diff --git a/hw/pci-bridge/ioh3420.c b/hw/pci-bridge/ioh3420.c
index 815bed4..0f7f209 100644
--- a/hw/pci-bridge/ioh3420.c
+++ b/hw/pci-bridge/ioh3420.c
@@ -92,9 +92,8 @@ static void ioh3420_reset(DeviceState *qdev)
 
 static int ioh3420_initfn(PCIDevice *d)
 {
-    PCIBridge *br = PCI_BRIDGE(d);
-    PCIEPort *p = DO_UPCAST(PCIEPort, br, br);
-    PCIESlot *s = DO_UPCAST(PCIESlot, port, p);
+    PCIEPort *p = PCIE_PORT(d);
+    PCIESlot *s = PCIE_SLOT(d);
     int rc;
 
     rc = pci_bridge_initfn(d, TYPE_PCIE_BUS);
@@ -148,9 +147,7 @@ err_bridge:
 
 static void ioh3420_exitfn(PCIDevice *d)
 {
-    PCIBridge *br = PCI_BRIDGE(d);
-    PCIEPort *p = DO_UPCAST(PCIEPort, br, br);
-    PCIESlot *s = DO_UPCAST(PCIESlot, port, p);
+    PCIESlot *s = PCIE_SLOT(d);
 
     pcie_aer_exit(d);
     pcie_chassis_del_slot(s);
@@ -180,7 +177,7 @@ PCIESlot *ioh3420_init(PCIBus *bus, int devfn, bool multifunction,
     qdev_prop_set_uint16(qdev, "slot", slot);
     qdev_init_nofail(qdev);
 
-    return DO_UPCAST(PCIESlot, port, DO_UPCAST(PCIEPort, br, br));
+    return PCIE_SLOT(d);
 }
 
 static const VMStateDescription vmstate_ioh3420 = {
@@ -190,23 +187,13 @@ static const VMStateDescription vmstate_ioh3420 = {
     .minimum_version_id_old = 1,
     .post_load = pcie_cap_slot_post_load,
     .fields = (VMStateField[]) {
-        VMSTATE_PCIE_DEVICE(port.br.parent_obj, PCIESlot),
-        VMSTATE_STRUCT(port.br.parent_obj.exp.aer_log, PCIESlot, 0,
-                       vmstate_pcie_aer_log, PCIEAERLog),
+        VMSTATE_PCIE_DEVICE(parent_obj.parent_obj.parent_obj, PCIESlot),
+        VMSTATE_STRUCT(parent_obj.parent_obj.parent_obj.exp.aer_log,
+                       PCIESlot, 0, vmstate_pcie_aer_log, PCIEAERLog),
         VMSTATE_END_OF_LIST()
     }
 };
 
-static Property ioh3420_properties[] = {
-    DEFINE_PROP_UINT8("port", PCIESlot, port.port, 0),
-    DEFINE_PROP_UINT8("chassis", PCIESlot, chassis, 0),
-    DEFINE_PROP_UINT16("slot", PCIESlot, slot, 0),
-    DEFINE_PROP_UINT16("aer_log_max", PCIESlot,
-                       port.br.parent_obj.exp.aer_log.log_max,
-                       PCIE_AER_LOG_MAX_DEFAULT),
-    DEFINE_PROP_END_OF_LIST(),
-};
-
 static void ioh3420_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -224,13 +211,11 @@ static void ioh3420_class_init(ObjectClass *klass, void *data)
     dc->desc = "Intel IOH device id 3420 PCIE Root Port";
     dc->reset = ioh3420_reset;
     dc->vmsd = &vmstate_ioh3420;
-    dc->props = ioh3420_properties;
 }
 
 static const TypeInfo ioh3420_info = {
     .name          = "ioh3420",
-    .parent        = TYPE_PCI_BRIDGE,
-    .instance_size = sizeof(PCIESlot),
+    .parent        = TYPE_PCIE_SLOT,
     .class_init    = ioh3420_class_init,
 };
 
diff --git a/hw/pci-bridge/xio3130_downstream.c b/hw/pci-bridge/xio3130_downstream.c
index 227a335..94f9781 100644
--- a/hw/pci-bridge/xio3130_downstream.c
+++ b/hw/pci-bridge/xio3130_downstream.c
@@ -56,9 +56,8 @@ static void xio3130_downstream_reset(DeviceState *qdev)
 
 static int xio3130_downstream_initfn(PCIDevice *d)
 {
-    PCIBridge *br = PCI_BRIDGE(d);
-    PCIEPort *p = DO_UPCAST(PCIEPort, br, br);
-    PCIESlot *s = DO_UPCAST(PCIESlot, port, p);
+    PCIEPort *p = PCIE_PORT(d);
+    PCIESlot *s = PCIE_SLOT(d);
     int rc;
 
