diff mbox

[17/23] qom: move properties from qdev to object

Message ID 1327957741-5842-17-git-send-email-aliguori@us.ibm.com
State New
Headers show

Commit Message

Anthony Liguori Jan. 30, 2012, 9:08 p.m. UTC
This is mostly code movement although not entirely.  This makes properties part
of the Object base class which means that we can now start using Object in a
meaningful way outside of qdev.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
 hw/mc146818rtc.c      |    8 +-
 hw/pc_piix.c          |    6 +-
 hw/piix_pci.c         |    4 +-
 hw/qdev-addr.c        |    6 +-
 hw/qdev-monitor.c     |   21 ++-
 hw/qdev-properties.c  |   53 ++++--
 hw/qdev.c             |  490 ++-----------------------------------------------
 hw/qdev.h             |  277 +---------------------------
 include/qemu/object.h |  223 ++++++++++++++++++++++-
 qapi-schema.json      |   22 +-
 qmp.c                 |   34 ++--
 qom/object.c          |  457 +++++++++++++++++++++++++++++++++++++++++++++
 12 files changed, 785 insertions(+), 816 deletions(-)

Comments

Paolo Bonzini Jan. 31, 2012, 7:46 a.m. UTC | #1
On 01/30/2012 10:08 PM, Anthony Liguori wrote:
> This is mostly code movement although not entirely.  This makes properties part
> of the Object base class which means that we can now start using Object in a
> meaningful way outside of qdev.

Can we move them to an intermediate base class?  I would like to use QOM 
refcounting for other objects, such as SCSIRequest, so it is important 
to have Object as a pretty light-weight class.  Also (and perhaps more 
importantly), interface implementations are Objects too and they do not 
need properties.

I cannot think of any better name than IntrospectableObject, which is 
quite a mouthful.  I suppose that we could have the base class but still 
pass the objects to the function as Object * and use the OBJECT macro. 
Nothing of this is in a hot path anyway.

Paolo
Anthony Liguori Feb. 1, 2012, 8:01 p.m. UTC | #2
On 01/31/2012 01:46 AM, Paolo Bonzini wrote:
> On 01/30/2012 10:08 PM, Anthony Liguori wrote:
>> This is mostly code movement although not entirely. This makes properties part
>> of the Object base class which means that we can now start using Object in a
>> meaningful way outside of qdev.
>
> Can we move them to an intermediate base class? I would like to use QOM
> refcounting for other objects, such as SCSIRequest, so it is important to have
> Object as a pretty light-weight class. Also (and perhaps more importantly),
> interface implementations are Objects too and they do not need properties.
>
> I cannot think of any better name than IntrospectableObject, which is quite a
> mouthful. I suppose that we could have the base class but still pass the objects
> to the function as Object * and use the OBJECT macro. Nothing of this is in a
> hot path anyway.

I'm just not sure how I feel about this.

The overhead of properties are small in terms of object size.  It's just 
sizeof(void *).

I think that read-only properties could be interesting for SCSIRequest.  For 
instance, I can imagine having SCSIRequest is-a BlockRequest and having an error 
property associated with it.  That would provide a nice way to have an info io 
operation that returned a list of failed I/O requests or something like that.

Regards,

Anthony Liguori

>
> Paolo
>
Paolo Bonzini Feb. 1, 2012, 8:33 p.m. UTC | #3
On 02/01/2012 09:01 PM, Anthony Liguori wrote:
> I think that read-only properties could be interesting for SCSIRequest.
> For instance, I can imagine having SCSIRequest is-a BlockRequest and
> having an error property associated with it.  That would provide a nice
> way to have an info io operation that returned a list of failed I/O
> requests or something like that.

SCSIRequests can have a BlockRequest as a child; not all SCSIRequests 
have I/O attached to them, but I see the general concept.  I'm not sure 
we'll be able to optimize enough, but we can certainly try...

Paolo
diff mbox

Patch

diff --git a/hw/mc146818rtc.c b/hw/mc146818rtc.c
index c1f4ef4..346a95e 100644
--- a/hw/mc146818rtc.c
+++ b/hw/mc146818rtc.c
@@ -626,10 +626,10 @@  static void visit_type_int32(Visitor *v, int *value, const char *name, Error **e
     visit_type_int(v, &val, name, errp);
 }
 
-static void rtc_get_date(DeviceState *dev, Visitor *v, void *opaque,
+static void rtc_get_date(Object *obj, Visitor *v, void *opaque,
                          const char *name, Error **errp)
 {
-    ISADevice *isa = ISA_DEVICE(dev);
+    ISADevice *isa = ISA_DEVICE(obj);
     RTCState *s = DO_UPCAST(RTCState, dev, isa);
 
     visit_start_struct(v, NULL, "struct tm", name, 0, errp);
@@ -676,8 +676,8 @@  static int rtc_initfn(ISADevice *dev)
     qdev_set_legacy_instance_id(&dev->qdev, base, 2);
     qemu_register_reset(rtc_reset, s);
 
-    qdev_property_add(&s->dev.qdev, "date", "struct tm",
-                      rtc_get_date, NULL, NULL, s, NULL);
+    object_property_add(OBJECT(s), "date", "struct tm",
+                        rtc_get_date, NULL, NULL, s, NULL);
 
     return 0;
 }
diff --git a/hw/pc_piix.c b/hw/pc_piix.c
index a285ad2..c06f1b5 100644
--- a/hw/pc_piix.c
+++ b/hw/pc_piix.c
@@ -229,7 +229,7 @@  static void pc_init1(MemoryRegion *system_memory,
 
     dev = pc_vga_init(isa_bus, pci_enabled ? pci_bus : NULL);
     if (dev) {
-        qdev_property_add_child(qdev_get_root(), "vga", dev, NULL);
+        object_property_add_child(object_get_root(), "vga", OBJECT(dev), NULL);
     }
 
     if (xen_enabled()) {
@@ -267,8 +267,8 @@  static void pc_init1(MemoryRegion *system_memory,
          * For now, let's "fix" this by making judicious use of paths.  This
          * is not generally the right way to do this.
          */
-        qdev_property_add_child(qdev_resolve_path("/i440fx/piix3", NULL),
-                                "rtc", (DeviceState *)rtc_state, NULL);
+        object_property_add_child(object_resolve_path("/i440fx/piix3", NULL),
+                                  "rtc", (Object *)rtc_state, NULL);
     } else {
         for(i = 0; i < MAX_IDE_BUS; i++) {
             ISADevice *dev;
diff --git a/hw/piix_pci.c b/hw/piix_pci.c
index 2bbfa4a..1906427 100644
--- a/hw/piix_pci.c
+++ b/hw/piix_pci.c
@@ -277,7 +277,7 @@  static PCIBus *i440fx_common_init(const char *device_name,
                     address_space_io, 0);
     s->bus = b;
     qdev_init_nofail(dev);
-    qdev_property_add_child(qdev_get_root(), "i440fx", dev, NULL);
+    object_property_add_child(object_get_root(), "i440fx", OBJECT(dev), NULL);
 
     d = pci_create_simple(b, 0, device_name);
     *pi440fx_state = DO_UPCAST(PCII440FXState, dev, d);
@@ -316,7 +316,7 @@  static PCIBus *i440fx_common_init(const char *device_name,
         pci_bus_irqs(b, piix3_set_irq, pci_slot_get_pirq, piix3,
                 PIIX_NUM_PIRQS);
     }
-    qdev_property_add_child(dev, "piix3", &piix3->dev.qdev, NULL);
+    object_property_add_child(OBJECT(dev), "piix3", OBJECT(piix3), NULL);
     piix3->pic = pic;
     *isa_bus = DO_UPCAST(ISABus, qbus,
                          qdev_get_child_bus(&piix3->dev.qdev, "isa.0"));
diff --git a/hw/qdev-addr.c b/hw/qdev-addr.c
index 5ddda2d..5976dcd 100644
--- a/hw/qdev-addr.c
+++ b/hw/qdev-addr.c
@@ -18,9 +18,10 @@  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,
+static void get_taddr(Object *obj, Visitor *v, void *opaque,
                       const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     target_phys_addr_t *ptr = qdev_get_prop_ptr(dev, prop);
     int64_t value;
@@ -29,9 +30,10 @@  static void get_taddr(DeviceState *dev, Visitor *v, void *opaque,
     visit_type_int(v, &value, name, errp);
 }
 
-static void set_taddr(DeviceState *dev, Visitor *v, void *opaque,
+static void set_taddr(Object *obj, Visitor *v, void *opaque,
                       const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     target_phys_addr_t *ptr = qdev_get_prop_ptr(dev, prop);
     Error *local_err = NULL;
diff --git a/hw/qdev-monitor.c b/hw/qdev-monitor.c
index 3894574..46946fe 100644
--- a/hw/qdev-monitor.c
+++ b/hw/qdev-monitor.c
@@ -175,30 +175,32 @@  int qdev_device_help(QemuOpts *opts)
     return 1;
 }
 
