From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wen Congyang Subject: Re: [PATCH 0/2 v3] kvm: notify host when guest panicked Date: Wed, 14 Mar 2012 16:29:50 +0800 Message-ID: <4F6056FE.3020202@cn.fujitsu.com> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Gleb Natapov , kvm list , Jan Kiszka , qemu-devel , "linux-kernel@vger.kernel.org" , KAMEZAWA Hiroyuki To: Avi Kivity Return-path: In-Reply-To: <4F5F25BF.7060100@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org List-Id: kvm.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