Signed-off-by: Hu Tao <hu...@cn.fujitsu.com> --- docs/specs/pvpanic.txt | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 docs/specs/pvpanic.txt
diff --git a/docs/specs/pvpanic.txt b/docs/specs/pvpanic.txt new file mode 100644 index 0000000..761d20c --- /dev/null +++ b/docs/specs/pvpanic.txt @@ -0,0 +1,25 @@ +PVPANIC DEVICE +============== + +pvpanic device is a simulated ISA device, through which guest panic +event is sent to qemu, and a QMP event is generated. This allows +management apps(e.g. libvirt) to be notified and respond to the +event. + +pvpanic uses port 0x505 by default to receive panic event from guest. +The port is configurable by specifying ioport property. + +pvpanic device is defined with ACPI ID "QEMU0001". To send panic +event, guest evaluates method WRPT, specifying a byte, bit 0 set, +as argument. Other bits are reserved. + +To use it, one will have to: + +1. add the device by specifying `-device pvpanic' in the qemu command + line. + +2. load pvpanic device driver in guest OS. + +The management app has the options of waiting for GUEST_PANICKED events, +and/or polling for guest-panicked RunState, to learn when the pvpanic +device has fired a panic event. -- 1.8.1.4
