diff --git a/hw/pci-host/uninorth.c b/hw/pci-host/uninorth.c
index fc59698f06..426b3c4e33 100644
--- a/hw/pci-host/uninorth.c
+++ b/hw/pci-host/uninorth.c
@@ -109,6 +109,27 @@ static const MemoryRegionOps unin_data_ops = {
     .endianness = DEVICE_LITTLE_ENDIAN,
 };
 
+static void pci_unin_main_realize(DeviceState *dev, Error **errp)
+{
+    UNINState *s = UNI_NORTH_PCI_HOST_BRIDGE(dev);
+    PCIHostState *h = PCI_HOST_BRIDGE(dev);
+
+    h->bus = pci_register_root_bus(dev, NULL,
+                                   pci_unin_set_irq, pci_unin_map_irq,
+                                   s->pic_irqs,
+                                   &s->pci_mmio,
+                                   get_system_io(),
+                                   PCI_DEVFN(11, 0), 4, TYPE_PCI_BUS);
+
+    pci_create_simple(h->bus, PCI_DEVFN(11, 0), "uni-north-agp");
+
+    /* DEC 21154 bridge */
+#if 0
+    /* XXX: not activated as PPC BIOS doesn't handle multiple buses properly */
+    pci_create_simple(h->bus, PCI_DEVFN(12, 0), "dec-21154");
+#endif
+}
+
 static void pci_unin_main_init(Object *obj)
 {
     UNINState *s = UNI_NORTH_PCI_HOST_BRIDGE(obj);
@@ -129,6 +150,21 @@ static void pci_unin_main_init(Object *obj)
     sysbus_init_mmio(sbd, &h->data_mem);
 }
 
+static void pci_u3_agp_realize(DeviceState *dev, Error **errp)
+{
+    UNINState *s = U3_AGP_HOST_BRIDGE(dev);
+    PCIHostState *h = PCI_HOST_BRIDGE(dev);
+
+    h->bus = pci_register_root_bus(dev, NULL,
+                                   pci_unin_set_irq, pci_unin_map_irq,
+                                   s->pic_irqs,
+                                   &s->pci_mmio,
+                                   get_system_io(),
+                                   PCI_DEVFN(11, 0), 4, TYPE_PCI_BUS);
+
+    pci_create_simple(h->bus, PCI_DEVFN(11, 0), "u3-agp");
+}
+
 static void pci_u3_agp_init(Object *obj)
 {
     UNINState *s = U3_AGP_HOST_BRIDGE(obj);
@@ -148,6 +184,19 @@ static void pci_u3_agp_init(Object *obj)
     sysbus_init_mmio(sbd, &h->data_mem);
 }
 
+static void pci_unin_agp_realize(DeviceState *dev, Error **errp)
+{
+    UNINState *s = UNI_NORTH_AGP_HOST_BRIDGE(dev);
+    PCIHostState *h = PCI_HOST_BRIDGE(dev);
+
+    h->bus = pci_register_root_bus(dev, NULL,
+                                   pci_unin_set_irq, pci_unin_map_irq,
+                                   s->pic_irqs,
+                                   &s->pci_mmio,
+                                   get_system_io(),
+                                   PCI_DEVFN(11, 0), 4, TYPE_PCI_BUS);
+}
+
 static void pci_unin_agp_init(Object *obj)
 {
     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
@@ -177,49 +226,14 @@ static void pci_unin_internal_init(Object *obj)
 }
 
 UNINState *pci_pmac_init(qemu_irq *pic,
-                         MemoryRegion *address_space_mem,
-                         MemoryRegion *address_space_io)
+                         MemoryRegion *address_space_mem)
 {
     DeviceState *dev;
     SysBusDevice *s;
-    PCIHostState *h;
     UNINState *d;
 
     /* Use values found on a real PowerMac */
-    /* Uninorth main bus */
-    dev = qdev_create(NULL, TYPE_UNI_NORTH_PCI_HOST_BRIDGE);
-    qdev_prop_set_ptr(dev, "pic-irqs", pic);
-    qdev_init_nofail(dev);
-    s = SYS_BUS_DEVICE(dev);
-    h = PCI_HOST_BRIDGE(s);
-    d = UNI_NORTH_PCI_HOST_BRIDGE(dev);
-    memory_region_init_alias(&d->pci_hole, OBJECT(d), "pci-hole", &d->pci_mmio,
-                             0x80000000ULL, 0x10000000ULL);
-    memory_region_add_subregion(address_space_mem, 0x80000000ULL,
-                                &d->pci_hole);
-
-    h->bus = pci_register_root_bus(dev, NULL,
-                                   pci_unin_set_irq, pci_unin_map_irq,
-                                   d->pic_irqs,
-                                   &d->pci_mmio,
-                                   address_space_io,
-                                   PCI_DEVFN(11, 0), 4, TYPE_PCI_BUS);
-
-#if 0
-    pci_create_simple(h->bus, PCI_DEVFN(11, 0), "uni-north");
-#endif
-
-    sysbus_mmio_map(s, 0, 0xf2800000);
-    sysbus_mmio_map(s, 1, 0xf2c00000);
-
-    /* DEC 21154 bridge */
-#if 0
-    /* XXX: not activated as PPC BIOS doesn't handle multiple buses properly */
-    pci_create_simple(h->bus, PCI_DEVFN(12, 0), "dec-21154");
-#endif
-
     /* Uninorth AGP bus */
-    pci_create_simple(h->bus, PCI_DEVFN(11, 0), "uni-north-agp");
     dev = qdev_create(NULL, TYPE_UNI_NORTH_AGP_HOST_BRIDGE);
     qdev_prop_set_ptr(dev, "pic-irqs", pic);
     qdev_init_nofail(dev);
@@ -239,16 +253,28 @@ UNINState *pci_pmac_init(qemu_irq *pic,
     sysbus_mmio_map(s, 1, 0xf4c00000);
 #endif
 
