diff --git a/hw/i440fx.c b/hw/i440fx.c
index 720a25a..fdf040b 100644
--- a/hw/i440fx.c
+++ b/hw/i440fx.c
@@ -191,7 +191,7 @@ static const VMStateDescription vmstate_i440fx_pmc = {
 static int i440fx_realize(SysBusDevice *dev)
 {
     I440FXState *s = I440FX(dev);
-    PCIHostState *h = PCI_HOST(s);
+    PCIHostState *h = PCI_HOST_BRIDGE(s);
     int bios_size, isa_bios_size;
     char *filename;
     int ret;
@@ -401,7 +401,7 @@ static void i440fx_pmc_class_init(ObjectClass *klass, void *data)
     dc->vmsd = &vmstate_i440fx_pmc;
 }
 
-static TypeInfo i440fx_pmc_info = {
+static const TypeInfo i440fx_pmc_info = {
     .name          = TYPE_I440FX_PMC,
     .parent        = TYPE_PCI_DEVICE,
     .instance_size = sizeof(I440FXPMCState),
@@ -418,7 +418,7 @@ static void i440fx_class_init(ObjectClass *klass, void *data)
     dc->no_user = 1;
 }
 
-static TypeInfo i440fx_info = {
+static const TypeInfo i440fx_info = {
     .name          = TYPE_I440FX,
     .parent        = TYPE_PCI_HOST_BRIDGE,
     .instance_size = sizeof(I440FXState),
diff --git a/hw/pc.c b/hw/pc.c
index d9a0443..f095109 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -1217,7 +1217,7 @@ static PCIBus *i440fx_init(I440FXPMCState **pi440fx_state, int *piix3_devfn,
     PCIHostState *h;
 
     s = I440FX(object_new(TYPE_I440FX));
-    h = PCI_HOST(s);
+    h = PCI_HOST_BRIDGE(s);
 
     /* FIXME make a properties */
     h->address_space = address_space_mem;
diff --git a/hw/pci_host.c b/hw/pci_host.c
index 3950e94..4e10042 100644
--- a/hw/pci_host.c
+++ b/hw/pci_host.c
@@ -165,11 +165,25 @@ const MemoryRegionOps pci_host_data_be_ops = {
     .endianness = DEVICE_BIG_ENDIAN,
 };
 
+void pci_host_set_mmio(PCIHostState *s, MemoryRegion *value)
+{
+    object_property_set_link(OBJECT(s), OBJECT(value), "mmio", NULL);
+}
+
+static void pci_host_initfn(Object *obj)
+{
+    PCIHostState *s = PCI_HOST_BRIDGE(obj);
+
+    object_property_add_link(obj, "mmio", "memory-region",
+                            (Object **)&s->address_space, NULL);
+}
+
 static const TypeInfo pci_host_type_info = {
     .name = TYPE_PCI_HOST_BRIDGE,
     .parent = TYPE_SYS_BUS_DEVICE,
     .abstract = true,
     .instance_size = sizeof(PCIHostState),
+    .instance_init = pci_host_initfn,
 };
 
 static void pci_host_register_types(void)
diff --git a/hw/pci_host.h b/hw/pci_host.h
index 4b9c300..9f28728 100644
--- a/hw/pci_host.h
+++ b/hw/pci_host.h
@@ -54,6 +54,8 @@ uint32_t pci_host_config_read_common(PCIDevice *pci_dev, uint32_t addr,
 void pci_data_write(PCIBus *s, uint32_t addr, uint32_t val, int len);
 uint32_t pci_data_read(PCIBus *s, uint32_t addr, int len);
 
+void pci_host_set_mmio(PCIHostState *s, MemoryRegion *value);
+
 extern const MemoryRegionOps pci_host_conf_le_ops;
 extern const MemoryRegionOps pci_host_conf_be_ops;
 extern const MemoryRegionOps pci_host_data_le_ops;
diff --git a/hw/piix3.c b/hw/piix3.c
index eca6ec8..3b69b15 100644
--- a/hw/piix3.c
+++ b/hw/piix3.c
@@ -204,7 +204,7 @@ static void piix3_class_init(ObjectClass *klass, void *data)
     k->class_id     = PCI_CLASS_BRIDGE_ISA;
 }
 
-static TypeInfo piix3_info = {
+static const TypeInfo piix3_info = {
     .name          = TYPE_PIIX3,
     .parent        = TYPE_PCI_DEVICE,
     .instance_size = sizeof(PIIX3State),
@@ -219,7 +219,7 @@ static void piix3_xen_class_init(ObjectClass *klass, void *data)
     k->config_write = piix3_write_config_xen;
 };
 
-static TypeInfo piix3_xen_info = {
+static const TypeInfo piix3_xen_info = {
     .name          = "PIIX3-xen",
     .parent        = TYPE_PIIX3,
     .instance_size = sizeof(PIIX3State),