From: Peng Hao <peng.h...@zte.com.cn>
Add mmio support info in docs/specs/pvpanic.txt.
Reviewed-by: Andrew Jones <drjo...@redhat.com>
Signed-off-by: Peng Hao <peng.h...@zte.com.cn>
Signed-off-by: Mihai Carabas <mihai.cara...@oracle.com>
---
docs/specs/pvpanic.txt | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/docs/specs/pvpanic.txt b/docs/specs/pvpanic.txt
index a90fbca..b50140b 100644
--- a/docs/specs/pvpanic.txt
+++ b/docs/specs/pvpanic.txt
@@ -1,7 +1,7 @@
PVPANIC DEVICE
==============
-pvpanic device is a simulated ISA device, through which a guest panic
+pvpanic device is a simulated 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.
@@ -9,6 +9,9 @@ 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.
+The pvpanic device can be implemented as an ISA device (using IOPORT),
+or, since qemu 4.0, as a SYSBUS device (using MMIO).
+
ISA Interface
-------------
@@ -24,6 +27,13 @@ bit 1: a guest panic has happened and will be handled by the
guest;
the host should record it or report it, but should not affect
the execution of the guest.
+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
+[0x90b0000, 0x90b0001], where currently only the first byte is used.
+
ACPI Interface
--------------
--
1.8.3.1
