diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
index b75ad06..c9cb6fa 100644
--- a/hw/ppc/pnv.c
+++ b/hw/ppc/pnv.c
@@ -571,10 +571,29 @@
 
 static void pnv_reset(MachineState *machine)
 {
+    PnvMachineState *pnv = PNV_MACHINE(machine);
+    IPMIBmc *bmc;
     void *fdt;
 
     qemu_devices_reset();
 
+    /*
+     * The machine should provide by default an internal BMC simulator.
+     * If not, try to use the BMC device that was provided on the command
+     * line.
+     */
+    bmc = pnv_bmc_find(&error_fatal);
+    if (!pnv->bmc) {
+        if (!bmc) {
+            warn_report("machine has no BMC device. Use '-device "
+                        "ipmi-bmc-sim,id=bmc0 -device isa-ipmi-bt,bmc=bmc0,irq=10' "
+                        "to define one");
+        } else {
+            pnv_bmc_set_pnor(bmc, pnv->pnor);
+            pnv->bmc = bmc;
+        }
+    }
+
     fdt = pnv_dt_create(machine);
 
     /* Pack resulting tree */
@@ -833,9 +852,6 @@
     }
     g_free(chip_typename);
 
-    /* Create the machine BMC simulator */
-    pnv->bmc = pnv_bmc_create(pnv->pnor);
-
     /* Instantiate ISA bus on chip 0 */
     pnv->isa_bus = pnv_isa_create(pnv->chips[0], &error_fatal);
 
@@ -845,8 +861,14 @@
     /* Create an RTC ISA device too */
     mc146818_rtc_init(pnv->isa_bus, 2000, NULL);
 
-    /* Create the IPMI BT device for communication with the BMC */
-    pnv_ipmi_bt_init(pnv->isa_bus, pnv->bmc, 10);
+    /*
+     * Create the machine BMC simulator and the IPMI BT device for
+     * communication with the BMC
+     */
+    if (defaults_enabled()) {
+        pnv->bmc = pnv_bmc_create(pnv->pnor);
+        pnv_ipmi_bt_init(pnv->isa_bus, pnv->bmc, 10);
+    }
 
     /*
      * OpenPOWER systems use a IPMI SEL Event message to notify the
diff --git a/hw/ppc/pnv_bmc.c b/hw/ppc/pnv_bmc.c
index 8863354..4e018b8 100644
--- a/hw/ppc/pnv_bmc.c
+++ b/hw/ppc/pnv_bmc.c
@@ -213,6 +213,18 @@
     .cmd_handlers = hiomap_cmds
 };
 
+
+void pnv_bmc_set_pnor(IPMIBmc *bmc, PnvPnor *pnor)
+{
+    object_ref(OBJECT(pnor));
+    object_property_add_const_link(OBJECT(bmc), "pnor", OBJECT(pnor),
+                                   &error_abort);
+
+    /* Install the HIOMAP protocol handlers to access the PNOR */
+    ipmi_sim_register_netfn(IPMI_BMC_SIMULATOR(bmc), IPMI_NETFN_OEM,
+                            &hiomap_netfn);
+}
+
 /*
  * Instantiate the machine BMC. PowerNV uses the QEMU internal
  * simulator but it could also be external.
@@ -232,3 +244,36 @@
 
     return IPMI_BMC(obj);
 }
+
+typedef struct ForeachArgs {
+    const char *name;
+    Object *obj;
+} ForeachArgs;
+
+static int bmc_find(Object *child, void *opaque)
+{
+    ForeachArgs *args = opaque;
+
+    if (object_dynamic_cast(child, args->name)) {
+        if (args->obj) {
+            return 1;
+        }
+        args->obj = child;
+    }
+    return 0;
+}
+
+IPMIBmc *pnv_bmc_find(Error **errp)
+{
+    ForeachArgs args = { TYPE_IPMI_BMC_SIMULATOR, NULL };
+    int ret;
+
+    ret = object_child_foreach_recursive(object_get_root(), bmc_find, &args);
+    if (ret) {
+        error_setg(errp, "machine should have only one BMC device. "
+                   "Use '-nodefaults'");
+        return NULL;
+    }
+
+    return args.obj ? IPMI_BMC(args.obj) : NULL;
+}
diff --git a/include/hw/ppc/pnv.h b/include/hw/ppc/pnv.h
index fb4d0c0..d4b0b0e 100644
--- a/include/hw/ppc/pnv.h
+++ b/include/hw/ppc/pnv.h
@@ -241,6 +241,8 @@
 void pnv_dt_bmc_sensors(IPMIBmc *bmc, void *fdt);
 void pnv_bmc_powerdown(IPMIBmc *bmc);
 IPMIBmc *pnv_bmc_create(PnvPnor *pnor);
+IPMIBmc *pnv_bmc_find(Error **errp);
+void pnv_bmc_set_pnor(IPMIBmc *bmc, PnvPnor *pnor);
 
 /*
  * POWER8 MMIO base addresses