On Wed, Aug 21, 2013 at 06:56:52PM +0200, Paolo Bonzini wrote: > Il 21/08/2013 18:55, Daniel P. Berrange ha scritto: > > On Wed, Aug 21, 2013 at 06:51:11PM +0200, Paolo Bonzini wrote: > >> Il 21/08/2013 18:48, Daniel P. Berrange ha scritto: > >>> No, <on_crash> is the right thing to be using for this from > >>> libvirt's pov & I don't think we should invent something new. > >>> The <on_crash> element has always been intended to represent > >>> handling of guest panics, not qemu internal errors. > >> > >> Actually for Xen HVM guests, it mostly traps things such as failed > >> vmentries. The Xen PV-on-HVM drivers do not register a panic notifier > >> that moves the guest to the "crashed" state. > >> > >> <on_crash> cannot be salvaged, in my opinion, because all domain XMLs in > >> the wild will have a setting that causes libvirt to add "-device > >> isa-pvpanic". Thus changing libvirt versions will change guest > >> hardware, which is _very_ bad. > >> > >> In addition, Windows XP and 2003 will show the annoying device wizard > >> upon a libvirt upgrade, and fixing this is what surfaced all the mess. > > > > The existance of a <on_crash> element should not be having any > > effect on what hardware we create. That is merely a lifecycle > > policy setting that should be completely independant of the > > guest device model. > > > > eg it is valid to have <on_crash> present in the XML at all > > times, even if there's no pvpanic device present. That simply > > means the actions will never be triggered. > > So are you suggesting to add a <pvpanic/> element to <devices>? That > may be fine, but it doesn't seem very user-friendly. Yes, if we're going to have pvpanic be user controllable, it must be via an explicit device element. None of the <on_XXXX> elements should have any impact on guest ABI model. They're purely lifecycle policy settings. Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list