Re: [Qemu-devel] [RFC PATCH v2 0/3] Start fixing the pvpanic mess

[Paolo Bonzini]

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.

Paolo