[port/buffer] introduce a sync mechanism to protect port PG/queue fro…

…m changes under PFC storm (sonic-net#1143)

* [port/buffer] introduce a sync mechanism to protect port PG/queue from
changes under PFC storm

Signed-off-by: Stepan Blyschak <stepanb@mellanox.com>

* [pfcactionhandler] fix pg lock bit is not set

Signed-off-by: Stepan Blyschak <stepanb@mellanox.com>

* [portsorch_ut] add PfcZeroBufferHandlerLocksPortPgAndQueue unit test

Signed-off-by: Stepan Blyschak <stepanb@mellanox.com>

* [pfcactionhandler] add method header

Signed-off-by: Stepan Blyschak <stepanb@mellanox.com>

* [port.h] fix typos

Signed-off-by: Stepan Blyschak <stepanb@mellanox.com>

* [pfcactionhandler] fix method name that set lock bits

Signed-off-by: Stepan Blyschak <stepanb@mellanox.com>

orchagent/bufferorch.cpp

@@ -562,6 +562,11 @@ task_process_status BufferOrch::processQueue(Consumer &consumer)
                 SWSS_LOG_ERROR("Invalid queue index specified:%zd", ind);
                 return task_process_status::task_invalid_entry;
             }
+            if (port.m_queue_lock[ind])
+            {
+                SWSS_LOG_WARN("Queue %zd on port %s is locked, will retry", ind, port_name.c_str());
+                return task_process_status::task_need_retry;
+            }
             queue_id = port.m_queue_ids[ind];
             SWSS_LOG_DEBUG("Applying buffer profile:0x%" PRIx64 " to queue index:%zd, queue sai_id:0x%" PRIx64, sai_buffer_profile, ind, queue_id);
             sai_status_t sai_status = sai_queue_api->set_queue_attribute(queue_id, &attr);
@@ -661,6 +666,11 @@ task_process_status BufferOrch::processPriorityGroup(Consumer &consumer)
                 SWSS_LOG_ERROR("Invalid pg index specified:%zd", ind);
                 return task_process_status::task_invalid_entry;
             }
+            if (port.m_priority_group_lock[ind])
+            {
+                SWSS_LOG_WARN("Priority group %zd on port %s is locked, will retry", ind, port_name.c_str());
+                return task_process_status::task_need_retry;
+            }
             pg_id = port.m_priority_group_ids[ind];
             SWSS_LOG_DEBUG("Applying buffer profile:0x%" PRIx64 " to port:%s pg index:%zd, pg sai_id:0x%" PRIx64, sai_buffer_profile, port_name.c_str(), ind, pg_id);
             sai_status_t sai_status = sai_buffer_api->set_ingress_priority_group_attribute(pg_id, &attr);

orchagent/pfcactionhandler.cpp

@@ -434,6 +434,15 @@ PfcWdZeroBufferHandler::PfcWdZeroBufferHandler(sai_object_id_t port,
 {
     SWSS_LOG_ENTER();
 
+    Port portInstance;
+    if (!gPortsOrch->getPort(port, portInstance))
+    {
+        SWSS_LOG_ERROR("Cannot get port by ID 0x%" PRIx64, port);
+        return;
+    }
+
+    setPriorityGroupAndQueueLockFlag(portInstance, true);
+
     sai_attribute_t attr;
     attr.id = SAI_QUEUE_ATTR_BUFFER_PROFILE_ID;
 
@@ -462,13 +471,6 @@ PfcWdZeroBufferHandler::PfcWdZeroBufferHandler(sai_object_id_t port,
     m_originalQueueBufferProfile = oldQueueProfileId;
 
