qdev: rework device properties.

This patch is a major overhaul of the device properties.  The properties
are saved directly in the device state struct now, the linked list of
property values is gone.

Advantages:
  * We don't have to maintain the list with the property values.
  * The value in the property list and the value actually used by
    the device can't go out of sync any more (used to happen for
    the pci.devfn == -1 case) because there is only one place where
    the value is stored.
  * A record describing the property is required now, you can't set
    random properties any more.

There are bus-specific and device-specific properties.  The former
should be used for properties common to all bus drivers.  Typical
use case is bus addressing, i.e. pci.devfn and i2c.address.

Properties have a PropertyInfo struct attached with name, size and
function pointers to parse and print properties.  A few common property
types have PropertyInfos defined in qdev-properties.c.  Drivers are free
to implement their own very special property parsers if needed.

Properties can have default values.  If unset they are zero-filled.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/hw/i2c.c b/hw/i2c.c
index 98aa7fcd24..42a5d7a6b8 100644
--- a/hw/i2c.c
+++ b/hw/i2c.c
@@ -20,6 +20,14 @@ struct i2c_bus
 static struct BusInfo i2c_bus_info = {
     .name = "I2C",
     .size = sizeof(i2c_bus),
+    .props = (Property[]) {
+        {
+            .name   = "address",
+            .info   = &qdev_prop_uint32,
+            .offset = offsetof(struct i2c_slave, address),
+        },
+        {/* end of list */}
+    }
 };
 
 static void i2c_bus_save(QEMUFile *f, void *opaque)
@@ -151,7 +159,6 @@ static void i2c_slave_qdev_init(DeviceState *dev, DeviceInfo *base)
     i2c_slave *s = I2C_SLAVE_FROM_QDEV(dev);
 
     s->info = info;
-    s->address = qdev_get_prop_int(dev, "address", 0);
 
     info->init(s);
 }
@@ -169,7 +176,7 @@ DeviceState *i2c_create_slave(i2c_bus *bus, const char *name, int addr)
     DeviceState *dev;
 
     dev = qdev_create(&bus->qbus, name);
-    qdev_set_prop_int(dev, "address", addr);
+    qdev_prop_set_uint32(dev, "address", addr);
     qdev_init(dev);
     return dev;
 }