-static DeviceState *qdev_get_peripheral(void)
+static Object *qdev_get_peripheral(void)
 {
     static DeviceState *dev;
 
     if (dev == NULL) {
         dev = qdev_create(NULL, "container");
-        qdev_property_add_child(qdev_get_root(), "peripheral", dev, NULL);
+        object_property_add_child(object_get_root(), "peripheral",
+                                  OBJECT(dev), NULL);
         qdev_init_nofail(dev);
     }
 
-    return dev;
+    return OBJECT(dev);
 }
 
-static DeviceState *qdev_get_peripheral_anon(void)
+static Object *qdev_get_peripheral_anon(void)
 {
     static DeviceState *dev;
 
     if (dev == NULL) {
         dev = qdev_create(NULL, "container");
-        qdev_property_add_child(qdev_get_root(), "peripheral-anon", dev, NULL);
+        object_property_add_child(object_get_root(), "peripheral-anon",
+                                  OBJECT(dev), NULL);
         qdev_init_nofail(dev);
     }
 
-    return dev;
+    return OBJECT(dev);
 }
 
 static void qbus_list_bus(DeviceState *dev)
@@ -457,12 +459,13 @@  DeviceState *qdev_device_add(QemuOpts *opts)
     id = qemu_opts_id(opts);
     if (id) {
         qdev->id = id;
-        qdev_property_add_child(qdev_get_peripheral(), qdev->id, qdev, NULL);
+        object_property_add_child(qdev_get_peripheral(), qdev->id,
+                                  OBJECT(qdev), NULL);
     } else {
         static int anon_count;
         gchar *name = g_strdup_printf("device[%d]", anon_count++);
-        qdev_property_add_child(qdev_get_peripheral_anon(), name,
-                                qdev, NULL);
+        object_property_add_child(qdev_get_peripheral_anon(), name,
+                                  OBJECT(qdev), NULL);
         g_free(name);
     }        
     if (qemu_opt_foreach(opts, set_property, qdev, 1) != 0) {
diff --git a/hw/qdev-properties.c b/hw/qdev-properties.c
index 724dce5..d34df30 100644
--- a/hw/qdev-properties.c
+++ b/hw/qdev-properties.c
@@ -55,9 +55,10 @@  static int print_bit(DeviceState *dev, Property *prop, char *dest, size_t len)
     return snprintf(dest, len, (*p & qdev_get_prop_mask(prop)) ? "on" : "off");
 }
 
-static void get_bit(DeviceState *dev, Visitor *v, void *opaque,
+static void get_bit(Object *obj, Visitor *v, void *opaque,
                     const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     uint32_t *p = qdev_get_prop_ptr(dev, prop);
     bool value = (*p & qdev_get_prop_mask(prop)) != 0;
@@ -65,9 +66,10 @@  static void get_bit(DeviceState *dev, Visitor *v, void *opaque,
     visit_type_bool(v, &value, name, errp);
 }
 
-static void set_bit(DeviceState *dev, Visitor *v, void *opaque,
+static void set_bit(Object *obj, Visitor *v, void *opaque,
                     const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     Error *local_err = NULL;
     bool value;
@@ -118,9 +120,10 @@  static int print_uint8(DeviceState *dev, Property *prop, char *dest, size_t len)
     return snprintf(dest, len, "%" PRIu8, *ptr);
 }
 
-static void get_int8(DeviceState *dev, Visitor *v, void *opaque,
+static void get_int8(Object *obj, Visitor *v, void *opaque,
                      const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     int8_t *ptr = qdev_get_prop_ptr(dev, prop);
     int64_t value;
@@ -129,9 +132,10 @@  static void get_int8(DeviceState *dev, Visitor *v, void *opaque,
     visit_type_int(v, &value, name, errp);
 }
 
-static void set_int8(DeviceState *dev, Visitor *v, void *opaque,
-                      const char *name, Error **errp)
+static void set_int8(Object *obj, Visitor *v, void *opaque,
+                     const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     int8_t *ptr = qdev_get_prop_ptr(dev, prop);
     Error *local_err = NULL;
@@ -224,9 +228,10 @@  static int print_uint16(DeviceState *dev, Property *prop, char *dest, size_t len
     return snprintf(dest, len, "%" PRIu16, *ptr);
 }
 
-static void get_int16(DeviceState *dev, Visitor *v, void *opaque,
+static void get_int16(Object *obj, Visitor *v, void *opaque,
                       const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     int16_t *ptr = qdev_get_prop_ptr(dev, prop);
     int64_t value;
@@ -235,9 +240,10 @@  static void get_int16(DeviceState *dev, Visitor *v, void *opaque,
     visit_type_int(v, &value, name, errp);
 }
 
-static void set_int16(DeviceState *dev, Visitor *v, void *opaque,
+static void set_int16(Object *obj, Visitor *v, void *opaque,
                       const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     int16_t *ptr = qdev_get_prop_ptr(dev, prop);
     Error *local_err = NULL;
@@ -296,9 +302,10 @@  static int print_uint32(DeviceState *dev, Property *prop, char *dest, size_t len
     return snprintf(dest, len, "%" PRIu32, *ptr);
 }
 
-static void get_int32(DeviceState *dev, Visitor *v, void *opaque,
+static void get_int32(Object *obj, Visitor *v, void *opaque,
                       const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     int32_t *ptr = qdev_get_prop_ptr(dev, prop);
     int64_t value;
@@ -307,9 +314,10 @@  static void get_int32(DeviceState *dev, Visitor *v, void *opaque,
     visit_type_int(v, &value, name, errp);
 }
 
-static void set_int32(DeviceState *dev, Visitor *v, void *opaque,
+static void set_int32(Object *obj, Visitor *v, void *opaque,
                       const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     int32_t *ptr = qdev_get_prop_ptr(dev, prop);
     Error *local_err = NULL;
@@ -433,18 +441,20 @@  static int print_uint64(DeviceState *dev, Property *prop, char *dest, size_t len
     return snprintf(dest, len, "%" PRIu64, *ptr);
 }
 
-static void get_int64(DeviceState *dev, Visitor *v, void *opaque,
+static void get_int64(Object *obj, Visitor *v, void *opaque,
                       const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     int64_t *ptr = qdev_get_prop_ptr(dev, prop);
 
     visit_type_int(v, ptr, name, errp);
 }
 
-static void set_int64(DeviceState *dev, Visitor *v, void *opaque,
+static void set_int64(Object *obj, Visitor *v, void *opaque,
                       const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     int64_t *ptr = qdev_get_prop_ptr(dev, prop);
 
@@ -523,9 +533,10 @@  static int print_string(DeviceState *dev, Property *prop, char *dest, size_t len
     return snprintf(dest, len, "\"%s\"", *ptr);
 }
 
-static void get_string(DeviceState *dev, Visitor *v, void *opaque,
+static void get_string(Object *obj, Visitor *v, void *opaque,
                        const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     char **ptr = qdev_get_prop_ptr(dev, prop);
 
@@ -537,9 +548,10 @@  static void get_string(DeviceState *dev, Visitor *v, void *opaque,
     }
 }
 
-static void set_string(DeviceState *dev, Visitor *v, void *opaque,
+static void set_string(Object *obj, Visitor *v, void *opaque,
                        const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     char **ptr = qdev_get_prop_ptr(dev, prop);
     Error *local_err = NULL;
@@ -609,9 +621,10 @@  static int print_drive(DeviceState *dev, Property *prop, char *dest, size_t len)
                     *ptr ? bdrv_get_device_name(*ptr) : "<null>");
 }
 
-static void get_generic(DeviceState *dev, Visitor *v, void *opaque,
+static void get_generic(Object *obj, Visitor *v, void *opaque,
                        const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     void **ptr = qdev_get_prop_ptr(dev, prop);
     char buffer[1024];
@@ -624,9 +637,10 @@  static void get_generic(DeviceState *dev, Visitor *v, void *opaque,
     visit_type_str(v, &p, name, errp);
 }
 
-static void set_generic(DeviceState *dev, Visitor *v, void *opaque,
+static void set_generic(Object *obj, Visitor *v, void *opaque,
                         const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     Error *local_err = NULL;
     char *str;
@@ -774,9 +788,10 @@  static int print_vlan(DeviceState *dev, Property *prop, char *dest, size_t len)
     }
 }
 
-static void get_vlan(DeviceState *dev, Visitor *v, void *opaque,
+static void get_vlan(Object *obj, Visitor *v, void *opaque,
                      const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     VLANState **ptr = qdev_get_prop_ptr(dev, prop);
     int64_t id;
@@ -785,9 +800,10 @@  static void get_vlan(DeviceState *dev, Visitor *v, void *opaque,
     visit_type_int(v, &id, name, errp);
 }
 
-static void set_vlan(DeviceState *dev, Visitor *v, void *opaque,
+static void set_vlan(Object *obj, Visitor *v, void *opaque,
                      const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     VLANState **ptr = qdev_get_prop_ptr(dev, prop);
     Error *local_err = NULL;
@@ -922,9 +938,10 @@  static int print_pci_devfn(DeviceState *dev, Property *prop, char *dest, size_t
     }
 }
 
