[PATCH v3 01/14] Revert "python/aqmp: fix send_fd_scm for python 3.6.x"

["Daniel P. Berrangé" <berrange@redhat.com>]

This reverts commit a57cb3e23d5ac918a69d0aab918470ff0b429ff9.

The current code now only requires compatibility with Python
3.8 or later.

The conditional usage of 'sendmsg' on the async IO socket
wrapper will generate a deprecation warning on stderr
every time send_fd_scm is used with older Python versions.

This has the effect of breaking the QEMU I/O tests when run
on Python versions before the 'sendmsg' wrapper was removed.

Unconditionally accessing 'sock._sock' ensures we never use
the asyncio socket wrapper, and thus never risk triggering
deprecation warnings on any Python version

Most notably this fixes the QEMU block I/O tests on CentOS
Stream9 that use "sendmsg" for FD passing, which otherwise
generate deprecation messages breaking the expected output
comparison.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: John Snow <jsnow@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
---
 python/qemu/qmp/qmp_client.py | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/python/qemu/qmp/qmp_client.py b/python/qemu/qmp/qmp_client.py
index 8beccfe29d..7a115b693b 100644
--- a/python/qemu/qmp/qmp_client.py
+++ b/python/qemu/qmp/qmp_client.py
@@ -720,12 +720,9 @@ def send_fd_scm(self, fd: int) -> None:
         if sock.family != socket.AF_UNIX:
             raise QMPError("Sending file descriptors requires a UNIX socket.")
 
-        if not hasattr(sock, 'sendmsg'):
-            # We need to void the warranty sticker.
-            # Access to sendmsg is scheduled for removal in Python 3.11.
-            # Find the real backing socket to use it anyway.
-            sock = sock._sock  # pylint: disable=protected-access
-
+        # Void the warranty sticker.
+        # Access to sendmsg in asyncio is scheduled for removal in Python 3.11.
+        sock = sock._sock  # pylint: disable=protected-access
         sock.sendmsg(
             [b' '],
             [(socket.SOL_SOCKET, socket.SCM_RIGHTS, struct.pack('@i', fd))]
-- 
2.52.0