Re: [Qemu-devel] [PATCH v15 4/6] pvpanic: add document of pvpanic

[Paolo Bonzini <pbonzini@redhat.com>]

Il 21/03/2013 09:35, Hu Tao ha scritto:
> Signed-off-by: Hu Tao <hutao@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.

Please document the ISA interface too.

> +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.

Please document RDPT too, and mention that the ACPI device will
automatically refer to the right port in case it is modified.

> +To use it, one will have to:
> +
> +1. add the device by specifying `-device pvpanic' in the qemu command
> +   line.

As mentioned earlier, I'd like this to be the default in 1.5 and newer
machine types.

Paolo

> +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.
>