[Qemu-devel] [PATCH v2 2/5] acpi: introduce TYPE_ACPI_DEVICE_IF interface

[Igor Mammedov <imammedo@redhat.com>]

... it will be used to abstract generic ACPI bits from
device that implements ACPI interface.

ACPIOSTInfo type is used for passing-through raw _OST
event/status codes reported by guest OS to a management
layer. It lets management tools interpret values
as specified by ACPI spec if it is interested in it.

QEMU doesn't encode these values as enum, since it
doesn't need to handle them and it allows interface
to scale well without any changes in QEMU while guest
OS and management evolves in time.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
v3:
 - fix ACPIOSTInfo docs comments
 - fix sgramar errors in commit message
v2:
 - fix doc comments, describe not described fields
 - add slot-type field with DIMM type for now, which later
   we could extend to PCI slots and probably to CPUs
 - extend commit message describing why source/status
   are raw integers vs enum.
---
 hw/acpi/Makefile.objs                |    1 +
 hw/acpi/acpi_interface.c             |   15 ++++++++++++
 include/hw/acpi/acpi_dev_interface.h |   43 ++++++++++++++++++++++++++++++++++
 qapi-schema.json                     |   31 ++++++++++++++++++++++++
 4 files changed, 90 insertions(+), 0 deletions(-)
 create mode 100644 hw/acpi/acpi_interface.c
 create mode 100644 include/hw/acpi/acpi_dev_interface.h

diff --git a/hw/acpi/Makefile.objs b/hw/acpi/Makefile.objs
index 004e1b2..acd2389 100644
--- a/hw/acpi/Makefile.objs
+++ b/hw/acpi/Makefile.objs
@@ -1,2 +1,3 @@
 common-obj-$(CONFIG_ACPI) += core.o piix4.o ich9.o pcihp.o cpu_hotplug.o
 common-obj-$(CONFIG_ACPI) += memory_hotplug.o
+common-obj-$(CONFIG_ACPI) += acpi_interface.o
diff --git a/hw/acpi/acpi_interface.c b/hw/acpi/acpi_interface.c
new file mode 100644
index 0000000..c181bb2
--- /dev/null
+++ b/hw/acpi/acpi_interface.c
@@ -0,0 +1,15 @@
+#include "hw/acpi/acpi_dev_interface.h"
+#include "qemu/module.h"
+
+static void register_types(void)
+{
+    static const TypeInfo acpi_dev_if_info = {
+        .name          = TYPE_ACPI_DEVICE_IF,
+        .parent        = TYPE_INTERFACE,
+        .class_size = sizeof(AcpiDeviceIfClass),
+    };
+
+    type_register_static(&acpi_dev_if_info);
+}
+
+type_init(register_types)
diff --git a/include/hw/acpi/acpi_dev_interface.h b/include/hw/acpi/acpi_dev_interface.h
new file mode 100644
index 0000000..f245f8d
--- /dev/null
+++ b/include/hw/acpi/acpi_dev_interface.h
@@ -0,0 +1,43 @@
+#ifndef ACPI_DEV_INTERFACE_H
+#define ACPI_DEV_INTERFACE_H
+
+#include "qom/object.h"
+#include "qapi-types.h"
+
+#define TYPE_ACPI_DEVICE_IF "acpi-device-interface"
+
+#define ACPI_DEVICE_IF_CLASS(klass) \
+     OBJECT_CLASS_CHECK(AcpiDeviceIfClass, (klass), \
+                        TYPE_ACPI_DEVICE_IF)
+#define ACPI_DEVICE_IF_GET_CLASS(obj) \
+     OBJECT_GET_CLASS(AcpiDeviceIfClass, (obj), \
+                      TYPE_ACPI_DEVICE_IF)
+#define ACPI_DEVICE_IF(obj) \
+     INTERFACE_CHECK(AcpiDeviceIf, (obj), \
+                     TYPE_ACPI_DEVICE_IF)
+
+
+typedef struct AcpiDeviceIf {
+    /* <private> */
+    Object Parent;
+} AcpiDeviceIf;
+
+/**
+ * AcpiDeviceIfClass:
+ *
+ * ospm_status: returns status of ACPI device objects, reported
+ *              via _OST method if device supports it.
+ *
+ * Interface is designed for providing unified interface
+ * to generic ACPI functionality that could be used without
+ * knowledge about internals of actual device that implements
+ * ACPI interface.
+ */
+typedef struct AcpiDeviceIfClass {
+    /* <private> */
+    InterfaceClass parent_class;
+
+    /* <public> */
+    void (*ospm_status)(AcpiDeviceIf *adev, ACPIOSTInfoList ***list);
+} AcpiDeviceIfClass;
+#endif
diff --git a/qapi-schema.json b/qapi-schema.json
index 60e5551..8179c79 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -4887,3 +4887,34 @@
 # Since: 2.1
 ##
 { 'command': 'query-memory-devices', 'returns': ['MemoryDeviceInfo'] }
+
+## @ACPISlotType
+#
+# @DIMM: memory slot
+#
+{ 'enum': 'ACPISlotType', 'data': [ 'DIMM' ] }
+
+## @ACPIOSTInfo
+#
+# OSPM Status Indication for a device
+# For description of possible values of @source and @status fields
+# see "_OST (OSPM Status Indication)" chapter of ACPI5.0 spec.
+#
+# @device: #optional device ID associated with slot
+#
+# @slot: slot ID, unique per slot of a given @slot-type
+#
+# @slot-type: type of the slot
+#
+# @source: an integer containing the source event
+#
+# @status: an integer containing the status code
+#
+# Since: 2.1
+##
+{ 'type': 'ACPIOSTInfo',
+  'data'  : { '*device': 'str',
+              'slot': 'str',
+              'slot-type': 'ACPISlotType',
+              'source': 'int',
+              'status': 'int' } }
-- 
1.7.1