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| -rw-r--r-- | docs/specs/pvpanic.txt | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/docs/specs/pvpanic.txt b/docs/specs/pvpanic.txt new file mode 100644 index 0000000000..c7bbacc778 --- /dev/null +++ b/docs/specs/pvpanic.txt @@ -0,0 +1,39 @@ +PVPANIC DEVICE +============== + +pvpanic device is a simulated ISA device, through which a 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. + +The management app has the option of waiting for GUEST_PANICKED events, +and/or polling for guest-panicked RunState, to learn when the pvpanic +device has fired a panic event. + +ISA Interface +------------- + +pvpanic exposes a single I/O port, by default 0x505. On read, the bits +recognized by the device are set. Software should ignore bits it doesn't +recognize. On write, the bits not recognized by the device are ignored. +Software should set only bits both itself and the device recognize. +Currently, only bit 0 is recognized, setting it indicates a guest panic +has happened. + +ACPI Interface +-------------- + +pvpanic device is defined with ACPI ID "QEMU0001". Custom methods: + +RDPT: To determine whether guest panic notification is supported. +Arguments: None +Return: Returns a byte, bit 0 set to indicate guest panic + notification is supported. Other bits are reserved and + should be ignored. + +WRPT: To send a guest panic event +Arguments: Arg0 is a byte, with bit 0 set to indicate guest panic has + happened. Other bits are reserved and should be cleared. +Return: None + +The ACPI device will automatically refer to the right port in case it +is modified. |