diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 17b514d1da..76a846ff9a 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -777,27 +777,11 @@ void pc_machine_done(Notifier *notifier, void *data)
     PCMachineState *pcms = container_of(notifier,
                                         PCMachineState, machine_done);
     X86MachineState *x86ms = X86_MACHINE(pcms);
-    PCIBus *bus = pcms->bus;
 
     /* set the number of CPUs */
     x86_rtc_set_cpus_count(x86ms->rtc, x86ms->boot_cpus);
 
-    if (bus) {
-        int extra_hosts = 0;
-
-        QLIST_FOREACH(bus, &bus->child, sibling) {
-            /* look for expander root buses */
-            if (pci_bus_is_root(bus)) {
-                extra_hosts++;
-            }
-        }
-        if (extra_hosts && x86ms->fw_cfg) {
-            uint64_t *val = g_malloc(sizeof(*val));
-            *val = cpu_to_le64(extra_hosts);
-            fw_cfg_add_file(x86ms->fw_cfg,
-                    "etc/extra-pci-roots", val, sizeof(*val));
-        }
-    }
+    fw_cfg_add_extra_pci_roots(pcms->bus, x86ms->fw_cfg);
 
     acpi_setup();
     if (x86ms->fw_cfg) {
diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
index 08539a1aab..282ba93e2e 100644
--- a/hw/nvram/fw_cfg.c
+++ b/hw/nvram/fw_cfg.c
@@ -40,6 +40,7 @@
 #include "qemu/cutils.h"
 #include "qapi/error.h"
 #include "hw/acpi/aml-build.h"
+#include "hw/pci/pci_bus.h"
 
 #define FW_CFG_FILE_SLOTS_DFLT 0x20
 
@@ -1061,6 +1062,28 @@ bool fw_cfg_add_from_generator(FWCfgState *s, const char *filename,
     return true;
 }
 
+void fw_cfg_add_extra_pci_roots(PCIBus *bus, FWCfgState *s)
+{
+    int extra_hosts = 0;
+
+    if (!bus) {
+        return;
+    }
+
+    QLIST_FOREACH(bus, &bus->child, sibling) {
+        /* look for expander root buses */
+        if (pci_bus_is_root(bus)) {
+            extra_hosts++;
+        }
+    }
+
+    if (extra_hosts && s) {
+        uint64_t *val = g_malloc(sizeof(*val));
+        *val = cpu_to_le64(extra_hosts);
+        fw_cfg_add_file(s, "etc/extra-pci-roots", val, sizeof(*val));
+    }
+}
+
 static void fw_cfg_machine_reset(void *opaque)
 {
     MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h
index 8a9f5738bf..0e7a8bc7af 100644
--- a/include/hw/nvram/fw_cfg.h
+++ b/include/hw/nvram/fw_cfg.h
@@ -308,6 +308,15 @@ void *fw_cfg_modify_file(FWCfgState *s, const char *filename, void *data,
 bool fw_cfg_add_from_generator(FWCfgState *s, const char *filename,
                                const char *gen_id, Error **errp);
 
+/**
+ * fw_cfg_add_extra_pci_roots:
+ * @bus: main pci root bus to be scanned from
+ * @s: fw_cfg device being modified
+ *
+ * Add a new fw_cfg item...
+ */
+void fw_cfg_add_extra_pci_roots(PCIBus *bus, FWCfgState *s);
+
 FWCfgState *fw_cfg_init_io_dma(uint32_t iobase, uint32_t dma_iobase,
                                 AddressSpace *dma_as);
 FWCfgState *fw_cfg_init_io(uint32_t iobase);