-static void get_pci_devfn(DeviceState *dev, Visitor *v, void *opaque,
+static void get_pci_devfn(Object *obj, Visitor *v, void *opaque,
                           const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     uint32_t *ptr = qdev_get_prop_ptr(dev, prop);
     char buffer[32];
diff --git a/hw/qdev.c b/hw/qdev.c
index 0692a21..91dbbc7 100644
--- a/hw/qdev.c
+++ b/hw/qdev.c
@@ -243,46 +243,6 @@  void qdev_init_nofail(DeviceState *dev)
     }
 }
 
-static void qdev_property_del_all(DeviceState *dev)
-{
-    while (!QTAILQ_EMPTY(&dev->properties)) {
-        DeviceProperty *prop = QTAILQ_FIRST(&dev->properties);
-
-        QTAILQ_REMOVE(&dev->properties, prop, node);
-
-        if (prop->release) {
-            prop->release(dev, prop->name, prop->opaque);
-        }
-
-        g_free(prop->name);
-        g_free(prop->type);
-        g_free(prop);
-    }
-}
-
-static void qdev_property_del_child(DeviceState *dev, DeviceState *child, Error **errp)
-{
-    DeviceProperty *prop;
-
-    QTAILQ_FOREACH(prop, &dev->properties, node) {
-        if (strstart(prop->type, "child<", NULL) && prop->opaque == child) {
-            break;
-        }
-    }
-
-    g_assert(prop != NULL);
-
-    QTAILQ_REMOVE(&dev->properties, prop, node);
-
-    if (prop->release) {
-        prop->release(dev, prop->name, prop->opaque);
-    }
-
-    g_free(prop->name);
-    g_free(prop->type);
-    g_free(prop);
-}
-
 /* Unlink device from bus and free the structure.  */
 void qdev_free(DeviceState *dev)
 {
@@ -290,8 +250,6 @@  void qdev_free(DeviceState *dev)
     Property *prop;
     DeviceClass *dc = DEVICE_GET_CLASS(dev);
 
-    qdev_property_del_all(dev);
-
     if (dev->state == DEV_STATE_INITIALIZED) {
         while (dev->num_child_bus) {
             bus = QLIST_FIRST(&dev->child_bus);
@@ -313,12 +271,6 @@  void qdev_free(DeviceState *dev)
             prop->info->free(dev, prop);
         }
     }
-    if (dev->parent) {
-        qdev_property_del_child(dev->parent, dev, NULL);
-    }
-    if (dev->ref != 0) {
-        qerror_report(QERR_DEVICE_IN_USE, dev->id?:"");
-    }
     object_delete(OBJECT(dev));
 }
 
@@ -569,106 +521,19 @@  char* qdev_get_fw_dev_path(DeviceState *dev)
     return strdup(path);
 }
 
-char *qdev_get_type(DeviceState *dev, Error **errp)
-{
-    return g_strdup(object_get_typename(OBJECT(dev)));
-}
-
-void qdev_ref(DeviceState *dev)
+static char *qdev_get_type(Object *obj, Error **errp)
 {
-    dev->ref++;
-}
-
-void qdev_unref(DeviceState *dev)
-{
-    g_assert(dev->ref > 0);
-    dev->ref--;
-}
-
-void qdev_property_add(DeviceState *dev, const char *name, const char *type,
-                       DevicePropertyAccessor *get, DevicePropertyAccessor *set,
-                       DevicePropertyRelease *release,
-                       void *opaque, Error **errp)
-{
-    DeviceProperty *prop = g_malloc0(sizeof(*prop));
-
-    prop->name = g_strdup(name);
-    prop->type = g_strdup(type);
-
-    prop->get = get;
-    prop->set = set;
-    prop->release = release;
-    prop->opaque = opaque;
-
-    QTAILQ_INSERT_TAIL(&dev->properties, prop, node);
-}
-
-static DeviceProperty *qdev_property_find(DeviceState *dev, const char *name)
-{
-    DeviceProperty *prop;
-
-    QTAILQ_FOREACH(prop, &dev->properties, node) {
-        if (strcmp(prop->name, name) == 0) {
-            return prop;
-        }
-    }
-
-    return NULL;
-}
-
-void qdev_property_get(DeviceState *dev, Visitor *v, const char *name,
-                       Error **errp)
-{
-    DeviceProperty *prop = qdev_property_find(dev, name);
-
-    if (prop == NULL) {
-        error_set(errp, QERR_PROPERTY_NOT_FOUND, dev->id?:"", name);
-        return;
-    }
-
-    if (!prop->get) {
-        error_set(errp, QERR_PERMISSION_DENIED);
-    } else {
-        prop->get(dev, v, prop->opaque, name, errp);
-    }
-}
-
-void qdev_property_set(DeviceState *dev, Visitor *v, const char *name,
-                       Error **errp)
-{
-    DeviceProperty *prop = qdev_property_find(dev, name);
-
-    if (prop == NULL) {
-        error_set(errp, QERR_PROPERTY_NOT_FOUND, dev->id?:"", name);
-        return;
-    }
-
-    if (!prop->set) {
-        error_set(errp, QERR_PERMISSION_DENIED);
-    } else {
-        prop->set(dev, v, prop->opaque, name, errp);
-    }
-}
-
-const char *qdev_property_get_type(DeviceState *dev, const char *name, Error **errp)
-{
-    DeviceProperty *prop = qdev_property_find(dev, name);
-
-    if (prop == NULL) {
-        error_set(errp, QERR_PROPERTY_NOT_FOUND, dev->id?:"", name);
-        return NULL;
-    }
-
-    return prop->type;
+    return g_strdup(object_get_typename(obj));
 }
 
 /**
  * Legacy property handling
  */
 
-static void qdev_get_legacy_property(DeviceState *dev, Visitor *v, void *opaque,
+static void qdev_get_legacy_property(Object *obj, Visitor *v, void *opaque,
                                      const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
 
     char buffer[1024];
@@ -678,9 +543,10 @@  static void qdev_get_legacy_property(DeviceState *dev, Visitor *v, void *opaque,
     visit_type_str(v, &ptr, name, errp);
 }
 
-static void qdev_set_legacy_property(DeviceState *dev, Visitor *v, void *opaque,
+static void qdev_set_legacy_property(Object *obj, Visitor *v, void *opaque,
                                      const char *name, Error **errp)
 {
+    DeviceState *dev = DEVICE(obj);
     Property *prop = opaque;
     Error *local_err = NULL;
     char *ptr = NULL;
@@ -720,11 +586,11 @@  void qdev_property_add_legacy(DeviceState *dev, Property *prop,
     type = g_strdup_printf("legacy<%s>",
                            prop->info->legacy_name ?: prop->info->name);
 
-    qdev_property_add(dev, name, type,
-                      prop->info->print ? qdev_get_legacy_property : NULL,
-                      prop->info->parse ? qdev_set_legacy_property : NULL,
-                      NULL,
-                      prop, errp);
+    object_property_add(OBJECT(dev), name, type,
+                        prop->info->print ? qdev_get_legacy_property : NULL,
+                        prop->info->parse ? qdev_set_legacy_property : NULL,
+                        NULL,
+                        prop, errp);
 
