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, 41 insertions, 0 deletions

diff --git a/hw/qdev-addr.c b/hw/qdev-addr.c
index 305c2d37b0..5ddda2d0f4 100644
--- a/hw/qdev-addr.c
+++ b/hw/qdev-addr.c
@@ -18,12 +18,53 @@ static int print_taddr(DeviceState *dev, Property *prop, char *dest, size_t len)
     return snprintf(dest, len, "0x" TARGET_FMT_plx, *ptr);
 }
 
+static void get_taddr(DeviceState *dev, Visitor *v, void *opaque,
+                      const char *name, Error **errp)
+{
+    Property *prop = opaque;
+    target_phys_addr_t *ptr = qdev_get_prop_ptr(dev, prop);
+    int64_t value;
+
+    value = *ptr;
+    visit_type_int(v, &value, name, errp);
+}
+
+static void set_taddr(DeviceState *dev, Visitor *v, void *opaque,
+                      const char *name, Error **errp)
+{
+    Property *prop = opaque;
+    target_phys_addr_t *ptr = qdev_get_prop_ptr(dev, prop);
+    Error *local_err = NULL;
+    int64_t value;
+
+    if (dev->state != DEV_STATE_CREATED) {
+        error_set(errp, QERR_PERMISSION_DENIED);
+        return;
+    }
+
+    visit_type_int(v, &value, name, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+    if ((uint64_t)value <= (uint64_t) ~(target_phys_addr_t)0) {
+        *ptr = value;
+    } else {
+        error_set(errp, QERR_PROPERTY_VALUE_OUT_OF_RANGE,
+                  dev->id?:"", name, value, (uint64_t) 0,
+                  (uint64_t) ~(target_phys_addr_t)0);
+    }
+}
+
+
 PropertyInfo qdev_prop_taddr = {
     .name  = "taddr",
     .type  = PROP_TYPE_TADDR,
     .size  = sizeof(target_phys_addr_t),
     .parse = parse_taddr,
     .print = print_taddr,
+    .get   = get_taddr,
+    .set   = set_taddr,
 };
 
 void qdev_prop_set_taddr(DeviceState *dev, const char *name, target_phys_addr_t value)