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>
---
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