     rc = pci_bridge_initfn(d, TYPE_PCIE_BUS);
@@ -113,9 +112,7 @@ err_bridge:
 
 static void xio3130_downstream_exitfn(PCIDevice *d)
 {
-    PCIBridge *br = PCI_BRIDGE(d);
-    PCIEPort *p = DO_UPCAST(PCIEPort, br, br);
-    PCIESlot *s = DO_UPCAST(PCIESlot, port, p);
+    PCIESlot *s = PCIE_SLOT(d);
 
     pcie_aer_exit(d);
     pcie_chassis_del_slot(s);
@@ -147,7 +144,7 @@ PCIESlot *xio3130_downstream_init(PCIBus *bus, int devfn, bool multifunction,
     qdev_prop_set_uint16(qdev, "slot", slot);
     qdev_init_nofail(qdev);
 
-    return DO_UPCAST(PCIESlot, port, DO_UPCAST(PCIEPort, br, br));
+    return PCIE_SLOT(d);
 }
 
 static const VMStateDescription vmstate_xio3130_downstream = {
@@ -157,23 +154,13 @@ static const VMStateDescription vmstate_xio3130_downstream = {
     .minimum_version_id_old = 1,
     .post_load = pcie_cap_slot_post_load,
     .fields = (VMStateField[]) {
-        VMSTATE_PCIE_DEVICE(port.br.parent_obj, PCIESlot),
-        VMSTATE_STRUCT(port.br.parent_obj.exp.aer_log, PCIESlot, 0,
-                       vmstate_pcie_aer_log, PCIEAERLog),
+        VMSTATE_PCIE_DEVICE(parent_obj.parent_obj.parent_obj, PCIESlot),
+        VMSTATE_STRUCT(parent_obj.parent_obj.parent_obj.exp.aer_log,
+                       PCIESlot, 0, vmstate_pcie_aer_log, PCIEAERLog),
         VMSTATE_END_OF_LIST()
     }
 };
 
-static Property xio3130_downstream_properties[] = {
-    DEFINE_PROP_UINT8("port", PCIESlot, port.port, 0),
-    DEFINE_PROP_UINT8("chassis", PCIESlot, chassis, 0),
-    DEFINE_PROP_UINT16("slot", PCIESlot, slot, 0),
-    DEFINE_PROP_UINT16("aer_log_max", PCIESlot,
-                       port.br.parent_obj.exp.aer_log.log_max,
-                       PCIE_AER_LOG_MAX_DEFAULT),
-    DEFINE_PROP_END_OF_LIST(),
-};
-
 static void xio3130_downstream_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -191,13 +178,11 @@ static void xio3130_downstream_class_init(ObjectClass *klass, void *data)
     dc->desc = "TI X3130 Downstream Port of PCI Express Switch";
     dc->reset = xio3130_downstream_reset;
     dc->vmsd = &vmstate_xio3130_downstream;
-    dc->props = xio3130_downstream_properties;
 }
 
 static const TypeInfo xio3130_downstream_info = {
     .name          = "xio3130-downstream",
-    .parent        = TYPE_PCI_BRIDGE,
-    .instance_size = sizeof(PCIESlot),
+    .parent        = TYPE_PCIE_SLOT,
     .class_init    = xio3130_downstream_class_init,
 };
 
diff --git a/hw/pci-bridge/xio3130_upstream.c b/hw/pci-bridge/xio3130_upstream.c
index b146253..59f97f6 100644
--- a/hw/pci-bridge/xio3130_upstream.c
+++ b/hw/pci-bridge/xio3130_upstream.c
@@ -53,8 +53,7 @@ static void xio3130_upstream_reset(DeviceState *qdev)
 
 static int xio3130_upstream_initfn(PCIDevice *d)
 {
-    PCIBridge *br = PCI_BRIDGE(d);
-    PCIEPort *p = DO_UPCAST(PCIEPort, br, br);
+    PCIEPort *p = PCIE_PORT(d);
     int rc;
 
     rc = pci_bridge_initfn(d, TYPE_PCIE_BUS);
@@ -125,7 +124,7 @@ PCIEPort *xio3130_upstream_init(PCIBus *bus, int devfn, bool multifunction,
     qdev_prop_set_uint8(qdev, "port", port);
     qdev_init_nofail(qdev);
 
-    return DO_UPCAST(PCIEPort, br, br);
+    return PCIE_PORT(d);
 }
 
 static const VMStateDescription vmstate_xio3130_upstream = {
@@ -134,21 +133,13 @@ static const VMStateDescription vmstate_xio3130_upstream = {
     .minimum_version_id = 1,
     .minimum_version_id_old = 1,
     .fields = (VMStateField[]) {
-        VMSTATE_PCIE_DEVICE(br.parent_obj, PCIEPort),
-        VMSTATE_STRUCT(br.parent_obj.exp.aer_log, PCIEPort, 0,
+        VMSTATE_PCIE_DEVICE(parent_obj.parent_obj, PCIEPort),
+        VMSTATE_STRUCT(parent_obj.parent_obj.exp.aer_log, PCIEPort, 0,
                        vmstate_pcie_aer_log, PCIEAERLog),
         VMSTATE_END_OF_LIST()
     }
 };
 
