diff --git a/hw/pci-host/pnv_phb3.c b/hw/pci-host/pnv_phb3.c
index c78084cce7..3467bbb5d9 100644
--- a/hw/pci-host/pnv_phb3.c
+++ b/hw/pci-host/pnv_phb3.c
@@ -1142,8 +1142,24 @@ static const TypeInfo pnv_phb3_root_bus_info = {
 static void pnv_phb3_root_port_realize(DeviceState *dev, Error **errp)
 {
     PCIERootPortClass *rpc = PCIE_ROOT_PORT_GET_CLASS(dev);
+    PCIDevice *pci = PCI_DEVICE(dev);
+    PCIBus *bus = pci_get_bus(pci);
+    PnvPHB3 *phb = NULL;
     Error *local_err = NULL;
 
+    phb = (PnvPHB3 *) object_dynamic_cast(OBJECT(bus->qbus.parent),
+                                          TYPE_PNV_PHB3);
+
+    if (!phb) {
+        error_setg(errp,
+"pnv_phb3_root_port devices must be connected to pnv-phb3 buses");
+        return;
+    }
+
+    /* Set unique chassis/slot values for the root port */
+    qdev_prop_set_uint8(&pci->qdev, "chassis", phb->chip_id);
+    qdev_prop_set_uint16(&pci->qdev, "slot", phb->phb_id);
+
     rpc->parent_realize(dev, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);