     g_free(type);
     g_free(name);
@@ -739,333 +605,10 @@  void qdev_property_add_legacy(DeviceState *dev, Property *prop,
 void qdev_property_add_static(DeviceState *dev, Property *prop,
                               Error **errp)
 {
-    qdev_property_add(dev, prop->name, prop->info->name,
-                      prop->info->get, prop->info->set,
-                      NULL,
-                      prop, errp);
-}
-
-DeviceState *qdev_get_root(void)
-{
-    static DeviceState *qdev_root;
-
-    if (!qdev_root) {
-        qdev_root = qdev_create(NULL, "container");
-        qdev_init_nofail(qdev_root);
-    }
-
-    return qdev_root;
-}
-
-static void qdev_get_child_property(DeviceState *dev, Visitor *v, void *opaque,
-                                    const char *name, Error **errp)
-{
-    DeviceState *child = opaque;
-    gchar *path;
-
-    path = qdev_get_canonical_path(child);
-    visit_type_str(v, &path, name, errp);
-    g_free(path);
-}
-
-static void qdev_release_child_property(DeviceState *dev, const char *name,
-                                        void *opaque)
-{
-    DeviceState *child = opaque;
-
-    qdev_unref(child);
-}
-
-void qdev_property_add_child(DeviceState *dev, const char *name,
-                             DeviceState *child, Error **errp)
-{
-    gchar *type;
-
-    type = g_strdup_printf("child<%s>", object_get_typename(OBJECT(child)));
-
-    qdev_property_add(dev, name, type, qdev_get_child_property,
-                      NULL, qdev_release_child_property,
-                      child, errp);
-
-    qdev_ref(child);
-    g_assert(child->parent == NULL);
-    child->parent = dev;
-
-    g_free(type);
-}
-
-static void qdev_get_link_property(DeviceState *dev, Visitor *v, void *opaque,
-                                   const char *name, Error **errp)
-{
-    DeviceState **child = opaque;
-    gchar *path;
-
-    if (*child) {
-        path = qdev_get_canonical_path(*child);
-        visit_type_str(v, &path, name, errp);
-        g_free(path);
-    } else {
-        path = (gchar *)"";
-        visit_type_str(v, &path, name, errp);
-    }
-}
-
-static void qdev_set_link_property(DeviceState *dev, Visitor *v, void *opaque,
-                                   const char *name, Error **errp)
-{
-    DeviceState **child = opaque;
-    bool ambiguous = false;
-    const char *type;
-    char *path;
-
-    type = qdev_property_get_type(dev, name, NULL);
-
-    visit_type_str(v, &path, name, errp);
-
-    if (*child) {
-        qdev_unref(*child);
-    }
-
-    if (strcmp(path, "") != 0) {
-        DeviceState *target;
-
-        target = qdev_resolve_path(path, &ambiguous);
-        if (target) {
-            gchar *target_type;
-
-            target_type = g_strdup_printf("link<%s>", object_get_typename(OBJECT(target)));
-            if (strcmp(target_type, type) == 0) {
-                *child = target;
-                qdev_ref(target);
-            } else {
-                error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, type);
-            }
-
-            g_free(target_type);
-        } else {
-            error_set(errp, QERR_DEVICE_NOT_FOUND, path);
-        }
-    } else {
-        *child = NULL;
-    }
-
-    g_free(path);
-}
-
-void qdev_property_add_link(DeviceState *dev, const char *name,
-                            const char *type, DeviceState **child,
-                            Error **errp)
-{
-    gchar *full_type;
-
-    full_type = g_strdup_printf("link<%s>", type);
-
-    qdev_property_add(dev, name, full_type,
-                      qdev_get_link_property,
-                      qdev_set_link_property,
-                      NULL, child, errp);
-
-    g_free(full_type);
-}
-
-gchar *qdev_get_canonical_path(DeviceState *dev)
-{
-    DeviceState *root = qdev_get_root();
-    char *newpath = NULL, *path = NULL;
-
-    while (dev != root) {
-        DeviceProperty *prop = NULL;
-
-        g_assert(dev->parent != NULL);
-
-        QTAILQ_FOREACH(prop, &dev->parent->properties, node) {
-            if (!strstart(prop->type, "child<", NULL)) {
-                continue;
-            }
-
-            if (prop->opaque == dev) {
-                if (path) {
-                    newpath = g_strdup_printf("%s/%s", prop->name, path);
-                    g_free(path);
-                    path = newpath;
-                } else {
-                    path = g_strdup(prop->name);
-                }
-                break;
-            }
-        }
-
-        g_assert(prop != NULL);
-
-        dev = dev->parent;
-    }
-
-    newpath = g_strdup_printf("/%s", path);
-    g_free(path);
-
-    return newpath;
-}
-
-static DeviceState *qdev_resolve_abs_path(DeviceState *parent,
-                                          gchar **parts,
-                                          int index)
-{
-    DeviceProperty *prop;
-    DeviceState *child;
-
-    if (parts[index] == NULL) {
-        return parent;
-    }
-
-    if (strcmp(parts[index], "") == 0) {
-        return qdev_resolve_abs_path(parent, parts, index + 1);
-    }
-
-    prop = qdev_property_find(parent, parts[index]);
-    if (prop == NULL) {
-        return NULL;
-    }
-
-    child = NULL;
-    if (strstart(prop->type, "link<", NULL)) {
-        DeviceState **pchild = prop->opaque;
-        if (*pchild) {
-            child = *pchild;
-        }
-    } else if (strstart(prop->type, "child<", NULL)) {
-        child = prop->opaque;
-    }
-
-    if (!child) {
-        return NULL;
-    }
-
-    return qdev_resolve_abs_path(child, parts, index + 1);
-}
-
-static DeviceState *qdev_resolve_partial_path(DeviceState *parent,
-                                              gchar **parts,
-                                              bool *ambiguous)
-{
-    DeviceState *dev;
-    DeviceProperty *prop;
-
-    dev = qdev_resolve_abs_path(parent, parts, 0);
-
-    QTAILQ_FOREACH(prop, &parent->properties, node) {
-        DeviceState *found;
-
-        if (!strstart(prop->type, "child<", NULL)) {
-            continue;
-        }
-
-        found = qdev_resolve_partial_path(prop->opaque, parts, ambiguous);
-        if (found) {
-            if (dev) {
-                if (ambiguous) {
-                    *ambiguous = true;
-                }
-                return NULL;
-            }
-            dev = found;
-        }
-
-        if (ambiguous && *ambiguous) {
-            return NULL;
-        }
-    }
-
-    return dev;
-}
-
-DeviceState *qdev_resolve_path(const char *path, bool *ambiguous)
-{
-    bool partial_path = true;
-    DeviceState *dev;
-    gchar **parts;
-
-    parts = g_strsplit(path, "/", 0);
-    if (parts == NULL || parts[0] == NULL) {
-        g_strfreev(parts);
-        return qdev_get_root();
-    }
-
-    if (strcmp(parts[0], "") == 0) {
-        partial_path = false;
-    }
-
-    if (partial_path) {
-        if (ambiguous) {
-            *ambiguous = false;
-        }
-        dev = qdev_resolve_partial_path(qdev_get_root(), parts, ambiguous);
-    } else {
-        dev = qdev_resolve_abs_path(qdev_get_root(), parts, 1);
-    }
-
-    g_strfreev(parts);
-
-    return dev;
-}
-
-typedef struct StringProperty
-{
-    char *(*get)(DeviceState *, Error **);
-    void (*set)(DeviceState *, const char *, Error **);
-} StringProperty;
-
-static void qdev_property_get_str(DeviceState *dev, Visitor *v, void *opaque,
-                                  const char *name, Error **errp)
-{
-    StringProperty *prop = opaque;
-    char *value;
-
-    value = prop->get(dev, errp);
-    if (value) {
-        visit_type_str(v, &value, name, errp);
-        g_free(value);
-    }
-}
-
-static void qdev_property_set_str(DeviceState *dev, Visitor *v, void *opaque,
-                                  const char *name, Error **errp)
-{
-    StringProperty *prop = opaque;
-    char *value;
-    Error *local_err = NULL;
-
-    visit_type_str(v, &value, name, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
-        return;
-    }
-
-    prop->set(dev, value, errp);
-    g_free(value);
-}
-
-static void qdev_property_release_str(DeviceState *dev, const char *name,
-                                      void *opaque)
-{
-    StringProperty *prop = opaque;
-    g_free(prop);
-}
-
-void qdev_property_add_str(DeviceState *dev, const char *name,
-                           char *(*get)(DeviceState *, Error **),
-                           void (*set)(DeviceState *, const char *, Error **),
-                           Error **errp)
-{
-    StringProperty *prop = g_malloc0(sizeof(*prop));
-
-    prop->get = get;
-    prop->set = set;
-
-    qdev_property_add(dev, name, "string",
-                      get ? qdev_property_get_str : NULL,
-                      set ? qdev_property_set_str : NULL,
-                      qdev_property_release_str,
-                      prop, errp);
+    object_property_add(OBJECT(dev), prop->name, prop->info->name,
+                        prop->info->get, prop->info->set,
+                        NULL,
+                        prop, errp);
 }
 
 static void device_initfn(Object *obj)
@@ -1079,7 +622,6 @@  static void device_initfn(Object *obj)
     }
 
     dev->instance_id_alias = -1;
-    QTAILQ_INIT(&dev->properties);
     dev->state = DEV_STATE_CREATED;
 
     qdev_prop_set_defaults(dev, qdev_get_props(dev));
@@ -1088,7 +630,7 @@  static void device_initfn(Object *obj)
         qdev_property_add_static(dev, prop, NULL);
     }
 
-    qdev_property_add_str(dev, "type", qdev_get_type, NULL, NULL);
+    object_property_add_str(OBJECT(dev), "type", qdev_get_type, NULL, NULL);
 }
 
 void device_reset(DeviceState *dev)
diff --git a/hw/qdev.h b/hw/qdev.h
index d1f0e19..1d9143f 100644
--- a/hw/qdev.h
+++ b/hw/qdev.h
@@ -27,44 +27,6 @@  enum {
     DEV_NVECTORS_UNSPECIFIED = -1,
 };
 
