[QoS] QoS rule check also considers the direction

The method ``check_bandwidth_rule_conflict`` now takes into account the
rules direction when checking the compatibility between bandwidth limit
and minimum bandwidth rules.

Closes-Bug: #2100853
Change-Id: I21244595f501e35919a97fd048b643f951b18500
(cherry picked from commit b658c52d83)

neutron/objects/qos/qos_policy_validator.py

@@ -25,10 +25,15 @@ def check_bandwidth_rule_conflict(policy, rule_data):
     doesn't conflict with the existing rules.
     Raises an exception if conflict is identified.
     """
+    direction = rule_data.get('direction')
     for rule in policy.rules:
         if rule.rule_type == qos_consts.RULE_TYPE_DSCP_MARKING:
             # Skip checks if Rule is DSCP
             continue
+        if direction and rule.direction != direction:
+            # Rule check must be done within the same direction.
+            # DSCP rules have no direction.
+            continue
         if rule.rule_type == qos_consts.RULE_TYPE_MINIMUM_BANDWIDTH:
             if "max_kbps" in rule_data and (
                     int(rule.min_kbps) > int(rule_data["max_kbps"])):

neutron/tests/unit/objects/qos/test_qos_policy_validator.py

@@ -0,0 +1,53 @@
+# Copyright (c) 2025 Red Hat Inc.
+# All rights reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+from neutron_lib import constants as lib_consts
+from neutron_lib import context
+from neutron_lib.exceptions import qos as qos_exc
+from neutron_lib.services.qos import constants as qos_consts
+
+from neutron.objects.qos import policy
+from neutron.objects.qos import qos_policy_validator
+from neutron.objects.qos import rule
+from neutron.tests.unit import testlib_api
+
+
+class TestCheckBandwidthRuleConflict(testlib_api.SqlTestCase):
+
+    def setUp(self):
+        super().setUp()
+        self.context = context.get_admin_context()
+        self.qos_policy = policy.QosPolicy(self.context)
+        self.qos_policy.create()
+        self.max_bw_egress = 10000
+        self.max_bw_rule = rule.QosBandwidthLimitRule(
+            self.context, qos_policy_id=self.qos_policy.id,
+            max_kbps=self.max_bw_egress,
+            direction=lib_consts.EGRESS_DIRECTION)
+        self.max_bw_rule.create()
+        self.qos_policy.rules = [self.max_bw_rule]
+
+    def test_check_bandwidth_rule_conflict_different_direction(self):
+        rule_data = {qos_consts.DIRECTION: lib_consts.INGRESS_DIRECTION,
+                     qos_consts.MIN_KBPS: self.max_bw_egress + 1}
+        qos_policy_validator.check_bandwidth_rule_conflict(
+            self.qos_policy, rule_data)
+
+    def test_check_bandwidth_rule_conflict_same_direction(self):
+        rule_data = {qos_consts.DIRECTION: lib_consts.EGRESS_DIRECTION,
+                     qos_consts.MIN_KBPS: self.max_bw_egress + 1}
+        self.assertRaises(qos_exc.QoSRuleParameterConflict,
+                          qos_policy_validator.check_bandwidth_rule_conflict,
+                          self.qos_policy, rule_data)