-static Property xio3130_upstream_properties[] = {
-    DEFINE_PROP_UINT8("port", PCIEPort, port, 0),
-    DEFINE_PROP_UINT16("aer_log_max", PCIEPort,
-                       br.parent_obj.exp.aer_log.log_max,
-                       PCIE_AER_LOG_MAX_DEFAULT),
-    DEFINE_PROP_END_OF_LIST(),
-};
-
 static void xio3130_upstream_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -166,13 +157,11 @@ static void xio3130_upstream_class_init(ObjectClass *klass, void *data)
     dc->desc = "TI X3130 Upstream Port of PCI Express Switch";
     dc->reset = xio3130_upstream_reset;
     dc->vmsd = &vmstate_xio3130_upstream;
-    dc->props = xio3130_upstream_properties;
 }
 
 static const TypeInfo xio3130_upstream_info = {
     .name          = "x3130-upstream",
-    .parent        = TYPE_PCI_BRIDGE,
-    .instance_size = sizeof(PCIEPort),
+    .parent        = TYPE_PCIE_PORT,
     .class_init    = xio3130_upstream_class_init,
 };
 
diff --git a/hw/pci/pcie_port.c b/hw/pci/pcie_port.c
index 91b53a0..2adb030 100644
--- a/hw/pci/pcie_port.c
+++ b/hw/pci/pcie_port.c
@@ -116,3 +116,55 @@ void pcie_chassis_del_slot(PCIESlot *s)
 {
     QLIST_REMOVE(s, next);
 }
+
+static Property pcie_port_props[] = {
+    DEFINE_PROP_UINT8("port", PCIEPort, port, 0),
+    DEFINE_PROP_UINT16("aer_log_max", PCIEPort,
+                       parent_obj.parent_obj.exp.aer_log.log_max,
+                       PCIE_AER_LOG_MAX_DEFAULT),
+    DEFINE_PROP_END_OF_LIST()
+};
+
+static void pcie_port_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+
+    dc->props = pcie_port_props;
+}
+
+static const TypeInfo pcie_port_type_info = {
+    .name = TYPE_PCIE_PORT,
+    .parent = TYPE_PCI_BRIDGE,
+    .instance_size = sizeof(PCIEPort),
+    .abstract = true,
+    .class_init = pcie_port_class_init,
+};
+
+static Property pcie_slot_props[] = {
+    DEFINE_PROP_UINT8("chassis", PCIESlot, chassis, 0),
+    DEFINE_PROP_UINT16("slot", PCIESlot, slot, 0),
+    DEFINE_PROP_END_OF_LIST()
+};
+
+static void pcie_slot_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+
+    dc->props = pcie_slot_props;
+}
+
+static const TypeInfo pcie_slot_type_info = {
+    .name = TYPE_PCIE_SLOT,
+    .parent = TYPE_PCIE_PORT,
+    .instance_size = sizeof(PCIESlot),
+    .abstract = true,
+    .class_init = pcie_slot_class_init,
+};
+
+static void pcie_port_register_types(void)
+{
+    type_register_static(&pcie_port_type_info);
+    type_register_static(&pcie_slot_type_info);
+}
+
+type_init(pcie_port_register_types)
diff --git a/include/hw/pci/pcie_port.h b/include/hw/pci/pcie_port.h
index d89aa61..e167bf7 100644
--- a/include/hw/pci/pcie_port.h
+++ b/include/hw/pci/pcie_port.h
@@ -24,8 +24,13 @@
 #include "hw/pci/pci_bridge.h"
 #include "hw/pci/pci_bus.h"
 
+#define TYPE_PCIE_PORT "pcie-port"
+#define PCIE_PORT(obj) OBJECT_CHECK(PCIEPort, (obj), TYPE_PCIE_PORT)
+
 struct PCIEPort {
-    PCIBridge   br;
+    /*< private >*/
+    PCIBridge   parent_obj;
+    /*< public >*/
 
     /* pci express switch port */
     uint8_t     port;
@@ -33,8 +38,13 @@ struct PCIEPort {
 
 void pcie_port_init_reg(PCIDevice *d);
 
+#define TYPE_PCIE_SLOT "pcie-slot"
+#define PCIE_SLOT(obj) OBJECT_CHECK(PCIESlot, (obj), TYPE_PCIE_SLOT)
+
 struct PCIESlot {
-    PCIEPort    port;
+    /*< private >*/
+    PCIEPort    parent_obj;
+    /*< public >*/
 
     /* pci express switch port with slot */
     uint8_t     chassis;
