diff --git a/poky/scripts/runqemu b/poky/scripts/runqemu
index bd3aee0..c6b7580 100755
--- a/poky/scripts/runqemu
+++ b/poky/scripts/runqemu
@@ -218,7 +218,7 @@
         self.tcpserial_portnum = ''
         self.custombiosdir = ''
         self.lock = ''
-        self.lock_descriptor = ''
+        self.lock_descriptor = None
         self.bitbake_e = ''
         self.snapshot = False
         self.fstypes = ('ext2', 'ext3', 'ext4', 'jffs2', 'nfs', 'btrfs',
@@ -252,13 +252,17 @@
                 logger.info(msg)
             if self.lock_descriptor:
                 self.lock_descriptor.close()
+                self.lock_descriptor = None
             return False
         return True
 
     def release_lock(self):
-        fcntl.flock(self.lock_descriptor, fcntl.LOCK_UN)
-        self.lock_descriptor.close()
-        os.remove(self.lock)
+        if self.lock_descriptor:
+            logger.debug("Releasing lockfile for tap device '%s'" % self.tap)
+            fcntl.flock(self.lock_descriptor, fcntl.LOCK_UN)
+            self.lock_descriptor.close()
+            os.remove(self.lock)
+            self.lock_descriptor = None
 
     def get(self, key):
         if key in self.d:
@@ -1211,7 +1215,10 @@
         cmd = "%s %s" % (self.qemu_opt, kernel_opts)
         cmds = shlex.split(cmd)
         logger.info('Running %s\n' % cmd)
-        process = subprocess.Popen(cmds, stderr=subprocess.PIPE)
+        pass_fds = []
+        if self.lock_descriptor:
+            pass_fds = [self.lock_descriptor.fileno()]
+        process = subprocess.Popen(cmds, stderr=subprocess.PIPE, pass_fds=pass_fds)
         self.qemupid = process.pid
         retcode = process.wait()
         if retcode:
@@ -1232,9 +1239,7 @@
             cmd = 'sudo %s %s %s' % (self.qemuifdown, self.tap, self.bindir_native)
             logger.debug('Running %s' % cmd)
             subprocess.check_call(cmd, shell=True)
-        if self.lock_descriptor:
-            logger.info("Releasing lockfile for tap device '%s'" % self.tap)
-            self.release_lock()
+        self.release_lock()
 
         if self.nfs_running:
             logger.info("Shutting down the userspace NFS server...")
@@ -1313,7 +1318,7 @@
             logger.info("SIGTERM received")
             os.kill(config.qemupid, signal.SIGTERM)
             config.cleanup()
-            subprocess.run(["tput", "smam"])
+            subprocess.check_call(["tput", "smam"])
         signal.signal(signal.SIGTERM, sigterm_handler)
 
         config.check_args()
@@ -1335,7 +1340,7 @@
         return 1
     finally:
         config.cleanup()
-        subprocess.run(["tput", "smam"])
+        subprocess.check_call(["tput", "smam"])
 
 if __name__ == "__main__":
     sys.exit(main())