diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
index f9e68c3..c36e725 100644
--- a/hw/pci-host/piix.c
+++ b/hw/pci-host/piix.c
@@ -629,11 +629,20 @@ static const TypeInfo i440fx_info = {
     .class_init    = i440fx_class_init,
 };
 
+static const char *i440fx_pcihost_root_bus_path(PCIHostState *host_bridge,
+                                                PCIBus *rootbus)
+{
+    /* For backwards compat with old device paths */
+    return "0000";
+}
+
 static void i440fx_pcihost_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+    PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(klass);
 
+    hc->root_bus_path = i440fx_pcihost_root_bus_path;
     k->init = i440fx_pcihost_initfn;
     dc->fw_name = "pci";
     dc->no_user = 1;
diff --git a/hw/pci-host/q35.c b/hw/pci-host/q35.c
index 3a5cff9..13148ed 100644
--- a/hw/pci-host/q35.c
+++ b/hw/pci-host/q35.c
@@ -63,6 +63,13 @@ static int q35_host_init(SysBusDevice *dev)
     return 0;
 }
 
+static const char *q35_host_root_bus_path(PCIHostState *host_bridge,
+                                          PCIBus *rootbus)
+{
+    /* For backwards compat with old device paths */
+    return "0000";
+}
+
 static Property mch_props[] = {
     DEFINE_PROP_UINT64("MCFG", Q35PCIHost, host.base_addr,
                         MCH_HOST_BRIDGE_PCIEXBAR_DEFAULT),
@@ -73,7 +80,9 @@ static void q35_host_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
+    PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(klass);
 
+    hc->root_bus_path = q35_host_root_bus_path;
     k->init = q35_host_init;
     dc->props = mch_props;
     dc->fw_name = "pci";
diff --git a/hw/pci/pci-hotplug-old.c b/hw/pci/pci-hotplug-old.c
index 37e0720..e251810 100644
--- a/hw/pci/pci-hotplug-old.c
+++ b/hw/pci/pci-hotplug-old.c
@@ -275,8 +275,8 @@ void pci_device_hot_add(Monitor *mon, const QDict *qdict)
     }
 
     if (dev) {
-        monitor_printf(mon, "OK domain %d, bus %d, slot %d, function %d\n",
-                       pci_find_domain(dev),
+        monitor_printf(mon, "OK root bus %s, bus %d, slot %d, function %d\n",
+                       pci_root_bus_path(dev),
                        pci_bus_num(dev->bus), PCI_SLOT(dev->devfn),
                        PCI_FUNC(dev->devfn));
     } else
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 69a6995..350b872 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -25,6 +25,7 @@
 #include "hw/pci/pci.h"
 #include "hw/pci/pci_bridge.h"
 #include "hw/pci/pci_bus.h"
+#include "hw/pci/pci_host.h"
 #include "monitor/monitor.h"
 #include "net/net.h"
 #include "sysemu/sysemu.h"
@@ -270,19 +271,20 @@ PCIBus *pci_device_root_bus(const PCIDevice *d)
     return bus;
 }
 
-int pci_find_domain(const PCIDevice *dev)
+const char *pci_root_bus_path(PCIDevice *dev)
 {
-    const PCIBus *rootbus = pci_device_root_bus(dev);
-    struct PCIHostBus *host;
+    PCIBus *rootbus = pci_device_root_bus(dev);
+    PCIHostState *host_bridge = PCI_HOST_BRIDGE(rootbus->qbus.parent);
+    PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_GET_CLASS(host_bridge);
 
-    QLIST_FOREACH(host, &host_buses, next) {
-        if (host->bus == rootbus) {
-            return host->domain;
-        }
+    assert(!rootbus->parent_dev);
+    assert(host_bridge->bus == rootbus);
+
+    if (hc->root_bus_path) {
+        return (*hc->root_bus_path)(host_bridge, rootbus);
     }
 
-    abort();    /* should not be reached */
-    return -1;
+    return rootbus->qbus.name;
 }
 
 static void pci_bus_init(PCIBus *bus, DeviceState *parent,
@@ -2000,10 +2002,10 @@ int pci_add_capability(PCIDevice *pdev, uint8_t cap_id,
         for (i = offset; i < offset + size; i++) {
             overlapping_cap = pci_find_capability_at_offset(pdev, i);
             if (overlapping_cap) {
-                fprintf(stderr, "ERROR: %04x:%02x:%02x.%x "
+                fprintf(stderr, "ERROR: %s:%02x:%02x.%x "
                         "Attempt to add PCI capability %x at offset "
                         "%x overlaps existing capability %x at offset %x\n",
-                        pci_find_domain(pdev), pci_bus_num(pdev->bus),
+                        pci_root_bus_path(pdev), pci_bus_num(pdev->bus),
                         PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn),
                         cap_id, offset, overlapping_cap, i);
                 return -EINVAL;
@@ -2137,30 +2139,30 @@ static char *pcibus_get_dev_path(DeviceState *dev)
      * domain:Bus:Slot.Func for systems without nested PCI bridges.
      * Slot.Function list specifies the slot and function numbers for all
      * devices on the path from root to the specific device. */
-    char domain[] = "DDDD:00";
+    const char *root_bus_path;
+    int root_bus_len;
     char slot[] = ":SS.F";
-    int domain_len = sizeof domain - 1 /* For '\0' */;
     int slot_len = sizeof slot - 1 /* For '\0' */;
     int path_len;
     char *path, *p;
     int s;
 
+    root_bus_path = pci_root_bus_path(d);
+    root_bus_len = strlen(root_bus_path);
+
     /* Calculate # of slots on path between device and root. */;
     slot_depth = 0;
     for (t = d; t; t = t->bus->parent_dev) {
         ++slot_depth;
     }
 
-    path_len = domain_len + slot_len * slot_depth;
+    path_len = root_bus_len + slot_len * slot_depth;
 
     /* Allocate memory, fill in the terminating null byte. */
     path = g_malloc(path_len + 1 /* For '\0' */);
     path[path_len] = '\0';
 
-    /* First field is the domain. */
-    s = snprintf(domain, sizeof domain, "%04x:00", pci_find_domain(d));
-    assert(s == domain_len);
-    memcpy(path, domain, domain_len);
+    memcpy(path, root_bus_path, root_bus_len);
 
     /* Fill in slot numbers. We walk up from device to root, so need to print
      * them in the reverse order, last to first. */
diff --git a/hw/pci/pci_host.c b/hw/pci/pci_host.c
index 12254b1..7dd9b25 100644
--- a/hw/pci/pci_host.c
+++ b/hw/pci/pci_host.c
@@ -169,6 +169,7 @@ static const TypeInfo pci_host_type_info = {
     .name = TYPE_PCI_HOST_BRIDGE,
     .parent = TYPE_SYS_BUS_DEVICE,
     .abstract = true,
+    .class_size = sizeof(PCIHostBridgeClass),
     .instance_size = sizeof(PCIHostState),
 };
 
diff --git a/hw/pci/pcie_aer.c b/hw/pci/pcie_aer.c
index 06f77ac..ca762ab 100644
--- a/hw/pci/pcie_aer.c
+++ b/hw/pci/pcie_aer.c
@@ -817,9 +817,9 @@ void pcie_aer_inject_error_print(Monitor *mon, const QObject *data)
     qdict = qobject_to_qdict(data);
 
     devfn = (int)qdict_get_int(qdict, "devfn");
-    monitor_printf(mon, "OK id: %s domain: %x, bus: %x devfn: %x.%x\n",
+    monitor_printf(mon, "OK id: %s root bus: %s, bus: %x devfn: %x.%x\n",
                    qdict_get_str(qdict, "id"),
-                   (int) qdict_get_int(qdict, "domain"),
+                   qdict_get_str(qdict, "root_bus"),
                    (int) qdict_get_int(qdict, "bus"),
                    PCI_SLOT(devfn), PCI_FUNC(devfn));
 }
@@ -1020,9 +1020,9 @@ int do_pcie_aer_inject_error(Monitor *mon,
 