-/**
- * @DevicePropertyAccessor - called when trying to get/set a property
- *
- * @dev the device that owns the property
- * @v the visitor that contains the property data
- * @opaque the device property opaque
- * @name the name of the property
- * @errp a pointer to an Error that is filled if getting/setting fails.
- */
-typedef void (DevicePropertyAccessor)(DeviceState *dev,
-                                      Visitor *v,
-                                      void *opaque,
-                                      const char *name,
-                                      Error **errp);
-
-/**
- * @DevicePropertyRelease - called when a property is removed from a device
- *
- * @dev the device that owns the property
- * @name the name of the property
- * @opaque the opaque registered with the property
- */
-typedef void (DevicePropertyRelease)(DeviceState *dev,
-                                     const char *name,
-                                     void *opaque);
-
-typedef struct DeviceProperty
-{
-    gchar *name;
-    gchar *type;
-    DevicePropertyAccessor *get;
-    DevicePropertyAccessor *set;
-    DevicePropertyRelease *release;
-    void *opaque;
-
-    QTAILQ_ENTRY(DeviceProperty) node;
-} DeviceProperty;
-
 #define TYPE_DEVICE "device"
 #define DEVICE(obj) OBJECT_CHECK(DeviceState, (obj), TYPE_DEVICE)
 #define DEVICE_CLASS(klass) OBJECT_CLASS_CHECK(DeviceClass, (klass), TYPE_DEVICE)
@@ -114,18 +76,6 @@  struct DeviceState {
     QTAILQ_ENTRY(DeviceState) sibling;
     int instance_id_alias;
     int alias_required_for_version;
-
-    /**
-     * This tracks the number of references between devices.  See @qdev_ref for
-     * more information.
-     */
-    uint32_t ref;
-
-    QTAILQ_HEAD(, DeviceProperty) properties;
-
-    /* Do not, under any circumstance, use this parent link below anywhere
-     * outside of qdev.c.  You have been warned. */
-    DeviceState *parent;
 };
 
 typedef void (*bus_dev_printfn)(Monitor *mon, DeviceState *dev, int indent);
@@ -194,8 +144,8 @@  struct PropertyInfo {
     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;
+    ObjectPropertyAccessor *get;
+    ObjectPropertyAccessor *set;
 };
 
 typedef struct GlobalProperty {
@@ -383,235 +333,12 @@  char *qdev_get_fw_dev_path(DeviceState *dev);
 extern struct BusInfo system_bus_info;
 
 /**
- * @qdev_ref
- *
- * Increase the reference count of a device.  A device cannot be freed as long
- * as its reference count is greater than zero.
- *
- * @dev - the device
- */
-void qdev_ref(DeviceState *dev);
-
-/**
- * @qdef_unref
- *
- * Decrease the reference count of a device.  A device cannot be freed as long
- * as its reference count is greater than zero.
- *
- * @dev - the device
- */
-void qdev_unref(DeviceState *dev);
-
-/**
- * @qdev_property_add - add a new property to a device
- *
- * @dev - the device to add a property to
- *
- * @name - the name of the property.  This can contain any character except for
- *         a forward slash.  In general, you should use hyphens '-' instead of
- *         underscores '_' when naming properties.
- *
- * @type - the type name of the property.  This namespace is pretty loosely
- *         defined.  Sub namespaces are constructed by using a prefix and then
- *         to angle brackets.  For instance, the type 'virtio-net-pci' in the
- *         'link' namespace would be 'link<virtio-net-pci>'.
- *
- * @get - the getter to be called to read a property.  If this is NULL, then
- *        the property cannot be read.
- *
- * @set - the setter to be called to write a property.  If this is NULL,
- *        then the property cannot be written.
- *
- * @release - called when the property is removed from the device.  This is
- *            meant to allow a property to free its opaque upon device
- *            destruction.  This may be NULL.
- *
- * @opaque - an opaque pointer to pass to the callbacks for the property
- *
- * @errp - returns an error if this function fails
- */
-void qdev_property_add(DeviceState *dev, const char *name, const char *type,
-                       DevicePropertyAccessor *get, DevicePropertyAccessor *set,
-                       DevicePropertyRelease *release,
-                       void *opaque, Error **errp);
-
-/**
- * @qdev_property_get - reads a property from a device
- *
- * @dev - the device
- *
- * @v - the visitor that will receive the property value.  This should be an
- *      Output visitor and the data will be written with @name as the name.
- *
- * @name - the name of the property
- *
- * @errp - returns an error if this function fails
- */
-void qdev_property_get(DeviceState *dev, Visitor *v, const char *name,
-                       Error **errp);
-
-/**
- * @qdev_property_set - writes a property to a device
- *
- * @dev - the device
- *
- * @v - the visitor that will be used to write the property value.  This should
- *      be an Input visitor and the data will be first read with @name as the
- *      name and then written as the property value.
- *
- * @name - the name of the property
- *
- * @errp - returns an error if this function fails
- */
-void qdev_property_set(DeviceState *dev, Visitor *v, const char *name,
-                       Error **errp);
-
-/**
- * @qdev_property_get_type - returns the type of a property
- *
- * @dev - the device
- *
- * @name - the name of the property
- *
- * @errp - returns an error if this function fails
- *
- * Returns:
- *   The type name of the property.
- */
-const char *qdev_property_get_type(DeviceState *dev, const char *name,
-                                   Error **errp);
-
-/**
  * @qdev_property_add_static - add a @Property to a device referencing a
  * field in a struct.
  */
 void qdev_property_add_static(DeviceState *dev, Property *prop, Error **errp);
 
 /**
- * @qdev_get_root - returns the root device of the composition tree
- *
- * Returns:
- *   The root of the composition tree.
- */
-DeviceState *qdev_get_root(void);
-
-/**
- * @qdev_get_canonical_path - returns the canonical path for a device.  This
- * is the path within the composition tree starting from the root.
- *
- * Returns:
- *   The canonical path in the composition tree.
- */
-gchar *qdev_get_canonical_path(DeviceState *dev);
-
-/**
- * @qdev_resolve_path - resolves a path returning a device
- *
- * There are two types of supported paths--absolute paths and partial paths.
- * 
- * Absolute paths are derived from the root device and can follow child<> or
- * link<> properties.  Since they can follow link<> properties, they can be
- * arbitrarily long.  Absolute paths look like absolute filenames and are
- * prefixed with a leading slash.
- * 
- * Partial paths look like relative filenames.  They do not begin with a
- * prefix.  The matching rules for partial paths are subtle but designed to make
- * specifying devices easy.  At each level of the composition tree, the partial
- * path is matched as an absolute path.  The first match is not returned.  At
- * least two matches are searched for.  A successful result is only returned if
- * only one match is founded.  If more than one match is found, a flag is
- * return to indicate that the match was ambiguous.
- *
- * @path - the path to resolve
- *
- * @ambiguous - returns true if the path resolution failed because of an
- *              ambiguous match
- *
- * Returns:
- *   The matched device or NULL on path lookup failure.
- */
-DeviceState *qdev_resolve_path(const char *path, bool *ambiguous);
-
-/**
- * @qdev_property_add_child - Add a child property to a device
- *
- * Child properties form the composition tree.  All devices need to be a child
- * of another device.  Devices can only be a child of one device.
- *
- * There is no way for a child to determine what its parent is.  It is not
- * a bidirectional relationship.  This is by design.
- *
- * @dev - the device to add a property to
- *
- * @name - the name of the property
- *
- * @child - the child device
- *
- * @errp - if an error occurs, a pointer to an area to store the area
- */
-void qdev_property_add_child(DeviceState *dev, const char *name,
-                             DeviceState *child, Error **errp);
-
-/**
- * @qdev_property_add_link - Add a link property to a device
- *
- * Links establish relationships between devices.  Links are unidirectional
- * although two links can be combined to form a bidirectional relationship
- * between devices.
- *
- * Links form the graph in the device model.
- *
- * @dev - the device to add a property to
- *
- * @name - the name of the property
- *
- * @type - the qdev type of the link
- *
- * @child - a pointer to where the link device reference is stored
- *
- * @errp - if an error occurs, a pointer to an area to store the area
- */
-void qdev_property_add_link(DeviceState *dev, const char *name,
-                            const char *type, DeviceState **child,
-                            Error **errp);
-
-/**
- * @qdev_property_add_str
- *
- * Add a string property using getters/setters.  This function will add a
- * property of type 'string'.
- *
- * @dev - the device to add a property to
- *
- * @name - the name of the property
- *
- * @get - the getter or NULL if the property is write-only.  This function must
- *        return a string to be freed by @g_free().
- *
- * @set - the setter or NULL if the property is read-only
- *
- * @errp - if an error occurs, a pointer to an area to store the error
- */
-void qdev_property_add_str(DeviceState *dev, const char *name,
-                           char *(*get)(DeviceState *, Error **),
-                           void (*set)(DeviceState *, const char *, Error **),
-                           Error **errp);
-
-/**
- * @qdev_get_type
- *
- * Returns the string representation of the type of this object.
- *
- * @dev - the device
- *
- * @errp - if an error occurs, a pointer to an area to store the error
- *
- * Returns: a string representing the type.  This must be freed by the caller
- *          with g_free().
- */
-char *qdev_get_type(DeviceState *dev, Error **errp);
-
-/**
  * @qdev_machine_init
  *
  * Initialize platform devices before machine init.  This is a hack until full
diff --git a/include/qemu/object.h b/include/qemu/object.h
index adbcfb1..b77584c 100644
--- a/include/qemu/object.h
+++ b/include/qemu/object.h
@@ -17,6 +17,10 @@ 
 #include <glib.h>
 #include <stdint.h>
 #include <stdbool.h>
+#include "qemu-queue.h"
+
+struct Visitor;
+struct Error;
 
 struct TypeImpl;
 typedef struct TypeImpl *Type;
@@ -114,6 +118,47 @@  typedef struct InterfaceInfo InterfaceInfo;
  * to one of its #Interface types and vice versa.
  */
 
