Mar 2012 04:28:01 -0400 X-IronPort-AV: E=Sophos;i="4.73,583,1325433600"; d="scan'208";a="4532394" Message-ID: <4F6056FE.3020202@cn.fujitsu.com> Date: Wed, 14 Mar 2012 16:29:50 +0800 From: Wen Congyang User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100413 Fedora/3.0.4-2.fc13 Thunderbird/3.0.4 MIME-Version: 1.0 To: Avi Kivity CC: "Daniel P. Berrange" , kvm list , qemu-devel , "linux-kernel@vger.kernel.org" , KAMEZAWA Hiroyuki , Jan Kiszka , Gleb Natapov Subject: Re: [PATCH 0/2 v3] kvm: notify host when guest panicked References: <4F58664D.1070800@cn.fujitsu.com> <4F58943E.1050402@redhat.com> <4F595B31.9090301@cn.fujitsu.com> <4F5DBC26.7060204@cn.fujitsu.com> <4F5DD0FD.9070904@redhat.com> <20120313091843.GB3800@redhat.com> <4F5F25BF.7060100@redhat.com> In-Reply-To: <4F5F25BF.7060100@redhat.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2012-03-14 16:25:54, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2012-03-14 16:25:56, Serialize complete at 2012-03-14 16:25:56 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org At 03/13/2012 06:47 PM, Avi Kivity Wrote: > On 03/13/2012 11:18 AM, Daniel P. Berrange wrote: >> On Mon, Mar 12, 2012 at 12:33:33PM +0200, Avi Kivity wrote: >>> On 03/12/2012 11:04 AM, Wen Congyang wrote: >>>> Do you have any other comments about this patch? >>>> >>> >>> Not really, but I'm not 100% convinced the patch is worthwhile. It's >>> likely to only be used by Linux, which has kexec facilities, and you can >>> put talk to management via virtio-serial and describe the crash in more >>> details than a simple hypercall. >> >> As mentioned before, I don't think virtio-serial is a good fit for this. >> We want something that is simple & guaranteed always available. Using >> virtio-serial requires significant setup work on both the host and guest. > > So what? It needs to be done anyway for the guest agent. > >> Many management application won't know to make a vioserial device available >> to all guests they create. > > Then they won't know to deal with the panic event either. > >> Most administrators won't even configure kexec, >> let alone virtio serial on top of it. > > It should be done by the OS vendor, not the individual admin. > >> The hypercall requires zero host >> side config, and zero guest side config, which IMHO is what we need for >> this feature. > > If it was this one feature, yes. But we keep getting more and more > features like that and we bloat the hypervisor. There's a reason we > have a host-to-guest channel, we should use it. > I donot know how to use virtio-serial. I start vm like this: qemu ...\ -device virtio-serial \ -chardev socket,path=/tmp/foo,server,nowait,id=foo \ -device virtserialport,chardev=foo,name=port1 ... You said that there are too many channels. Does it mean /tmp/foo is a channel? Thanks Wen Congyang