When using valgrind on the test scripts, it generates a log file
in $TEST_DIR that is either print (if valgrind finds problems) or
otherwise deleted. Provide the same exact behavior when using
-valgrind on the python tests.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
 tests/qemu-iotests/iotests.py | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 56733954b2..b6166b6f7b 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -597,6 +597,26 @@ def __init__(self, path_suffix=''):
                          sock_dir=sock_dir)
         self._num_drives = 0
 
+    def subprocess_check_valgrind(self, valgrind) -> None:
+
+        if not valgrind:
+            return
+
+        valgrind_filename =  test_dir + "/" + str(self._popen.pid) + ".valgrind"
+
+        if self.exitcode() == 99:
+            with open(valgrind_filename) as f:
+                content = f.readlines()
+            for line in content:
+                print(line, end ="")
+            print("")
+        else:
+            os.remove(valgrind_filename)
+
+    def _post_shutdown(self) -> None:
+        super()._post_shutdown()
+        self.subprocess_check_valgrind(qemu_valgrind)
+
     def add_object(self, opts):
         self._args.append('-object')
         self._args.append(opts)
-- 
2.30.2