tests: gdbstub: qemu: Cross-validate test behavior

Add a testcase to run the same test application and GDB script
which we use for Zephyr GDB stub testing, but now with
the GDB stub enabled at QEMU itself.

Signed-off-by: Dmitrii Golovanov <dmitrii.golovanov@intel.com>

tests/subsys/debug/gdbstub/prj.conf

@@ -1,5 +1,3 @@
-CONFIG_GDBSTUB=y
-CONFIG_GDBSTUB_SERIAL_BACKEND=y
 CONFIG_NO_OPTIMIZATIONS=y
 CONFIG_USERSPACE=y
 CONFIG_KOBJECT_TEXT_AREA=4096

tests/subsys/debug/gdbstub/pytest/test_gdbstub.py

@@ -59,7 +59,15 @@ def expected_gdb():
     re.compile(r'GDB:PASSED'),
     ]
 
-def test_gdbstub(dut: DeviceAdapter, gdb_process, expected_app, expected_gdb):
+@pytest.fixture(scope="module")
+def expected_gdb_detach():
+    return [
+    re.compile(r'Inferior.*will be killed'),  # Zephyr gdbstub
+    re.compile(r'Inferior.*detached')  # QEMU gdbstub
+    ]
+
+
+def test_gdbstub(dut: DeviceAdapter, gdb_process, expected_app, expected_gdb, expected_gdb_detach):
     """
     Test gdbstub feature using a GDB script. We connect to the DUT, run the
     GDB script then evaluate return code and expected patterns at the GDB
@@ -68,7 +76,7 @@ def test_gdbstub(dut: DeviceAdapter, gdb_process, expected_app, expected_gdb):
     logger.debug(f"GDB output:\n{gdb_process.stdout}\n")
     assert gdb_process.returncode == 0
     assert all([ex_re.search(gdb_process.stdout, re.MULTILINE) for ex_re in expected_gdb]), 'No expected GDB output'
-    assert 'Inferior 1 [Remote target] will be killed' in gdb_process.stdout,'Expecting explicit quit from the GDB script and kill QEMU test app.'
+    assert any([ex_re.search(gdb_process.stdout, re.MULTILINE) for ex_re in expected_gdb_detach]), 'No expected GDB quit'
     app_output = '\n'.join(dut.readlines(print_output = False))
     logger.debug(f"App output:\n{app_output}\n")
     assert all([ex_re.search(app_output, re.MULTILINE) for ex_re in expected_app]), 'No expected Application output'

tests/subsys/debug/gdbstub/testcase.yaml

@@ -5,7 +5,8 @@
 #
 
 tests:
-  debug.gdbstub.breakpoints:
+  # Connect to Zephyr gdbstub and run a simple GDB script
+  debug.gdbstub_zephyr.breakpoints:
     platform_allow: qemu_x86
     harness: pytest
     harness_config:
@@ -17,12 +18,40 @@ tests:
         - "--gdb_script"
         - "test_breakpoints.gdbinit"
         - "--gdb_target_remote"
-        - "tcp:127.0.0.1:5678"
+        - "tcp::5678"
     tags:
       - debug
       - gdbstub
       - pytest
     extra_configs:
       # Make sure the gdbstub port chosen is unique for this test to avoid conflicts
       # when Twister runs tests in parallel on the same host.
-      - CONFIG_QEMU_EXTRA_FLAGS="-serial tcp:127.0.0.1:5678,server"
+      - CONFIG_GDBSTUB=y
+      - CONFIG_GDBSTUB_SERIAL_BACKEND=y
+      - CONFIG_QEMU_EXTRA_FLAGS="-serial tcp::5678,server"
+
+  # Connect to QEMU gdbstub and run the same simple GDB script
+  # Use non-default QEMU gdbstub port 1235
+  debug.gdbstub_qemu.breakpoints:
+    platform_allow: qemu_x86
+    harness: pytest
+    harness_config:
+      pytest_root:
+        - "pytest/test_gdbstub.py"
+      pytest_args:
+        - "--gdb_timeout"
+        - "20"
+        - "--gdb_script"
+        - "test_breakpoints.gdbinit"
+        - "--gdb_target_remote"
+        - "tcp::1235"
+    tags:
+      - debug
+      - gdbstub
+      - pytest
+    extra_configs:
+      # Make sure the gdbstub port chosen is unique for this test to avoid conflicts
+      # when Twister runs tests in parallel on the same host.
+      - CONFIG_QEMU_EXTRA_FLAGS="-S -gdb tcp::1235"
+      # Clear QEMU default 'tcp::1234'
+      - CONFIG_QEMU_GDBSERVER_LISTEN_DEV=""