     // Get PG
-    Port portInstance;
-    if (!gPortsOrch->getPort(port, portInstance))
-    {
-        SWSS_LOG_ERROR("Cannot get port by ID 0x%" PRIx64, port);
-        return;
-    }
-
     sai_object_id_t pg = portInstance.m_priority_group_ids[static_cast <size_t> (queueId)];
 
     attr.id = SAI_INGRESS_PRIORITY_GROUP_ATTR_BUFFER_PROFILE;
@@ -533,6 +535,22 @@ PfcWdZeroBufferHandler::~PfcWdZeroBufferHandler(void)
         SWSS_LOG_ERROR("Failed to set buffer profile ID on queue 0x%" PRIx64 ": %d", getQueue(), status);
         return;
     }
+
+    setPriorityGroupAndQueueLockFlag(portInstance, false);
+}
+
+void PfcWdZeroBufferHandler::setPriorityGroupAndQueueLockFlag(Port& port, bool isLocked) const
+{
+    // set lock bits on PG and queue
+    port.m_priority_group_lock[static_cast<size_t>(getQueueId())] = isLocked;
+    for (size_t i = 0; i < port.m_queue_ids.size(); ++i)
+    {
+        if (port.m_queue_ids[i] == getQueue())
+        {
+            port.m_queue_lock[i] = isLocked;
+        }
+    }
+    gPortsOrch->setPort(port.m_alias, port);
 }
 
 PfcWdZeroBufferHandler::ZeroBufferProfile::ZeroBufferProfile(void)

orchagent/pfcactionhandler.h

@@ -31,17 +31,17 @@ class PfcWdActionHandler
                 uint8_t queueId, shared_ptr<Table> countersTable);
         virtual ~PfcWdActionHandler(void);
 
-        inline sai_object_id_t getPort(void)
+        inline sai_object_id_t getPort(void) const
         {
             return m_port;
         }
 
-        inline sai_object_id_t getQueue(void)
+        inline sai_object_id_t getQueue(void) const
         {
             return m_queue;
         }
 
-        inline sai_object_id_t getQueueId(void)
+        inline uint8_t getQueueId(void) const
         {
             return m_queueId;
         }
@@ -123,6 +123,12 @@ class PfcWdZeroBufferHandler: public PfcWdLossyHandler
         virtual ~PfcWdZeroBufferHandler(void);
 
     private:
+        /*
+         * Sets lock bits on port's priority group and queue
+         * to protect them from beeing changed by other Orch's
+         */
+        void setPriorityGroupAndQueueLockFlag(Port& port, bool isLocked) const;
+
         // Singletone class for keeping shared data - zero buffer profiles
         class ZeroBufferProfile
         {

orchagent/port.h

@@ -96,6 +96,16 @@ class Port
     std::vector<sai_object_id_t> m_priority_group_ids;
     sai_port_priority_flow_control_mode_t m_pfc_asym = SAI_PORT_PRIORITY_FLOW_CONTROL_MODE_COMBINED;
     uint8_t m_pfc_bitmask = 0;
+    /*
+     * Following two bit vectors are used to lock
+     * the PG/queue from being changed in BufferOrch.
+     * The use case scenario is when PfcWdZeroBufferHandler
+     * sets zero buffer profile it should protect PG/queue
+     * from being overwritten in BufferOrch.
+     */
+    std::vector<bool> m_queue_lock;
+    std::vector<bool> m_priority_group_lock;
+
 };
 
 }

orchagent/portsorch.cpp

@@ -2608,6 +2608,7 @@ void PortsOrch::initializeQueues(Port &port)
     SWSS_LOG_INFO("Get %d queues for port %s", attr.value.u32, port.m_alias.c_str());
 
     port.m_queue_ids.resize(attr.value.u32);
+    port.m_queue_lock.resize(attr.value.u32);
 
     if (attr.value.u32 == 0)
     {
@@ -2643,6 +2644,7 @@ void PortsOrch::initializePriorityGroups(Port &port)
     SWSS_LOG_INFO("Get %d priority groups for port %s", attr.value.u32, port.m_alias.c_str());
 
     port.m_priority_group_ids.resize(attr.value.u32);
+    port.m_priority_group_lock.resize(attr.value.u32);
 
