[PATCH v6 15/16] qemu-iotests: add option to show qemu binary logs on stdout

[Emanuele Giuseppe Esposito <eesposit@redhat.com>]

Using the flag -p, allow the qemu binary to print to stdout.

Also create the common function _close_qemu_log_file() to
avoid accessing machine.py private fields directly and have
duplicate code.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 python/qemu/machine/machine.py | 9 ++++++---
 tests/qemu-iotests/check       | 4 +++-
 tests/qemu-iotests/iotests.py  | 8 ++++++++
 tests/qemu-iotests/testenv.py  | 9 +++++++--
 4 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/python/qemu/machine/machine.py b/python/qemu/machine/machine.py
index fdf2fc0e9c..c9d344d955 100644
--- a/python/qemu/machine/machine.py
+++ b/python/qemu/machine/machine.py
@@ -338,6 +338,11 @@ def _post_launch(self) -> None:
         if self._qmp_connection:
             self._qmp.accept(self._qmp_timer)
 
+    def _close_qemu_log_file(self) -> None:
+        if self._qemu_log_file is not None:
+            self._qemu_log_file.close()
+            self._qemu_log_file = None
+
     def _post_shutdown(self) -> None:
         """
         Called to cleanup the VM instance after the process has exited.
@@ -350,9 +355,7 @@ def _post_shutdown(self) -> None:
             self._qmp.close()
             self._qmp_connection = None
 
-        if self._qemu_log_file is not None:
-            self._qemu_log_file.close()
-            self._qemu_log_file = None
+        self._close_qemu_log_file()
 
         self._load_io_log()
 
diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index ebd27946db..da1bfb839e 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -36,6 +36,8 @@ def make_argparser() -> argparse.ArgumentParser:
                    help='pretty print output for make check')
 
     p.add_argument('-d', dest='debug', action='store_true', help='debug')
+    p.add_argument('-p', dest='print', action='store_true',
+                help='redirects qemu\'s stdout and stderr to the test output')
     p.add_argument('-gdb', action='store_true',
                    help="start gdbserver with $GDB_OPTIONS options \
                         ('localhost:12345' if $GDB_OPTIONS is empty)")
@@ -119,7 +121,7 @@ if __name__ == '__main__':
                   aiomode=args.aiomode, cachemode=args.cachemode,
                   imgopts=args.imgopts, misalign=args.misalign,
                   debug=args.debug, valgrind=args.valgrind,
-                  gdb=args.gdb)
+                  gdb=args.gdb, qprint=args.print)
 
     if len(sys.argv) > 1 and sys.argv[-len(args.tests)-1] == '--':
         if not args.tests:
diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 7aa6707032..eee6fb7a9f 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -79,6 +79,8 @@
 if gdb_qemu_env:
     qemu_gdb = ['gdbserver'] + gdb_qemu_env.strip().split(' ')
 
+qemu_print = os.environ.get('PRINT_QEMU', False)
+
 imgfmt = os.environ.get('IMGFMT', 'raw')
 imgproto = os.environ.get('IMGPROTO', 'file')
 output_dir = os.environ.get('OUTPUT_DIR', '.')
@@ -613,6 +615,12 @@ def _post_shutdown(self) -> None:
         else:
             os.remove(valgrind_filename)
 
+    def _pre_launch(self) -> None:
+        super()._pre_launch()
+        if qemu_print:
+            # set QEMU binary output to stdout
+            self._close_qemu_log_file()
+
     def add_object(self, opts):
         self._args.append('-object')
         self._args.append(opts)
diff --git a/tests/qemu-iotests/testenv.py b/tests/qemu-iotests/testenv.py
index 8bf154376f..70da0d60c8 100644
--- a/tests/qemu-iotests/testenv.py
+++ b/tests/qemu-iotests/testenv.py
@@ -74,7 +74,7 @@ class TestEnv(ContextManager['TestEnv']):
                      'AIOMODE', 'CACHEMODE', 'VALGRIND_QEMU',
                      'CACHEMODE_IS_DEFAULT', 'IMGFMT_GENERIC', 'IMGOPTSSYNTAX',
                      'IMGKEYSECRET', 'QEMU_DEFAULT_MACHINE', 'MALLOC_PERTURB_',
-                     'GDB_OPTIONS']
+                     'GDB_OPTIONS', 'PRINT_QEMU']
 
     def prepare_subprocess(self, args: List[str]) -> Dict[str, str]:
         if self.debug:
@@ -181,7 +181,8 @@ def __init__(self, imgfmt: str, imgproto: str, aiomode: str,
                  misalign: bool = False,
                  debug: bool = False,
                  valgrind: bool = False,
-                 gdb: bool = False) -> None:
+                 gdb: bool = False,
+                 qprint: bool = False) -> None:
         self.imgfmt = imgfmt
         self.imgproto = imgproto
         self.aiomode = aiomode
@@ -189,6 +190,9 @@ def __init__(self, imgfmt: str, imgproto: str, aiomode: str,
         self.misalign = misalign
         self.debug = debug
 
+        if qprint:
+            self.print_qemu = 'y'
+
         if gdb:
             self.gdb_options = os.getenv('GDB_OPTIONS', DEF_GDB_OPTIONS)
             if not self.gdb_options:
@@ -299,6 +303,7 @@ def print_env(self) -> None:
 SOCKET_SCM_HELPER -- {SOCKET_SCM_HELPER}
 GDB_OPTIONS   -- {GDB_OPTIONS}
 VALGRIND_QEMU -- {VALGRIND_QEMU}
+PRINT_QEMU_OUTPUT -- {PRINT_QEMU}
 """
 
         args = collections.defaultdict(str, self.get_env())
-- 
2.31.1