+
+/**
+ * ObjectPropertyAccessor:
+ * @obj: the object that owns the property
+ * @v: the visitor that contains the property data
+ * @opaque: the object property opaque
+ * @name: the name of the property
+ * @errp: a pointer to an Error that is filled if getting/setting fails.
+ *
+ * Called when trying to get/set a property.
+ */
+typedef void (ObjectPropertyAccessor)(Object *obj,
+                                      struct Visitor *v,
+                                      void *opaque,
+                                      const char *name,
+                                      struct Error **errp);
+
+/**
+ * ObjectPropertyRelease:
+ * @obj: the object that owns the property
+ * @name: the name of the property
+ * @opaque: the opaque registered with the property
+ *
+ * Called when a property is removed from a object.
+ */
+typedef void (ObjectPropertyRelease)(Object *obj,
+                                     const char *name,
+                                     void *opaque);
+
+typedef struct ObjectProperty
+{
+    gchar *name;
+    gchar *type;
+    ObjectPropertyAccessor *get;
+    ObjectPropertyAccessor *set;
+    ObjectPropertyRelease *release;
+    void *opaque;
+
+    QTAILQ_ENTRY(ObjectProperty) node;
+} ObjectProperty;
+
 /**
  * ObjectClass:
  *
@@ -145,8 +190,10 @@  struct Object
 {
     /*< private >*/
     ObjectClass *class;
-
     GSList *interfaces;
+    QTAILQ_HEAD(, ObjectProperty) properties;
+    uint32_t ref;
+    Object *parent;
 };
 
 /**
@@ -433,5 +480,179 @@  ObjectClass *object_class_by_name(const char *typename);
 void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
                           const char *implements_type, bool include_abstract,
                           void *opaque);
+/**
+ * object_ref:
+ * @obj: the object
+ *
+ * Increase the reference count of a object.  A object cannot be freed as long
+ * as its reference count is greater than zero.
+ */
+void object_ref(Object *obj);
+
+/**
+ * qdef_unref:
+ * @obj: the object
+ *
+ * Decrease the reference count of a object.  A object cannot be freed as long
+ * as its reference count is greater than zero.
+ */
+void object_unref(Object *obj);
+
+/**
+ * object_property_add:
+ * @obj: the object to add a property to
+ * @name: the name of the property.  This can contain any character except for
+ *  a forward slash.  In general, you should use hyphens '-' instead of
+ *  underscores '_' when naming properties.
+ * @type: the type name of the property.  This namespace is pretty loosely
+ *   defined.  Sub namespaces are constructed by using a prefix and then
+ *   to angle brackets.  For instance, the type 'virtio-net-pci' in the
+ *   'link' namespace would be 'link<virtio-net-pci>'.
+ * @get: The getter to be called to read a property.  If this is NULL, then
+ *   the property cannot be read.
+ * @set: the setter to be called to write a property.  If this is NULL,
+ *   then the property cannot be written.
+ * @release: called when the property is removed from the object.  This is
+ *   meant to allow a property to free its opaque upon object
+ *   destruction.  This may be NULL.
+ * @opaque: an opaque pointer to pass to the callbacks for the property
+ * @errp: returns an error if this function fails
+ */
+void object_property_add(Object *obj, const char *name, const char *type,
+                         ObjectPropertyAccessor *get,
+                         ObjectPropertyAccessor *set,
+                         ObjectPropertyRelease *release,
+                         void *opaque, struct Error **errp);
+
+void object_property_del(Object *obj, const char *name, Error **errp);
+
+/**
+ * object_property_get:
+ * @obj: the object
+ * @v: the visitor that will receive the property value.  This should be an
+ *   Output visitor and the data will be written with @name as the name.
+ * @name: the name of the property
+ * @errp: returns an error if this function fails
+ *
+ * Reads a property from a object.
+ */
+void object_property_get(Object *obj, struct Visitor *v, const char *name,
+                         struct Error **errp);
+
+/**
+ * object_property_set:
+ * @obj: the object
+ * @v: the visitor that will be used to write the property value.  This should
+ *   be an Input visitor and the data will be first read with @name as the
+ *   name and then written as the property value.
+ * @name: the name of the property
+ * @errp: returns an error if this function fails
+ *
+ * Writes a property to a object.
+ */
+void object_property_set(Object *obj, struct Visitor *v, const char *name,
+                         struct Error **errp);
+
+/**
+ * @object_property_get_type:
+ * @obj: the object
+ * @name: the name of the property
+ * @errp: returns an error if this function fails
+ *
+ * Returns:  The type name of the property.
+ */
+const char *object_property_get_type(Object *obj, const char *name,
+                                     struct Error **errp);
+
+/**
+ * object_get_root:
+ *
+ * Returns: the root object of the composition tree
+ */
+Object *object_get_root(void);
+
+/**
+ * object_get_canonical_path:
+ *
+ * Returns: The canonical path for a object.  This is the path within the
+ * composition tree starting from the root.
+ */
+gchar *object_get_canonical_path(Object *obj);
+
+/**
+ * object_resolve_path:
+ * @path: the path to resolve
+ * @ambiguous: returns true if the path resolution failed because of an
+ *   ambiguous match
+ *
+ * There are two types of supported paths--absolute paths and partial paths.
+ * 
+ * Absolute paths are derived from the root object and can follow child<> or
+ * link<> properties.  Since they can follow link<> properties, they can be
+ * arbitrarily long.  Absolute paths look like absolute filenames and are
+ * prefixed with a leading slash.
+ * 
+ * Partial paths look like relative filenames.  They do not begin with a
+ * prefix.  The matching rules for partial paths are subtle but designed to make
+ * specifying objects easy.  At each level of the composition tree, the partial
+ * path is matched as an absolute path.  The first match is not returned.  At
+ * least two matches are searched for.  A successful result is only returned if
+ * only one match is founded.  If more than one match is found, a flag is
+ * return to indicate that the match was ambiguous.
+ *
+ * Returns: The matched object or NULL on path lookup failure.
+ */
+Object *object_resolve_path(const char *path, bool *ambiguous);
+
+/**
+ * object_property_add_child:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @child: the child object
+ * @errp: if an error occurs, a pointer to an area to store the area
+ *
+ * Child properties form the composition tree.  All objects need to be a child
+ * of another object.  Objects can only be a child of one object.
+ *
+ * There is no way for a child to determine what its parent is.  It is not
+ * a bidirectional relationship.  This is by design.
+ */
+void object_property_add_child(Object *obj, const char *name,
+                               Object *child, struct Error **errp);
+
+/**
+ * object_property_add_link:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @type: the qobj type of the link
+ * @child: a pointer to where the link object reference is stored
+ * @errp: if an error occurs, a pointer to an area to store the area
+ *
+ * Links establish relationships between objects.  Links are unidirectional
+ * although two links can be combined to form a bidirectional relationship
+ * between objects.
+ *
+ * Links form the graph in the object model.
+ */
+void object_property_add_link(Object *obj, const char *name,
+                              const char *type, Object **child,
+                              struct Error **errp);
+
+/**
+ * object_property_add_str:
+ * @obj: the object to add a property to
+ * @name: the name of the property
+ * @get: the getter or NULL if the property is write-only.  This function must
+ *   return a string to be freed by g_free().
+ * @set: the setter or NULL if the property is read-only
+ * @errp: if an error occurs, a pointer to an area to store the error
+ *
+ * Add a string property using getters/setters.  This function will add a
+ * property of type 'string'.
+ */
+void object_property_add_str(Object *obj, const char *name,
+                             char *(*get)(Object *, struct Error **),
+                             void (*set)(Object *, const char *, struct Error **),
+                             struct Error **errp);
 
 #endif
diff --git a/qapi-schema.json b/qapi-schema.json
index 56a4123..d02ee86 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1228,20 +1228,20 @@ 
 #
 # Notes: This type is experimental.  Its syntax may change in future releases.
 ##
-{ 'type': 'DevicePropertyInfo',
+{ 'type': 'ObjectPropertyInfo',
   'data': { 'name': 'str', 'type': 'str' } }
 
 ##
 # @qom-list:
 #
-# This command will list any properties of a device given a path in the device
+# This command will list any properties of a object given a path in the object
 # model.
 #
-# @path: the path within the device model.  See @qom-get for a description of
+# @path: the path within the object model.  See @qom-get for a description of
 #        this parameter.
 #
-# Returns: a list of @DevicePropertyInfo that describe the properties of the
-#          device.
+# Returns: a list of @ObjectPropertyInfo that describe the properties of the
+#          object.
 #
 # Since: 1.1
 #
@@ -1250,25 +1250,25 @@ 
 ##
 { 'command': 'qom-list',
   'data': { 'path': 'str' },
-  'returns': [ 'DevicePropertyInfo' ] }
+  'returns': [ 'ObjectPropertyInfo' ] }
 