     if (attr.value.u32 == 0)
     {

tests/mock_tests/mock_orchagent_main.h

@@ -54,3 +54,4 @@ extern sai_tunnel_api_t *sai_tunnel_api;
 extern sai_next_hop_api_t *sai_next_hop_api;
 extern sai_hostif_api_t *sai_hostif_api;
 extern sai_buffer_api_t *sai_buffer_api;
+extern sai_queue_api_t *sai_queue_api;

tests/mock_tests/portsorch_ut.cpp

@@ -1,6 +1,7 @@
 #include "ut_helper.h"
 #include "mock_orchagent_main.h"
 #include "mock_table.h"
+#include "pfcactionhandler.h"
 
 #include <sstream>
 
@@ -14,12 +15,15 @@ namespace portsorch_test
         shared_ptr<swss::DBConnector> m_app_db;
         shared_ptr<swss::DBConnector> m_config_db;
         shared_ptr<swss::DBConnector> m_state_db;
+        shared_ptr<swss::DBConnector> m_counters_db;
 
         PortsOrchTest()
         {
             // FIXME: move out from constructor
             m_app_db = make_shared<swss::DBConnector>(
                 "APPL_DB", 0);
+            m_counters_db = make_shared<swss::DBConnector>(
+                "COUNTERS_DB", 0);
             m_config_db = make_shared<swss::DBConnector>(
                 "CONFIG_DB", 0);
             m_state_db = make_shared<swss::DBConnector>(
@@ -310,4 +314,122 @@ namespace portsorch_test
         gBufferOrch->dumpPendingTasks(ts);
         ASSERT_TRUE(ts.empty());
     }
+
+    TEST_F(PortsOrchTest, PfcZeroBufferHandlerLocksPortPgAndQueue)
+    {
+        Table portTable = Table(m_app_db.get(), APP_PORT_TABLE_NAME);
+        Table pgTable = Table(m_config_db.get(), CFG_BUFFER_PG_TABLE_NAME);
+        Table profileTable = Table(m_config_db.get(), CFG_BUFFER_PROFILE_TABLE_NAME);
+        Table poolTable = Table(m_config_db.get(), CFG_BUFFER_POOL_TABLE_NAME);
+
+        // Get SAI default ports to populate DB
+        auto ports = ut_helper::getInitialSaiPorts();
+
+        // Create dependencies ...
+
+        const int portsorch_base_pri = 40;
+
+        vector<table_name_with_pri_t> ports_tables = {
+            { APP_PORT_TABLE_NAME, portsorch_base_pri + 5 },
+            { APP_VLAN_TABLE_NAME, portsorch_base_pri + 2 },
+            { APP_VLAN_MEMBER_TABLE_NAME, portsorch_base_pri },
+            { APP_LAG_TABLE_NAME, portsorch_base_pri + 4 },
+            { APP_LAG_MEMBER_TABLE_NAME, portsorch_base_pri }
+        };
+
+        ASSERT_EQ(gPortsOrch, nullptr);
+        gPortsOrch = new PortsOrch(m_app_db.get(), ports_tables);
+        vector<string> buffer_tables = { CFG_BUFFER_POOL_TABLE_NAME,
+                                         CFG_BUFFER_PROFILE_TABLE_NAME,
+                                         CFG_BUFFER_QUEUE_TABLE_NAME,
+                                         CFG_BUFFER_PG_TABLE_NAME,
+                                         CFG_BUFFER_PORT_INGRESS_PROFILE_LIST_NAME,
+                                         CFG_BUFFER_PORT_EGRESS_PROFILE_LIST_NAME };
+
+        ASSERT_EQ(gBufferOrch, nullptr);
+        gBufferOrch = new BufferOrch(m_config_db.get(), buffer_tables);
+
+        // Populate port table with SAI ports
+        for (const auto &it : ports)
+        {
+            portTable.set(it.first, it.second);
+        }
+
+        // Set PortConfigDone, PortInitDone
+        portTable.set("PortConfigDone", { { "count", to_string(ports.size()) } });
+        portTable.set("PortInitDone", { { "lanes", "0" } });
