[PATCH v3 1/2] qdev-properties: Add a new macro to validate bitmask for setter

[Like Xu]

The new generic DEFINE_PROP_BITMASK_UINT64 could be used to ensure
that a user-provided property value complies with its bitmask rule
and the default value is recommended to be set in instance_init().

Signed-off-by: Like Xu <like...@linux.intel.com>
---
 hw/core/qdev-properties.c    | 19 +++++++++++++++++++
 include/hw/qdev-properties.h | 12 ++++++++++++
 include/qapi/qmp/qerror.h    |  3 +++
 3 files changed, 34 insertions(+)

diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
index 50f40949f5..3784d3b30d 100644
--- a/hw/core/qdev-properties.c
+++ b/hw/core/qdev-properties.c
@@ -428,6 +428,25 @@ const PropertyInfo qdev_prop_int64 = {
     .set_default_value = qdev_propinfo_set_default_value_int,
 };
 
+static void set_bitmask_uint64(Object *obj, Visitor *v, const char *name,
+                      void *opaque, Error **errp)
+{
+    Property *prop = opaque;
+    uint64_t *ptr = object_field_prop_ptr(obj, prop);
+
+    visit_type_uint64(v, name, ptr, errp);
+
+    if (*ptr & ~prop->bitmask) {
+        error_setg(errp, QERR_INVALID_BITMASK_VALUE, name, prop->bitmask);
+    }
+}
+
+const PropertyInfo qdev_prop_bitmask_uint64 = {
+    .name  = "int64",
+    .get   = get_uint64,
+    .set   = set_bitmask_uint64,
+};
+
 /* --- string --- */
 
 static void release_string(Object *obj, const char *name, void *opaque)
diff --git a/include/hw/qdev-properties.h b/include/hw/qdev-properties.h
index 0ef97d60ce..42f0112e14 100644
--- a/include/hw/qdev-properties.h
+++ b/include/hw/qdev-properties.h
@@ -17,6 +17,7 @@ struct Property {
     const PropertyInfo *info;
     ptrdiff_t    offset;
     uint8_t      bitnr;
+    uint64_t     bitmask;
     bool         set_default;
     union {
         int64_t i;
@@ -53,6 +54,7 @@ extern const PropertyInfo qdev_prop_uint16;
 extern const PropertyInfo qdev_prop_uint32;
 extern const PropertyInfo qdev_prop_int32;
 extern const PropertyInfo qdev_prop_uint64;
+extern const PropertyInfo qdev_prop_bitmask_uint64;
 extern const PropertyInfo qdev_prop_int64;
 extern const PropertyInfo qdev_prop_size;
 extern const PropertyInfo qdev_prop_string;
@@ -102,6 +104,16 @@ extern const PropertyInfo qdev_prop_link;
                 .set_default = true,                         \
                 .defval.u    = (bool)_defval)
 
+/**
+ * The DEFINE_PROP_BITMASK_UINT64 could be used to ensure that
+ * a user-provided value complies with certain bitmask rule and
+ * the default value is recommended to be set in instance_init().
+ */
+#define DEFINE_PROP_BITMASK_UINT64(_name, _state, _field, _bitmask)   \
+    DEFINE_PROP(_name, _state, _field, qdev_prop_bitmask_uint64, uint64_t, \
+                .bitmask    = (_bitmask),                     \
+                .set_default = false)
+
 #define PROP_ARRAY_LEN_PREFIX "len-"
 
 /**
diff --git a/include/qapi/qmp/qerror.h b/include/qapi/qmp/qerror.h
index 596fce0c54..aab7902760 100644
--- a/include/qapi/qmp/qerror.h
+++ b/include/qapi/qmp/qerror.h
@@ -68,4 +68,7 @@
 #define QERR_UNSUPPORTED \
     "this feature or command is not currently supported"
 
+#define QERR_INVALID_BITMASK_VALUE \
+    "the requested value for '%s' violates its bitmask '0x%lx'"
+
 #endif /* QERROR_H */
-- 
2.30.2