 ##
 # @qom-get:
 #
-# This command will get a property from a device model path and return the
+# This command will get a property from a object model path and return the
 # value.
 #
-# @path: The path within the device model.  There are two forms of supported
+# @path: The path within the object model.  There are two forms of supported
 #        paths--absolute and partial paths.
 #
-#        Absolute paths are derived from the root device and can follow child<>
+#        Absolute paths are derived from the root object and can follow child<>
 #        or link<> properties.  Since they can follow link<> properties, they
 #        can be arbitrarily long.  Absolute paths look like absolute filenames
 #        and are prefixed  with a leading slash.
 #
 #        Partial paths look like relative filenames.  They do not begin
 #        with a prefix.  The matching rules for partial paths are subtle but
-#        designed to make specifying devices easy.  At each level of the
+#        designed to make specifying objects easy.  At each level of the
 #        composition tree, the partial path is matched as an absolute path.
 #        The first match is not returned.  At least two matches are searched
 #        for.  A successful result is only returned if only one match is
@@ -1294,7 +1294,7 @@ 
 ##
 # @qom-set:
 #
-# This command will set a property from a device model path.
+# This command will set a property from a object model path.
 #
 # @path: see @qom-get for a description of this parameter
 #
diff --git a/qmp.c b/qmp.c
index 75049ed..45052cc 100644
--- a/qmp.c
+++ b/qmp.c
@@ -164,23 +164,23 @@  void qmp_cont(Error **errp)
     vm_start();
 }
 
-DevicePropertyInfoList *qmp_qom_list(const char *path, Error **errp)
+ObjectPropertyInfoList *qmp_qom_list(const char *path, Error **errp)
 {
-    DeviceState *dev;
+    Object *obj;
     bool ambiguous = false;
-    DevicePropertyInfoList *props = NULL;
-    DeviceProperty *prop;
+    ObjectPropertyInfoList *props = NULL;
+    ObjectProperty *prop;
 
-    dev = qdev_resolve_path(path, &ambiguous);
-    if (dev == NULL) {
+    obj = object_resolve_path(path, &ambiguous);
+    if (obj == NULL) {
         error_set(errp, QERR_DEVICE_NOT_FOUND, path);
         return NULL;
     }
 
-    QTAILQ_FOREACH(prop, &dev->properties, node) {
-        DevicePropertyInfoList *entry = g_malloc0(sizeof(*entry));
+    QTAILQ_FOREACH(prop, &obj->properties, node) {
+        ObjectPropertyInfoList *entry = g_malloc0(sizeof(*entry));
 
-        entry->value = g_malloc0(sizeof(DevicePropertyInfo));
+        entry->value = g_malloc0(sizeof(ObjectPropertyInfo));
         entry->next = props;
         props = entry;
 
@@ -199,16 +199,16 @@  int qmp_qom_set(Monitor *mon, const QDict *qdict, QObject **ret)
     QObject *value = qdict_get(qdict, "value");
     Error *local_err = NULL;
     QmpInputVisitor *mi;
-    DeviceState *dev;
+    Object *obj;
 
-    dev = qdev_resolve_path(path, NULL);
-    if (!dev) {
+    obj = object_resolve_path(path, NULL);
+    if (!obj) {
         error_set(&local_err, QERR_DEVICE_NOT_FOUND, path);
         goto out;
     }
 
     mi = qmp_input_visitor_new(value);
-    qdev_property_set(dev, qmp_input_get_visitor(mi), property, &local_err);
+    object_property_set(obj, qmp_input_get_visitor(mi), property, &local_err);
 
     qmp_input_visitor_cleanup(mi);
 
@@ -228,16 +228,16 @@  int qmp_qom_get(Monitor *mon, const QDict *qdict, QObject **ret)
     const char *property = qdict_get_str(qdict, "property");
     Error *local_err = NULL;
     QmpOutputVisitor *mo;
-    DeviceState *dev;
+    Object *obj;
 
-    dev = qdev_resolve_path(path, NULL);
-    if (!dev) {
+    obj = object_resolve_path(path, NULL);
+    if (!obj) {
         error_set(&local_err, QERR_DEVICE_NOT_FOUND, path);
         goto out;
     }
 
     mo = qmp_output_visitor_new();
-    qdev_property_get(dev, qmp_output_get_visitor(mo), property, &local_err);
+    object_property_get(obj, qmp_output_get_visitor(mo), property, &local_err);
     if (!local_err) {
         *ret = qmp_output_get_qobject(mo);
     }
diff --git a/qom/object.c b/qom/object.c
index 3dabb1a..3133a62 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -12,6 +12,9 @@ 
 
 #include "qemu/object.h"
 #include "qemu-common.h"
+#include "qapi/qapi-visit-core.h"
+#include "hw/qdev.h"
+// FIXME remove above
 
 #define MAX_INTERFACES 32
 
@@ -258,6 +261,7 @@  void object_initialize_with_type(void *data, TypeImpl *type)
 
     memset(obj, 0, type->instance_size);
     obj->class = type->class;
+    QTAILQ_INIT(&obj->properties);
     object_init_with_type(obj, type);
 }
 
@@ -268,6 +272,38 @@  void object_initialize(void *data, const char *typename)
     object_initialize_with_type(data, type);
 }
 
+static void object_property_del_all(Object *obj)
+{
+    while (!QTAILQ_EMPTY(&obj->properties)) {
+        ObjectProperty *prop = QTAILQ_FIRST(&obj->properties);
+
+        QTAILQ_REMOVE(&obj->properties, prop, node);
+
+        if (prop->release) {
+            prop->release(obj, prop->name, prop->opaque);
+        }
+
+        g_free(prop->name);
+        g_free(prop->type);
+        g_free(prop);
+    }
+}
+
+static void object_property_del_child(Object *obj, Object *child, Error **errp)
+{
+    while (!QTAILQ_EMPTY(&obj->properties)) {
+        ObjectProperty *prop = QTAILQ_FIRST(&obj->properties);
+
+        if (!strstart(prop->type, "child<", NULL)) {
+            continue;
+        }
+
+        if (prop->opaque == child) {
+            object_property_del(obj, prop->name, errp);
+        }
+    }
+}
+
 static void object_deinit(Object *obj, TypeImpl *type)
 {
     if (type->instance_finalize) {
@@ -283,6 +319,9 @@  static void object_deinit(Object *obj, TypeImpl *type)
     if (type_has_parent(type)) {
         object_deinit(obj, type_get_parent(type));
     }
+    if (obj->parent) {
+        object_property_del_child(obj->parent, obj, NULL);
+    }
 }
 
 void object_finalize(void *data)
@@ -291,6 +330,7 @@  void object_finalize(void *data)
     TypeImpl *ti = obj->class->type;
 
     object_deinit(obj, ti);
+    object_property_del_all(obj);
 }
 
 Object *object_new_with_type(Type type)
@@ -502,3 +542,420 @@  void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
 