+
+        // refill consumer
+        gPortsOrch->addExistingData(&portTable);
+
+        // Apply configuration :
+        //  create ports
+
+        static_cast<Orch *>(gPortsOrch)->doTask();
+
+        // Apply configuration
+        //          ports
+        static_cast<Orch *>(gPortsOrch)->doTask();
+
+        ASSERT_TRUE(gPortsOrch->allPortsReady());
+
+        // No more tasks
+        vector<string> ts;
+        gPortsOrch->dumpPendingTasks(ts);
+        ASSERT_TRUE(ts.empty());
+        ts.clear();
+
+        // Simulate storm drop handler started on Ethernet0 TC 3
+        Port port;
+        gPortsOrch->getPort("Ethernet0", port);
+
+        auto countersTable = make_shared<Table>(m_counters_db.get(), COUNTERS_TABLE); 
+        auto dropHandler = make_unique<PfcWdZeroBufferHandler>(port.m_port_id, port.m_queue_ids[3], 3, countersTable);
+
+        // Create test buffer pool
+        poolTable.set(
+            "test_pool",
+            {
+                { "type", "ingress" },
+                { "mode", "dynamic" },
+                { "size", "4200000" },
+            });
+
+        // Create test buffer profile
+        profileTable.set("test_profile", { { "pool", "[BUFFER_POOL|test_pool]" },
+                                           { "xon", "14832" },
+                                           { "xoff", "14832" },
+                                           { "size", "35000" },
+                                           { "dynamic_th", "0" } });
+
+        // Apply profile on PGs 3-4 all ports
+        for (const auto &it : ports)
+        {
+            std::ostringstream oss;
+            oss << it.first << "|3-4";
+            pgTable.set(oss.str(), { { "profile", "[BUFFER_PROFILE|test_profile]" } });
+        }
+        gBufferOrch->addExistingData(&pgTable);
+        gBufferOrch->addExistingData(&poolTable);
+        gBufferOrch->addExistingData(&profileTable);
+
+        // process pool, profile and PGs
+        static_cast<Orch *>(gBufferOrch)->doTask();
+
+        auto pgConsumer = static_cast<Consumer*>(gBufferOrch->getExecutor(CFG_BUFFER_PG_TABLE_NAME));
+        pgConsumer->dumpPendingTasks(ts);
+        ASSERT_FALSE(ts.empty()); // PG is skipped
+        ts.clear();
+
+        // release zero buffer drop handler
+        dropHandler.reset();
+
+        // process PGs
+        static_cast<Orch *>(gBufferOrch)->doTask();
+
+        pgConsumer = static_cast<Consumer*>(gBufferOrch->getExecutor(CFG_BUFFER_PG_TABLE_NAME));
+        pgConsumer->dumpPendingTasks(ts);
+        ASSERT_TRUE(ts.empty()); // PG should be proceesed now
+        ts.clear();
+    }
 }

tests/mock_tests/ut_saihelper.cpp

@@ -77,6 +77,7 @@ namespace ut_helper
         sai_api_query(SAI_API_ACL, (void **)&sai_acl_api);
         sai_api_query(SAI_API_HOSTIF, (void **)&sai_hostif_api);
         sai_api_query(SAI_API_BUFFER, (void **)&sai_buffer_api);
+        sai_api_query(SAI_API_QUEUE, (void **)&sai_queue_api);
 
         return SAI_STATUS_SUCCESS;
     }
@@ -99,6 +100,7 @@ namespace ut_helper
         sai_acl_api = nullptr;
         sai_hostif_api = nullptr;
         sai_buffer_api = nullptr;
+        sai_queue_api = nullptr;
     }
 
     map<string, vector<FieldValueTuple>> getInitialSaiPorts()