diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index aaa27ba7d2..4fa1a4ac76 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -10360,6 +10360,21 @@ qemuDomainDiskChangeSupported(virDomainDiskDefPtr disk,
     return true;
 }
 
+
+/* Return the format node name for a given disk of an online guest */
+const char *
+qemuDomainDiskNodeFormatLookup(virDomainObjPtr vm,
+                               const char *disk)
+{
+    size_t i;
+
+    for (i = 0; i < vm->def->ndisks; i++) {
+        if (STREQ(vm->def->disks[i]->dst, disk))
+            return vm->def->disks[i]->src->nodeformat;
+    }
+    return NULL;
+}
+
 bool
 qemuDomainDiskBlockJobIsActive(virDomainDiskDefPtr disk)
 {
diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index eeb07180b7..b76d3cace9 100644
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -804,6 +804,9 @@ int qemuDomainDetermineDiskChain(virQEMUDriverPtr driver,
 bool qemuDomainDiskChangeSupported(virDomainDiskDefPtr disk,
                                    virDomainDiskDefPtr orig_disk);
 
+const char *qemuDomainDiskNodeFormatLookup(virDomainObjPtr vm,
+                                           const char *disk);
+
 int qemuDomainStorageFileInit(virQEMUDriverPtr driver,
                               virDomainObjPtr vm,
                               virStorageSourcePtr src,