lkml.org 
[lkml]   [2012]   [Feb]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] kvm: notify host when guest paniced
On 02/29/2012 12:31 PM, Wen Congyang wrote:
> At 02/29/2012 06:05 PM, Avi Kivity Wrote:
> > On 02/29/2012 11:58 AM, Daniel P. Berrange wrote:
> >>>
> >>> How about using a virtio-serial channel for this? You can transfer any
> >>> amount of information (including the dump itself).
> >>
> >> When the guest OS has crashed, any dumps will be done from the host
> >> OS using libvirt's core dump mechanism. The guest OS isn't involved
> >> and is likely too dead to be of any use anyway. Likewise it is
> >> quite probably too dead to work a virtio-serial channel or any
> >> similarly complex device. We're really just after the simplest
> >> possible notification that the guest kernel has paniced.
> >
> > If it's alive enough to panic, it's alive enough to kexec its kdump
> > kernel. After that it can do anything.
> >
> > Guest-internal dumps are more useful IMO that host-initiated dumps. In
>
> Yes, guest-internal dump is better than host dump. But the user may not
> start guest-internal dump or guest-internal dump failed. So we need the
> following feature:
> 1. If the guest-internal dump does not work, the guest's status is 'crashed'.
> And then the user does the host dump.
> 2. If the guest-internal dump is working, the guest's status should be
> 'dumping'. The user see this status and know the guest has paniced, and
> the guest-internal dump is working.

I agree. There is room for host dump, and we do want notification about
what the guest is doing. The question is whether we should reuse
virtio-serial for guest-host communication in this case. It's more
complicated, but allows us to avoid touching the hypervisor.

--
error compiling committee.c: too many arguments to function



\
 
 \ /
  Last update: 2012-02-29 11:49    [W:0.060 / U:0.924 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site