test_qos_sai: prevent cascading failures after fixture error

tests/qos/conftest.py

@@ -175,6 +175,49 @@ def skip_lossy_buffer_only(is_lossy_only_pool):
         pytest.skip("Skip test for lossy only pool")
 
 
+# Global variable to track fixture failures per parameter set for TestQosSai
+_fixture_failures = {}
+
+
+def pytest_sessionstart(session):
+    """Clear fixture failure tracking to prevent stale state in pytest-xdist workers."""
+    _fixture_failures.clear()
+
+
+def pytest_runtest_makereport(item, call):
+    """Record fixture failures during setup to skip subsequent tests in the same parameter set."""
+    if not (hasattr(item, 'cls') and item.cls and item.cls.__name__ == 'TestQosSai'):
+        return
+
+    if call.when == "setup" and call.excinfo is not None:
+        test_name = item.name
+        if '[' in test_name:
+            param_set = test_name.split('[')[1].rstrip(']')
+        else:
+            param_set = 'default'
+
+        _fixture_failures[param_set] = True
+
+
+def pytest_runtest_setup(item):
+    """Skip tests if fixtures failed for this parameter set."""
+    if not (hasattr(item, 'cls') and item.cls and item.cls.__name__ == 'TestQosSai'):
+        return
+
+    # Don't skip seed tests - let them fail naturally to show the root cause
+    if 'fixture_seed' in item.keywords:
+        return
+
+    test_name = item.name
+    if '[' in test_name:
+        param_set = test_name.split('[')[1].rstrip(']')
+    else:
+        param_set = 'default'
+
+    if param_set in _fixture_failures:
+        pytest.skip(f"Skipping because fixtures failed for parameter set [{param_set}]")
+
+
 @pytest.fixture(scope="module", autouse=True)
 def enable_dscp_remapping_on_dualtor_flag(request, duthost):
     """

tests/qos/test_qos_sai.py

@@ -413,6 +413,7 @@ def check_and_set_ecn_status(self, duthost, qosConfig, expected_status='on'):
 
         return ecn_status
 
+    @pytest.mark.fixture_seed
     def testParameter(
         self, duthosts, get_src_dst_asic_and_duts, dutConfig, dutQosConfig, ingressLosslessProfile,
         ingressLossyProfile, egressLosslessProfile, dualtor_ports_for_duts