Bug #21996: Reserve first 3 slots for hardcoded devices
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -690,6 +690,9 @@ qemuDomainPCIAddressSetPtr qemuDomainPCI
     if (virDomainDeviceInfoIterate(def, qemuCollectPCIAddress, addrs) < 0)
         goto error;
 
+    /* first 3 slots are reserved for hardcoded devices */
+    addrs->nextslot = 3;
+
     return addrs;
 
 no_memory: