Add a test for looping PFC frames to CPU

Summary: Add a test for sending a PFC frame and looping it back to the CPU. The test expects the PFC frame is unmodified. Reviewed By: nivinl Differential Revision: D62415045 fbshipit-source-id: 4a75850018ccc82e1825460dff4436b03b59d301
facebook · Sep 18, 2024 · da92b08 · da92b08
1 parent d43f688
commit da92b08
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Showing 4 changed files with 90 additions and 1 deletion.
diff --git a/fboss/agent/test/agent_hw_tests/AgentPfcTests.cpp b/fboss/agent/test/agent_hw_tests/AgentPfcTests.cpp
@@ -2,8 +2,11 @@
 
 #include "fboss/agent/TxPacket.h"
 #include "fboss/agent/packet/PktFactory.h"
+#include "fboss/agent/packet/PktUtil.h"
 #include "fboss/agent/test/AgentHwTest.h"
 #include "fboss/agent/test/utils/ConfigUtils.h"
+#include "fboss/agent/test/utils/CoppTestUtils.h"
+#include "fboss/agent/test/utils/PacketSnooper.h"
 #include "fboss/agent/test/utils/PfcTestUtils.h"
 #include "fboss/lib/CommonUtils.h"
 
@@ -34,7 +37,7 @@ class AgentPfcTest : public AgentHwTest {
           0x01, 0x01, 0x00, classVector, 0x00, 0xF0, 0x00, 0xF0, 0x00, 0xF0,
           0x00, 0xF0, 0x00, 0xF0,        0x00, 0xF0, 0x00, 0xF0, 0x00, 0xF0,
       };
-      std::vector<uint8_t> padding(28, 0);
+      std::vector<uint8_t> padding(26, 0);
       payload.insert(payload.end(), padding.begin(), padding.end());
 
       // Send it out
@@ -89,4 +92,64 @@ TEST_F(AgentPfcTest, verifyPfcCounters) {
   verifyAcrossWarmBoots(setup, verify);
 }
 
+TEST_F(AgentPfcTest, verifyPfcLoopback) {
+  // TODO: Investigate if this can be extended to other ASICs
+  for (auto* asic : getAgentEnsemble()->getL3Asics()) {
+    if (asic->getAsicType() != cfg::AsicType::ASIC_TYPE_JERICHO3) {
+#if defined(GTEST_SKIP)
+      GTEST_SKIP();
+#endif
+      return;
+    }
+  }
+
+  std::vector<PortID> portIds = {masterLogicalInterfacePortIds()[0]};
+  std::vector<int> losslessPgIds = {2};
+
+  auto setup = [&]() {
+    auto cfg = getAgentEnsemble()->getCurrentConfig();
+    utility::setupPfcBuffers(cfg, portIds, losslessPgIds);
+    utility::addPuntPfcPacketAcl(
+        cfg, utility::getCoppMidPriQueueId(getAgentEnsemble()->getL3Asics()));
+    applyNewConfig(cfg);
+
+    for (const auto& switchId : getSw()->getHwAsicTable()->getSwitchIDs()) {
+      // TODO: Investigate spurious diag command failures.
+      std::string out;
+      getAgentEnsemble()->runDiagCommand(
+          "m DC3MAC_RSV_MASK MASK=0\n"
+          "m NBU_RX_MLF_DROP_FC_PKTS RX_DROP_FC_PKTS=0\n"
+          "g DC3MAC_RSV_MASK\n"
+          "g NBU_RX_MLF_DROP_FC_PKTS\n"
+          "",
+          out,
+          switchId);
+      XLOG(DBG3) << "==== Diag command output ====\n"
+                 << out << "\n==== End output ====";
+      getAgentEnsemble()->runDiagCommand("quit\n", out, switchId);
+    }
+  };
+
+  auto verify = [&]() {
+    utility::SwSwitchPacketSnooper snooper(getSw(), "snooper");
+    sendPfcFrame(portIds, 0xFF);
+
+    WITH_RETRIES({
+      auto frameRx = snooper.waitForPacket(1);
+      ASSERT_EVENTUALLY_TRUE(frameRx.has_value());
+
+      // Received packet should be unmodified.
+      folly::io::Cursor cursor(frameRx->get());
+      EthHdr ethHdr(cursor); // Consume ethernet header
+      EXPECT_EQ(cursor.readBE<uint16_t>(), 0x0101); // PFC opcode
+      EXPECT_EQ(cursor.readBE<uint16_t>(), 0x00FF); // PFC class vector
+      for (int i = 0; i < 8; ++i) {
+        EXPECT_EQ(cursor.readBE<uint16_t>(), 0x00F0); // PFC quanta
+      }
+    });
+  };
+
+  verifyAcrossWarmBoots(setup, verify);
+}
+
 } // namespace facebook::fboss
diff --git a/fboss/agent/test/utils/BUCK b/fboss/agent/test/utils/BUCK
@@ -449,6 +449,7 @@ cpp_library(
     ],
     exported_deps = [
         "fbsource//third-party/googletest:gtest",
+        ":acl_test_utils",
         "//fboss/agent:fboss-types",
         "//fboss/agent:switch_config-cpp2-types",
         "//fboss/agent:utils",

diff --git a/fboss/agent/test/utils/PfcTestUtils.cpp b/fboss/agent/test/utils/PfcTestUtils.cpp
@@ -3,6 +3,7 @@
 #include "fboss/agent/test/utils/PfcTestUtils.h"
 #include "fboss/agent/Utils.h"
 #include "fboss/agent/gen-cpp2/switch_config_types.h"
+#include "fboss/agent/test/utils/AclTestUtils.h"
 
 #include <gtest/gtest.h>
 
@@ -171,4 +172,26 @@ void setupPfcBuffers(
   cfg.bufferPoolConfigs() = std::move(bufferPoolCfgMap);
 }
 
+void addPuntPfcPacketAcl(cfg::SwitchConfig& cfg, uint16_t queueId) {
+  cfg::AclEntry entry;
+  entry.name() = "pfcMacEntry";
+  entry.actionType() = cfg::AclActionType::PERMIT;
+  entry.dstMac() = "01:80:C2:00:00:01";
+  utility::addAclEntry(&cfg, entry, utility::kDefaultAclTable());
+
+  cfg::MatchToAction matchToAction;
+  matchToAction.matcher() = "pfcMacEntry";
+  cfg::MatchAction& action = matchToAction.action().ensure();
+  action.toCpuAction() = cfg::ToCpuAction::TRAP;
+  action.sendToQueue().ensure().queueId() = queueId;
+  action.setTc().ensure().tcValue() = queueId;
+  cfg.cpuTrafficPolicy()
+      .ensure()
+      .trafficPolicy()
+      .ensure()
+      .matchToAction()
+      .ensure()
+      .push_back(matchToAction);
+}
+
 } // namespace facebook::fboss::utility
diff --git a/fboss/agent/test/utils/PfcTestUtils.h b/fboss/agent/test/utils/PfcTestUtils.h
@@ -23,4 +23,6 @@ void setupPfcBuffers(
     const std::vector<int>& losslessPgIds,
     PfcBufferParams buffer = PfcBufferParams{});
 
+void addPuntPfcPacketAcl(cfg::SwitchConfig& cfg, uint16_t queueId);
+
 } // namespace facebook::fboss::utility