+    /* Uninorth main bus */
+    dev = qdev_create(NULL, TYPE_UNI_NORTH_PCI_HOST_BRIDGE);
+    qdev_prop_set_ptr(dev, "pic-irqs", pic);
+    qdev_init_nofail(dev);
+    s = SYS_BUS_DEVICE(dev);
+    d = UNI_NORTH_PCI_HOST_BRIDGE(dev);
+    memory_region_init_alias(&d->pci_hole, OBJECT(d), "pci-hole", &d->pci_mmio,
+                             0x80000000ULL, 0x10000000ULL);
+    memory_region_add_subregion(address_space_mem, 0x80000000ULL,
+                                &d->pci_hole);
+
+    sysbus_mmio_map(s, 0, 0xf2800000);
+    sysbus_mmio_map(s, 1, 0xf2c00000);
+
     return d;
 }
 
 UNINState *pci_pmac_u3_init(qemu_irq *pic,
-                            MemoryRegion *address_space_mem,
-                            MemoryRegion *address_space_io)
+                            MemoryRegion *address_space_mem)
 {
     DeviceState *dev;
     SysBusDevice *s;
-    PCIHostState *h;
     UNINState *d;
 
     /* Uninorth AGP bus */
@@ -256,7 +282,6 @@ UNINState *pci_pmac_u3_init(qemu_irq *pic,
     qdev_prop_set_ptr(dev, "pic-irqs", pic);
     qdev_init_nofail(dev);
     s = SYS_BUS_DEVICE(dev);
-    h = PCI_HOST_BRIDGE(dev);
     d = U3_AGP_HOST_BRIDGE(dev);
 
     memory_region_init_alias(&d->pci_hole, OBJECT(d), "pci-hole", &d->pci_mmio,
@@ -264,18 +289,9 @@ UNINState *pci_pmac_u3_init(qemu_irq *pic,
     memory_region_add_subregion(address_space_mem, 0x80000000ULL,
                                 &d->pci_hole);
 
-    h->bus = pci_register_root_bus(dev, NULL,
-                                   pci_unin_set_irq, pci_unin_map_irq,
-                                   d->pic_irqs,
-                                   &d->pci_mmio,
-                                   address_space_io,
-                                   PCI_DEVFN(11, 0), 4, TYPE_PCI_BUS);
-
     sysbus_mmio_map(s, 0, 0xf0800000);
     sysbus_mmio_map(s, 1, 0xf0c00000);
 
-    pci_create_simple(h->bus, 11 << 3, "u3-agp");
-
     return d;
 }
 
@@ -448,6 +464,7 @@ static void pci_unin_main_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
 
+    dc->realize = pci_unin_main_realize;
     dc->props = pci_unin_main_properties;
     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
 }
@@ -469,6 +486,7 @@ static void pci_u3_agp_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
 
+    dc->realize = pci_u3_agp_realize;
     dc->props = pci_u3_agp_properties;
     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
 }
@@ -490,6 +508,7 @@ static void pci_unin_agp_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
 
+    dc->realize = pci_unin_agp_realize;
     dc->props = pci_unin_agp_class_properties;
     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
 }
diff --git a/hw/ppc/mac.h b/hw/ppc/mac.h
index fcf13cb757..628415b255 100644
--- a/hw/ppc/mac.h
+++ b/hw/ppc/mac.h
@@ -89,11 +89,9 @@ PCIBus *pci_grackle_init(uint32_t base, qemu_irq *pic,
 
 /* UniNorth PCI */
 UNINState *pci_pmac_init(qemu_irq *pic,
-                         MemoryRegion *address_space_mem,
-                         MemoryRegion *address_space_io);
+                         MemoryRegion *address_space_mem);
 UNINState *pci_pmac_u3_init(qemu_irq *pic,
-                            MemoryRegion *address_space_mem,
-                            MemoryRegion *address_space_io);
+                            MemoryRegion *address_space_mem);
 
 /* Mac NVRAM */
 #define TYPE_MACIO_NVRAM "macio-nvram"
diff --git a/hw/ppc/mac_newworld.c b/hw/ppc/mac_newworld.c
index 34908d0dd7..f2b07207d3 100644
--- a/hw/ppc/mac_newworld.c
+++ b/hw/ppc/mac_newworld.c
@@ -346,12 +346,10 @@ static void ppc_core99_init(MachineState *machine)
 
     if (PPC_INPUT(env) == PPC_FLAGS_INPUT_970) {
         /* 970 gets a U3 bus */
-        uninorth_pci = pci_pmac_u3_init(pic, get_system_memory(),
-                                        get_system_io());
+        uninorth_pci = pci_pmac_u3_init(pic, get_system_memory());
         machine_arch = ARCH_MAC99_U3;
     } else {
-        uninorth_pci = pci_pmac_init(pic, get_system_memory(),
-                                     get_system_io());
+        uninorth_pci = pci_pmac_init(pic, get_system_memory());
         machine_arch = ARCH_MAC99;
     }
 
