On 02/29/2012 12:17 PM, Wen Congyang wrote: > >>> > >> Yes, crash can be so severe that it is not even detected by a kernel > >> itself, so not OOPS message even printed. But in most cases if kernel is > >> functional enough to print OOPS it is functional enough to call single > >> hypercall instruction. > > > > Why not print the oops to virtio-serial? Or even just a regular serial > > port? That's what bare metal does. > > If virtio-serial's driver has bug or the guest doesn't have such device... We have the same issue with the hypercall; and virtio-serial is available on many deployed versions. > > > >>>> Having special kdump > >>>> kernel that transfers dump to a host via virtio-serial channel though > >>>> sounds interesting. May be that's what you mean. > >>> > >>> Yes. The "panic, starting dump" signal should be initiated by the > >>> panicking kernel though, in case the dump fails. > >>> > >> Then panic hypercall sounds like a reasonable solution. > > > > It is, but I'm trying to see if we can get away with doing nothing. > > > > If we have a reliable way with doing nothing, it is better. But I donot > find such way. We won't have a 100% reliable way. But I think a variant of the driver that doesn't use interrupts, or just using the ordinary serial driver, should be reliable enough. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html