From: Alexandr Moshkov <dtalexund...@yandex-team.ru>
Add new tests to check the correctness of the `-overcommit memlock`
option (possible values: off, on, on-fault) by using
`/proc/{qemu_pid}/status` file to check in VmSize, VmRSS and VmLck
values:
* if `memlock=off`, then VmLck = 0;
* if `memlock=on`, then VmLck > 0 and almost all memory is resident;
* if `memlock=on-fault`, then VmLck > 0 and only few memory is resident.
Signed-off-by: Alexandr Moshkov <dtalexund...@yandex-team.ru>
Message-ID: <20250525070737.54267-3-dtalexund...@yandex-team.ru>
[thuth: improved the text in a comment]
Signed-off-by: Thomas Huth <th...@redhat.com>
---
tests/functional/meson.build | 1 +
tests/functional/test_memlock.py | 79 ++++++++++++++++++++++++++++++++
2 files changed, 80 insertions(+)
create mode 100755 tests/functional/test_memlock.py
diff --git a/tests/functional/meson.build b/tests/functional/meson.build
index 52b4706cfe8..13079f58b66 100644
--- a/tests/functional/meson.build
+++ b/tests/functional/meson.build
@@ -68,6 +68,7 @@ tests_generic_system = [
'empty_cpu_model',
'info_usernet',
'version',
+ 'memlock',
]
tests_generic_linuxuser = [
diff --git a/tests/functional/test_memlock.py b/tests/functional/test_memlock.py
new file mode 100755
index 00000000000..8910cb6da33
--- /dev/null
+++ b/tests/functional/test_memlock.py
@@ -0,0 +1,79 @@
+#!/usr/bin/env python3
+#
+# Functional test that check overcommit memlock options
+#
+# Copyright (c) Yandex Technologies LLC, 2025
+#
+# Author:
+# Alexandr Moshkov <dtalexund...@yandex-team.ru>
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+import re
+
+from typing import Dict
+
+from qemu_test import QemuSystemTest
+from qemu_test import skipLockedMemoryTest
+
+
+STATUS_VALUE_PATTERN = re.compile(r'^(\w+):\s+(\d+) kB', re.MULTILINE)
+
+
+@skipLockedMemoryTest(2_097_152) # 2GB
+class MemlockTest(QemuSystemTest):
+ """
+ Runs a guest with memlock options.
+ Then verify, that this options is working correctly
+ by checking the smaps of the QEMU process.
+ """
+
+ def common_vm_setup_with_memlock(self, memlock):
+ self.vm.add_args('-overcommit', f'mem-lock={memlock}')
+ self.vm.launch()
+
+ def test_memlock_off(self):
+ self.common_vm_setup_with_memlock('off')
+
+ status = self.get_process_status_values(self.vm.get_pid())
+
+ self.assertTrue(status['VmLck'] == 0)
+
+ def test_memlock_on(self):
+ self.common_vm_setup_with_memlock('on')
+
+ status = self.get_process_status_values(self.vm.get_pid())
+
+ # VmLck > 0 kB and almost all memory is resident
+ self.assertTrue(status['VmLck'] > 0)
+ self.assertTrue(status['VmRSS'] >= status['VmSize'] * 0.70)
+
+ def test_memlock_onfault(self):
+ self.common_vm_setup_with_memlock('on-fault')
+
+ status = self.get_process_status_values(self.vm.get_pid())
+
+ # VmLck > 0 kB and only few memory is resident
+ self.assertTrue(status['VmLck'] > 0)
+ self.assertTrue(status['VmRSS'] <= status['VmSize'] * 0.30)
+
+ def get_process_status_values(self, pid: int) -> Dict[str, int]:
+ result = {}
+ raw_status = self._get_raw_process_status(pid)
+
+ for line in raw_status.split('\n'):
+ if m := STATUS_VALUE_PATTERN.match(line):
+ result[m.group(1)] = int(m.group(2))
+
+ return result
+
+ def _get_raw_process_status(self, pid: int) -> str:
+ try:
+ with open(f'/proc/{pid}/status', 'r') as f:
+ return f.read()
+ except FileNotFoundError:
+ self.skipTest("Can't open status file of the process")
+
+
+if __name__ == '__main__':
+ MemlockTest.main()
--
2.49.0
