qom: introduce get/set methods for Property

This patch adds a visitor interface to Property.  This way, QOM will be
able to expose Properties that access a fixed field in a struct without
exposing also the everything-is-a-string "feature" of qdev properties.

Whenever the printed representation in both QOM and qdev (which is
typically the case for device backends), parse/print code can be reused
via get_generic/set_generic.  Dually, whenever multiple PropertyInfos
have the same representation in both the struct and the visitors the
code can be reused (for example among all of int32/uint32/hex32).

Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/hw/qdev.h b/hw/qdev.h
index 94f5ce91b4..42495aed04 100644
--- a/hw/qdev.h
+++ b/hw/qdev.h
@@ -158,9 +158,13 @@ struct PropertyInfo {
     const char *name;
     size_t size;
     enum PropertyType type;
+    int64_t min;
+    int64_t max;
     int (*parse)(DeviceState *dev, Property *prop, const char *str);
     int (*print)(DeviceState *dev, Property *prop, char *dest, size_t len);
     void (*free)(DeviceState *dev, Property *prop);
+    DevicePropertyAccessor *get;
+    DevicePropertyAccessor *set;
 };
 
 typedef struct GlobalProperty {