@@ -1,14 +1,18 @@
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
+pvpanic device is a simulated ISA/SysBus 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,
+The ma:wqnagement 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.
+When pvpanic device is implemented as a ISA device, it supports IOPORT
+mode. Since QEMU v3.2 pvpanic also supports MMIO mode, it will be
+implemented as a SYSBUS device.
+
ISA Interface
-------------
@@ -19,6 +23,14 @@ 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.
+SYSBUS Interface
+----------------
+
+The SYSBUS interface is similar to the ISA interface except that it uses
+MMIO. For example, the arm virt machine could put the pvpanic device at
+[0x9070000, 0x9070001] and currently only the first byte is used.
+
+
ACPI Interface
--------------
Add mmio support info in docs/specs/pvpanic.txt. Signed-off-by: Peng Hao <peng.hao2@zte.com.cn> --- docs/specs/pvpanic.txt | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-)