When a guest triggers the panic device, QEMU pauses the guest, and libvirt takes the action specified by on_crash. This can interfere with the guest's own crash handling actions (like writing a dump file and rebooting itself) if the guest triggers the panic device first (as Windows does via the Hyper-V crash CPU feature). This is not an obvious side effect of a notification mechanism, so it's worth explaining. Signed-off-by: Ed Swierk <eswierk(a)skyportsystems.com&gt; --- docs/formatdomain.html.in | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index e31a271..1c5fdb9 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -7078,7 +7078,11 @@ qemu-kvm -net nic,model=? /dev/null <h4><a name="elementsPanic">panic device</a></h4> <p> panic device enables libvirt to receive panic notification from a QEMU - guest. + guest. When the guest triggers the panic device, QEMU pauses the guest, and + libvirt takes the action specified by the <code>on_crash</code> element. + Note that this may interfere with the guest's own crash handling actions + (like writing a dump file and rebooting itself) if the guest triggers the + panic device first (as Windows does via the Hyper-V crash CPU feature). <span class="since">Since 1.2.1, QEMU and KVM only</span> </p> <p> -- 1.9.1