     ret = pcie_aer_inject_error(dev, &err);
     *ret_data = qobject_from_jsonf("{'id': %s, "
-                                   "'domain': %d, 'bus': %d, 'devfn': %d, "
+                                   "'root_bus': %s, 'bus': %d, 'devfn': %d, "
                                    "'ret': %d}",
-                                   id, pci_find_domain(dev),
+                                   id, pci_root_bus_path(dev),
                                    pci_bus_num(dev->bus), dev->devfn,
                                    ret);
     assert(*ret_data);
diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index c8c12c8..f7be24c 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -696,11 +696,21 @@ static Property spapr_phb_properties[] = {
     DEFINE_PROP_END_OF_LIST(),
 };
 
+static const char *spapr_phb_root_bus_path(PCIHostState *host_bridge,
+                                           PCIBus *rootbus)
+{
+    sPAPRPHBState *sphb = SPAPR_PCI_HOST_BRIDGE(host_bridge);
+
+    return sphb->dtbusname;
+}
+
 static void spapr_phb_class_init(ObjectClass *klass, void *data)
 {
+    PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(klass);
     SysBusDeviceClass *sdc = SYS_BUS_DEVICE_CLASS(klass);
     DeviceClass *dc = DEVICE_CLASS(klass);
 
+    hc->root_bus_path = spapr_phb_root_bus_path;
     sdc->init = spapr_phb_init;
     dc->props = spapr_phb_properties;
     dc->reset = spapr_phb_reset;
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index f2bf1ed..e0597b7 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -391,7 +391,7 @@ void pci_for_each_device(PCIBus *bus, int bus_num,
                          void *opaque);
 PCIBus *pci_find_primary_bus(void);
 PCIBus *pci_device_root_bus(const PCIDevice *d);
-int pci_find_domain(const PCIDevice *dev);
+const char *pci_root_bus_path(PCIDevice *dev);
 PCIDevice *pci_find_device(PCIBus *bus, int bus_num, uint8_t devfn);
 int pci_qdev_find_device(const char *id, PCIDevice **pdev);
 PCIBus *pci_get_bus_devfn(int *devfnp, const char *devaddr);
diff --git a/include/hw/pci/pci_host.h b/include/hw/pci/pci_host.h
index 236cd0f..44052f2 100644
--- a/include/hw/pci/pci_host.h
+++ b/include/hw/pci/pci_host.h
@@ -33,6 +33,10 @@
 #define TYPE_PCI_HOST_BRIDGE "pci-host-bridge"
 #define PCI_HOST_BRIDGE(obj) \
     OBJECT_CHECK(PCIHostState, (obj), TYPE_PCI_HOST_BRIDGE)
+#define PCI_HOST_BRIDGE_CLASS(klass) \
+     OBJECT_CLASS_CHECK(PCIHostBridgeClass, (klass), TYPE_PCI_HOST_BRIDGE)
+#define PCI_HOST_BRIDGE_GET_CLASS(obj) \
+     OBJECT_GET_CLASS(PCIHostBridgeClass, (obj), TYPE_PCI_HOST_BRIDGE)
 
 struct PCIHostState {
     SysBusDevice busdev;
@@ -44,6 +48,12 @@ struct PCIHostState {
     PCIBus *bus;
 };
 
+typedef struct PCIHostBridgeClass {
+    SysBusDeviceClass parent_class;
+
+    const char *(*root_bus_path)(PCIHostState *, PCIBus *);
+} PCIHostBridgeClass;
+
 /* common internal helpers for PCI/PCIe hosts, cut off overflows */
 void pci_host_config_write_common(PCIDevice *pci_dev, uint32_t addr,
                                   uint32_t limit, uint32_t val, uint32_t len);
