hw/qdev-properties-system: Introduce EndianMode QAPI enum

Introduce the EndianMode type and the DEFINE_PROP_ENDIAN() macros.
Endianness can be BIG, LITTLE or unspecified (default).

Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250213122217.62654-2-philmd@linaro.org>

hw/core/qdev-properties-system.c

@@ -1283,3 +1283,14 @@ const PropertyInfo qdev_prop_iothread_vq_mapping_list = {
     .set = set_iothread_vq_mapping_list,
     .release = release_iothread_vq_mapping_list,
 };
+
+/* --- Endian modes */
+
+const PropertyInfo qdev_prop_endian_mode = {
+    .name = "EndianMode",
+    .description = "Endian mode, big/little/unspecified",
+    .enum_table = &EndianMode_lookup,
+    .get = qdev_propinfo_get_enum,
+    .set = qdev_propinfo_set_enum,
+    .set_default_value = qdev_propinfo_set_default_value_enum,
+};

include/hw/qdev-properties-system.h

@@ -30,6 +30,7 @@ extern const PropertyInfo qdev_prop_pcie_link_speed;
 extern const PropertyInfo qdev_prop_pcie_link_width;
 extern const PropertyInfo qdev_prop_cpus390entitlement;
 extern const PropertyInfo qdev_prop_iothread_vq_mapping_list;
+extern const PropertyInfo qdev_prop_endian_mode;
 
 #define DEFINE_PROP_PCI_DEVFN(_n, _s, _f, _d)                   \
     DEFINE_PROP_SIGNED(_n, _s, _f, _d, qdev_prop_pci_devfn, int32_t)
@@ -97,4 +98,10 @@ extern const PropertyInfo qdev_prop_iothread_vq_mapping_list;
     DEFINE_PROP(_name, _state, _field, qdev_prop_iothread_vq_mapping_list, \
                 IOThreadVirtQueueMappingList *)
 
+#define DEFINE_PROP_ENDIAN(_name, _state, _field, _default) \
+    DEFINE_PROP_UNSIGNED(_name, _state, _field, _default, \
+                         qdev_prop_endian_mode, EndianMode)
+#define DEFINE_PROP_ENDIAN_NODEFAULT(_name, _state, _field) \
+    DEFINE_PROP_ENDIAN(_name, _state, _field, ENDIAN_MODE_UNSPECIFIED)
+
 #endif

qapi/common.json

@@ -212,3 +212,17 @@
 ##
 { 'struct': 'HumanReadableText',
   'data': { 'human-readable-text': 'str' } }
+
+##
+# @EndianMode:
+#
+# @unspecified: Endianness not specified
+#
+# @little: Little endianness
+#
+# @big: Big endianness
+#
+# Since: 10.0
+##
+{ 'enum': 'EndianMode',
+  'data': [ 'unspecified', 'little', 'big' ] }