Re: [Qemu-devel] [PATCH V2 2/3] qemu-iotests: add infrastructure of fd passing via SCM

[Luiz Capitulino <lcapitulino@redhat.com>]

On Tue, 27 Aug 2013 10:52:10 +0800
Wenchao Xia <xiawenc@linux.vnet.ibm.com> wrote:

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

I'm not familiar with the qemu-iotests and I can't tell if this
makes sense.

Kevin, Stefan, Markus, can you help reviewing this?

> 
> Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
> ---
>  QMP/qmp.py                    |    6 ++++++
>  tests/qemu-iotests/check      |    1 +
>  tests/qemu-iotests/iotests.py |   26 ++++++++++++++++++++++++++
>  3 files changed, 33 insertions(+), 0 deletions(-)
> 
> diff --git a/QMP/qmp.py b/QMP/qmp.py
> index c551df1..074f09a 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 74628ae..2f7f78e 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 33ad0ec..d40b2de 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 unused monitor
> +    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 +120,24 @@ class VM(object):
>          self._args.append(','.join(options))
>          return self
>  
> +    #Sendmsg must carry out some data to get qemu's notice, so send a blank
> +    #by default.
> +    def send_fd_scm(self, fd, msg=' '):
> +        #In iotest.py, the qmp should always use unix socket.
> +        assert self._qmp.is_scm_available()
> +        fd_bin = socket_scm_helper
> +        if os.path.exists(fd_bin) == False:
> +            print "Scm help program does not present, path %s." % fd_bin
> +            return -1
> +        fd_param = ["%s" % fd_bin,
> +                    "%d" % self._qmp.get_sock_fd(),
> +                    "%d" % fd,
> +                    "%s" % msg]
> +        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')