qemu-iotests: add infrastructure of fd passing via SCM

This patch make use of the compiled scm helper program to transfer
fd via unix socket at runtime.

Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

3 files changed, 30 insertions, 0 deletions

diff --git a/QMP/qmp.py b/QMP/qmp.py
index c551df1ed7..074f09a063 100644
--- a/QMP/qmp.py
+++ b/QMP/qmp.py
@@ -188,3 +188,9 @@ class QEMUMonitorProtocol:
 
     def settimeout(self, timeout):
         self.__sock.settimeout(timeout)
+
+    def get_sock_fd(self):
+        return self.__sock.fileno()
+
+    def is_scm_available(self):
+        return self.__sock.family == socket.AF_UNIX
diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index 4ecf497d8e..f5f328f5f5 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -164,6 +164,7 @@ QEMU_IO       -- $QEMU_IO
 IMGFMT        -- $FULL_IMGFMT_DETAILS
 IMGPROTO      -- $FULL_IMGPROTO_DETAILS
 PLATFORM      -- $FULL_HOST_DETAILS
+SOCKET_SCM_HELPER -- $SOCKET_SCM_HELPER
 
 EOF
 #MKFS_OPTIONS  -- $FULL_MKFS_OPTIONS
diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 33ad0ecb92..87b4a3a880 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -38,6 +38,8 @@ imgfmt = os.environ.get('IMGFMT', 'raw')
 imgproto = os.environ.get('IMGPROTO', 'file')
 test_dir = os.environ.get('TEST_DIR', '/var/tmp')
 
+socket_scm_helper = os.environ.get('SOCKET_SCM_HELPER', 'socket_scm_helper')
+
 def qemu_img(*args):
     '''Run qemu-img and return the exit code'''
     devnull = open('/dev/null', 'r+')
@@ -80,6 +82,12 @@ class VM(object):
                      '-display', 'none', '-vga', 'none']
         self._num_drives = 0
 
+    # This can be used to add an unused monitor instance.
+    def add_monitor_telnet(self, ip, port):
+        args = 'tcp:%s:%d,server,nowait,telnet' % (ip, port)
+        self._args.append('-monitor')
+        self._args.append(args)
+
     def add_drive(self, path, opts=''):
         '''Add a virtio-blk drive to the VM'''
         options = ['if=virtio',
@@ -112,6 +120,21 @@ class VM(object):
         self._args.append(','.join(options))
         return self
 
+    def send_fd_scm(self, fd_file_path):
+        # In iotest.py, the qmp should always use unix socket.
+        assert self._qmp.is_scm_available()
+        bin = socket_scm_helper
+        if os.path.exists(bin) == False:
+            print "Scm help program does not present, path '%s'." % bin
+            return -1
+        fd_param = ["%s" % bin,
+                    "%d" % self._qmp.get_sock_fd(),
+                    "%s" % fd_file_path]
+        devnull = open('/dev/null', 'rb')
+        p = subprocess.Popen(fd_param, stdin=devnull, stdout=sys.stdout,
+                             stderr=sys.stderr)
+        return p.wait()
+
     def launch(self):
         '''Launch the VM and establish a QMP connection'''
         devnull = open('/dev/null', 'rb')