[RFC PATCH v2 11/11] 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.
This is helpful especially for print-debugging.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
 tests/qemu-iotests/check      | 3 ++-
 tests/qemu-iotests/iotests.py | 9 +++++++++
 tests/qemu-iotests/testenv.py | 9 +++++++--
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index 6186495eee..6c469c14ff 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -33,6 +33,7 @@ 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='enable prints')
     p.add_argument('-gdb', action='store_true',
                    help="start gdbserver with $GDB_QEMU options. \
                          Default is localhost:12345")
@@ -116,7 +117,7 @@ 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)
 
     testfinder = TestFinder(test_dir=env.source_iotests)
 
diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index b23bfdfdff..bb29074b63 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -79,6 +79,8 @@
 if os.environ.get('GDB_QEMU'):
     qemu_gdb = ['gdbserver'] + os.environ.get('GDB_QEMU').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', '.')
@@ -618,6 +620,13 @@ def _post_shutdown(self) -> None:
         super()._post_shutdown()
         self.subprocess_check_valgrind(qemu_valgrind)
 
+    def _pre_launch(self) -> None:
+        super()._pre_launch()
+        if qemu_print and self._qemu_log_file != None:
+            # set QEMU binary output to stdout
+            self._qemu_log_file.close()
+            self._qemu_log_file = None
+
     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 86798bf752..9192d7154b 100644
--- a/tests/qemu-iotests/testenv.py
+++ b/tests/qemu-iotests/testenv.py
@@ -73,7 +73,7 @@ class TestEnv(ContextManager['TestEnv']):
                      'AIOMODE', 'CACHEMODE', 'VALGRIND_QEMU',
                      'CACHEMODE_IS_DEFAULT', 'IMGFMT_GENERIC', 'IMGOPTSSYNTAX',
                      'IMGKEYSECRET', 'QEMU_DEFAULT_MACHINE', 'MALLOC_PERTURB_',
-                     'GDB_QEMU']
+                     'GDB_QEMU', 'PRINT_QEMU']
 
     def get_env(self) -> Dict[str, str]:
         env = {}
@@ -165,7 +165,8 @@ 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
@@ -173,6 +174,9 @@ def __init__(self, imgfmt: str, imgproto: str, aiomode: str,
         self.misalign = misalign
         self.debug = debug
 
+        if qprint:
+            self.print_qemu = 'y'
+
         self.gdb_qemu = os.getenv('GDB_QEMU')
 
         if gdb and not self.gdb_qemu:
@@ -281,6 +285,7 @@ def print_env(self) -> None:
 SOCKET_SCM_HELPER -- {SOCKET_SCM_HELPER}
 GDB_QEMU      -- "{GDB_QEMU}"
 VALGRIND_QEMU     -- "{VALGRIND_QEMU}"
+PRINT_QEMU    --  "{PRINT_QEMU}"
 """
 
         args = collections.defaultdict(str, self.get_env())
-- 
2.30.2