     g_hash_table_foreach(type_table_get(), object_class_foreach_tramp, &data);
 }
+
+void object_ref(Object *obj)
+{
+    obj->ref++;
+}
+
+void object_unref(Object *obj)
+{
+    g_assert(obj->ref > 0);
+    obj->ref--;
+}
+
+void object_property_add(Object *obj, const char *name, const char *type,
+                         ObjectPropertyAccessor *get,
+                         ObjectPropertyAccessor *set,
+                         ObjectPropertyRelease *release,
+                         void *opaque, Error **errp)
+{
+    ObjectProperty *prop = g_malloc0(sizeof(*prop));
+
+    prop->name = g_strdup(name);
+    prop->type = g_strdup(type);
+
+    prop->get = get;
+    prop->set = set;
+    prop->release = release;
+    prop->opaque = opaque;
+
+    QTAILQ_INSERT_TAIL(&obj->properties, prop, node);
+}
+
+static ObjectProperty *object_property_find(Object *obj, const char *name)
+{
+    ObjectProperty *prop;
+
+    QTAILQ_FOREACH(prop, &obj->properties, node) {
+        if (strcmp(prop->name, name) == 0) {
+            return prop;
+        }
+    }
+
+    return NULL;
+}
+
+void object_property_del(Object *obj, const char *name, Error **errp)
+{
+    ObjectProperty *prop = object_property_find(obj, name);
+
+    QTAILQ_REMOVE(&obj->properties, prop, node);
+
+    prop->release(obj, prop->name, prop->opaque);
+
+    g_free(prop->name);
+    g_free(prop->type);
+    g_free(prop);
+}
+
+void object_property_get(Object *obj, Visitor *v, const char *name,
+                         Error **errp)
+{
+    ObjectProperty *prop = object_property_find(obj, name);
+
+    if (prop == NULL) {
+        error_set(errp, QERR_PROPERTY_NOT_FOUND, "", name);
+        return;
+    }
+
+    if (!prop->get) {
+        error_set(errp, QERR_PERMISSION_DENIED);
+    } else {
+        prop->get(obj, v, prop->opaque, name, errp);
+    }
+}
+
+void object_property_set(Object *obj, Visitor *v, const char *name,
+                         Error **errp)
+{
+    ObjectProperty *prop = object_property_find(obj, name);
+
+    if (prop == NULL) {
+        error_set(errp, QERR_PROPERTY_NOT_FOUND, "", name);
+        return;
+    }
+
+    if (!prop->set) {
+        error_set(errp, QERR_PERMISSION_DENIED);
+    } else {
+        prop->set(obj, v, prop->opaque, name, errp);
+    }
+}
+
+const char *object_property_get_type(Object *obj, const char *name, Error **errp)
+{
+    ObjectProperty *prop = object_property_find(obj, name);
+
+    if (prop == NULL) {
+        error_set(errp, QERR_PROPERTY_NOT_FOUND, "", name);
+        return NULL;
+    }
+
+    return prop->type;
+}
+
+Object *object_get_root(void)
+{
+    static DeviceState *object_root;
+
+    if (!object_root) {
+        object_root = qdev_create(NULL, "container");
+        qdev_init_nofail(object_root);
+    }
+
+    return OBJECT(object_root);
+}
+
+static void object_get_child_property(Object *obj, Visitor *v, void *opaque,
+                                      const char *name, Error **errp)
+{
+    Object *child = opaque;
+    gchar *path;
+
+    path = object_get_canonical_path(child);
+    visit_type_str(v, &path, name, errp);
+    g_free(path);
+}
+
+void object_property_add_child(Object *obj, const char *name,
+                               Object *child, Error **errp)
+{
+    gchar *type;
+
+    type = g_strdup_printf("child<%s>", object_get_typename(OBJECT(child)));
+
+    object_property_add(obj, name, type, object_get_child_property,
+                        NULL, NULL, child, errp);
+
+    object_ref(child);
+    g_assert(child->parent == NULL);
+    child->parent = obj;
+
+    g_free(type);
+}
+
+static void object_get_link_property(Object *obj, Visitor *v, void *opaque,
+                                     const char *name, Error **errp)
+{
+    Object **child = opaque;
+    gchar *path;
+
+    if (*child) {
+        path = object_get_canonical_path(*child);
+        visit_type_str(v, &path, name, errp);
+        g_free(path);
+    } else {
+        path = (gchar *)"";
+        visit_type_str(v, &path, name, errp);
+    }
+}
+
+static void object_set_link_property(Object *obj, Visitor *v, void *opaque,
+                                     const char *name, Error **errp)
+{
+    Object **child = opaque;
+    bool ambiguous = false;
+    const char *type;
+    char *path;
+
+    type = object_property_get_type(obj, name, NULL);
+
+    visit_type_str(v, &path, name, errp);
+
+    if (*child) {
+        object_unref(*child);
+    }
+
+    if (strcmp(path, "") != 0) {
+        Object *target;
+
+        target = object_resolve_path(path, &ambiguous);
+        if (target) {
+            gchar *target_type;
+
+            target_type = g_strdup_printf("link<%s>",
+                                          object_get_typename(OBJECT(target)));
+            if (strcmp(target_type, type) == 0) {
+                *child = target;
+                object_ref(target);
+            } else {
+                error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, type);
+            }
+
+            g_free(target_type);
+        } else {
+            error_set(errp, QERR_DEVICE_NOT_FOUND, path);
+        }
+    } else {
+        *child = NULL;
+    }
+
+    g_free(path);
+}
+
+void object_property_add_link(Object *obj, const char *name,
+                              const char *type, Object **child,
+                              Error **errp)
+{
+    gchar *full_type;
+
+    full_type = g_strdup_printf("link<%s>", type);
+
+    object_property_add(obj, name, full_type,
+                        object_get_link_property,
+                        object_set_link_property,
+                        NULL, child, errp);
+
+    g_free(full_type);
+}
+
+gchar *object_get_canonical_path(Object *obj)
+{
+    Object *root = object_get_root();
+    char *newpath = NULL, *path = NULL;
+
+    while (obj != root) {
+        ObjectProperty *prop = NULL;
+
+        g_assert(obj->parent != NULL);
+
+        QTAILQ_FOREACH(prop, &obj->parent->properties, node) {
+            if (!strstart(prop->type, "child<", NULL)) {
+                continue;
+            }
+
+            if (prop->opaque == obj) {
+                if (path) {
+                    newpath = g_strdup_printf("%s/%s", prop->name, path);
+                    g_free(path);
+                    path = newpath;
+                } else {
+                    path = g_strdup(prop->name);
+                }
+                break;
+            }
+        }
+
+        g_assert(prop != NULL);
+
+        obj = obj->parent;
+    }
+
+    newpath = g_strdup_printf("/%s", path);
+    g_free(path);
+
+    return newpath;
+}
+
+static Object *object_resolve_abs_path(Object *parent,
+                                          gchar **parts,
+                                          int index)
+{
+    ObjectProperty *prop;
+    Object *child;
+
+    if (parts[index] == NULL) {
+        return parent;
+    }
+
+    if (strcmp(parts[index], "") == 0) {
+        return object_resolve_abs_path(parent, parts, index + 1);
+    }
+
+    prop = object_property_find(parent, parts[index]);
+    if (prop == NULL) {
+        return NULL;
+    }
+
+    child = NULL;
+    if (strstart(prop->type, "link<", NULL)) {
+        Object **pchild = prop->opaque;
+        if (*pchild) {
+            child = *pchild;
+        }
+    } else if (strstart(prop->type, "child<", NULL)) {
+        child = prop->opaque;
+    }
+
+    if (!child) {
+        return NULL;
+    }
+
+    return object_resolve_abs_path(child, parts, index + 1);
+}
+
+static Object *object_resolve_partial_path(Object *parent,
+                                              gchar **parts,
+                                              bool *ambiguous)
+{
+    Object *obj;
+    ObjectProperty *prop;
+
+    obj = object_resolve_abs_path(parent, parts, 0);
+
+    QTAILQ_FOREACH(prop, &parent->properties, node) {
+        Object *found;
+
+        if (!strstart(prop->type, "child<", NULL)) {
+            continue;
+        }
+
+        found = object_resolve_partial_path(prop->opaque, parts, ambiguous);
+        if (found) {
+            if (obj) {
+                if (ambiguous) {
+                    *ambiguous = true;
+                }
+                return NULL;
+            }
+            obj = found;
+        }
+
+        if (ambiguous && *ambiguous) {
+            return NULL;
+        }
+    }
+
+    return obj;
+}
+
+Object *object_resolve_path(const char *path, bool *ambiguous)
+{
+    bool partial_path = true;
+    Object *obj;
+    gchar **parts;
+
+    parts = g_strsplit(path, "/", 0);
+    if (parts == NULL || parts[0] == NULL) {
+        g_strfreev(parts);
+        return object_get_root();
+    }
+
+    if (strcmp(parts[0], "") == 0) {
+        partial_path = false;
+    }
+
+    if (partial_path) {
+        if (ambiguous) {
+            *ambiguous = false;
+        }
+        obj = object_resolve_partial_path(object_get_root(), parts, ambiguous);
+    } else {
+        obj = object_resolve_abs_path(object_get_root(), parts, 1);
+    }
+
+    g_strfreev(parts);
+
+    return obj;
+}
+
+typedef struct StringProperty
+{
+    char *(*get)(Object *, Error **);
+    void (*set)(Object *, const char *, Error **);
+} StringProperty;
+
+static void object_property_get_str(Object *obj, Visitor *v, void *opaque,
+                                    const char *name, Error **errp)
+{
+    StringProperty *prop = opaque;
+    char *value;
+
+    value = prop->get(obj, errp);
+    if (value) {
+        visit_type_str(v, &value, name, errp);
+        g_free(value);
+    }
+}
+
+static void object_property_set_str(Object *obj, Visitor *v, void *opaque,
+                                  const char *name, Error **errp)
+{
+    StringProperty *prop = opaque;
+    char *value;
+    Error *local_err = NULL;
+
+    visit_type_str(v, &value, name, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    prop->set(obj, value, errp);
+    g_free(value);
+}
+
+static void object_property_release_str(Object *obj, const char *name,
+                                      void *opaque)
+{
+    StringProperty *prop = opaque;
+    g_free(prop);
+}
+
+void object_property_add_str(Object *obj, const char *name,
+                           char *(*get)(Object *, Error **),
+                           void (*set)(Object *, const char *, Error **),
+                           Error **errp)
+{
+    StringProperty *prop = g_malloc0(sizeof(*prop));
+
+    prop->get = get;
+    prop->set = set;
+
+    object_property_add(obj, name, "string",
+                        get ? object_property_get_str : NULL,
+                        set ? object_property_set_str : NULL,
+                        object_property_release_str,
+                        prop, errp);
+}