2 files changed, 18 insertions, 47 deletions
diff --git a/python/qemu/machine/machine.py b/python/qemu/machine/machine.py
index ae945ca3c9..1c6532a3d6 100644
--- a/python/qemu/machine/machine.py
+++ b/python/qemu/machine/machine.py
@@ -213,48 +213,22 @@ class QEMUMachine:
     def send_fd_scm(self, fd: Optional[int] = None,
                     file_path: Optional[str] = None) -> int:
         """
-        Send an fd or file_path to socket_scm_helper.
+        Send an fd or file_path to the remote via SCM_RIGHTS.
 
-        Exactly one of fd and file_path must be given.
-        If it is file_path, the helper will open that file and pass its own fd.
+        Exactly one of fd and file_path must be given.  If it is
+        file_path, the file will be opened read-only and the new file
+        descriptor will be sent to the remote.
         """
-        # In iotest.py, the qmp should always use unix socket.
-        assert self._qmp.is_scm_available()
-        if self._socket_scm_helper is None:
-            raise QEMUMachineError("No path to socket_scm_helper set")
-        if not os.path.exists(self._socket_scm_helper):
-            raise QEMUMachineError("%s does not exist" %
-                                   self._socket_scm_helper)
-
-        # This did not exist before 3.4, but since then it is
-        # mandatory for our purpose
-        if hasattr(os, 'set_inheritable'):
-            os.set_inheritable(self._qmp.get_sock_fd(), True)
-            if fd is not None:
-                os.set_inheritable(fd, True)
-
-        fd_param = ["%s" % self._socket_scm_helper,
-                    "%d" % self._qmp.get_sock_fd()]
-
         if file_path is not None:
             assert fd is None
-            fd_param.append(file_path)
+            with open(file_path, "rb") as passfile:
+                fd = passfile.fileno()
+                self._qmp.send_fd_scm(fd)
         else:
             assert fd is not None
-            fd_param.append(str(fd))
-
-        proc = subprocess.run(
-            fd_param,
-            stdin=subprocess.DEVNULL,
-            stdout=subprocess.PIPE,
-            stderr=subprocess.STDOUT,
-            check=False,
-            close_fds=False,
-        )
-        if proc.stdout:
-            LOG.debug(proc.stdout)
+            self._qmp.send_fd_scm(fd)
 
-        return proc.returncode
+        return 0
 
     @staticmethod
     def _remove_if_exists(path: str) -> None:
diff --git a/python/qemu/qmp/__init__.py b/python/qemu/qmp/__init__.py
index c27594b66a..358c0971d0 100644
--- a/python/qemu/qmp/__init__.py
+++ b/python/qemu/qmp/__init__.py
@@ -21,6 +21,7 @@ import errno
 import json
 import logging
 import socket
+import struct
 from types import TracebackType
 from typing import (
     Any,
@@ -408,18 +409,14 @@ class QEMUMonitorProtocol:
             raise ValueError(msg)
         self.__sock.settimeout(timeout)
 
-    def get_sock_fd(self) -> int:
+    def send_fd_scm(self, fd: int) -> None:
         """
-        Get the socket file descriptor.
-
-        @return The file descriptor number.
-        """
-        return self.__sock.fileno()
-
-    def is_scm_available(self) -> bool:
+        Send a file descriptor to the remote via SCM_RIGHTS.
         """
-        Check if the socket allows for SCM_RIGHTS.
+        if self.__sock.family != socket.AF_UNIX:
+            raise RuntimeError("Can't use SCM_RIGHTS on non-AF_UNIX socket.")
 
-        @return True if SCM_RIGHTS is available, otherwise False.
-        """
-        return self.__sock.family == socket.AF_UNIX
+        self.__sock.sendmsg(
+            [b' '],
+            [(socket.SOL_SOCKET, socket.SCM_RIGHTS, struct.pack('@i', fd))]
+        )