From a87f5fdb3d1a23b9ad2475007c58c0969863293f Mon Sep 17 00:00:00 2001
From: Ray Ni <ray.ni@intel.com>
Date: Wed, 7 Jun 2023 16:35:46 +0800
Subject: [PATCH] UefiCpuPkg/SmmCpu: Add PcdSmmApPerfLogEnable control AP
 perf-logging

When a platform has lots of CPU cores/threads, perf-logging on every
AP produces lots of records. When this multiplies with number of SMIs
during post, the records are even more.

So, this patch adds a new PCD PcdSmmApPerfLogEnable (default TRUE)
to allow platform to turn off perf-logging on APs.

Signed-off-by: Ray Ni <ray.ni@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiaxin Wu <jiaxin.wu@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
---
 UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c        |  2 +-
 UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf |  1 +
 UefiCpuPkg/PiSmmCpuDxeSmm/SmmMpPerf.c        | 11 ++++++++++-
 UefiCpuPkg/PiSmmCpuDxeSmm/SmmMpPerf.h        |  4 +++-
 UefiCpuPkg/UefiCpuPkg.dec                    |  6 ++++++
 5 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
index bcd90f0671..8364b73242 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
@@ -784,7 +784,7 @@ BSPHandler (
   // Any SMM MP performance logging after this point will be migrated in next SMI.
   //
   PERF_CODE (
-    MigrateMpPerf (gSmmCpuPrivate->SmmCoreEntryContext.NumberOfCpus);
+    MigrateMpPerf (gSmmCpuPrivate->SmmCoreEntryContext.NumberOfCpus, CpuIndex);
     );
 
   //
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf
index 4864532c35..d864ae9101 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf
@@ -128,6 +128,7 @@
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmProfileRingBuffer             ## CONSUMES
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmFeatureControlMsrLock         ## CONSUMES
   gEfiMdeModulePkgTokenSpaceGuid.PcdDxeIplSwitchToLongMode         ## CONSUMES
+  gUefiCpuPkgTokenSpaceGuid.PcdSmmApPerfLogEnable                  ## CONSUMES
 
 [Pcd]
   gUefiCpuPkgTokenSpaceGuid.PcdCpuMaxLogicalProcessorNumber        ## SOMETIMES_CONSUMES
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmMpPerf.c b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmMpPerf.c
index f6323f9230..6d5d2b2d63 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmMpPerf.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmMpPerf.c
@@ -38,16 +38,25 @@ InitializeMpPerf (
   Migrate MP performance data to standardized performance database.
 
   @param NumberofCpus    Number of processors in the platform.
+  @param BspIndex        The index of the BSP.
 **/
 VOID
 MigrateMpPerf (
-  UINTN  NumberofCpus
+  UINTN  NumberofCpus,
+  UINTN  BspIndex
   )
 {
   UINTN  CpuIndex;
   UINTN  MpProcecureId;
 
   for (CpuIndex = 0; CpuIndex < NumberofCpus; CpuIndex++) {
+    if ((CpuIndex != BspIndex) && !FeaturePcdGet (PcdSmmApPerfLogEnable)) {
+      //
+      // Skip migrating AP performance data if AP perf-logging is disabled.
+      //
+      continue;
+    }
+
     for (MpProcecureId = 0; MpProcecureId < SMM_MP_PERF_PROCEDURE_ID (SmmMpProcedureMax); MpProcecureId++) {
       if (mSmmMpProcedurePerformance[CpuIndex].Begin[MpProcecureId] != 0) {
         PERF_START (NULL, gSmmMpPerfProcedureName[MpProcecureId], NULL, mSmmMpProcedurePerformance[CpuIndex].Begin[MpProcecureId]);
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmMpPerf.h b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmMpPerf.h
index d9f0fb9bf6..591b212c06 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmMpPerf.h
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmMpPerf.h
@@ -48,10 +48,12 @@ InitializeMpPerf (
   Migrate MP performance data to standardized performance database.
 
   @param NumberofCpus    Number of processors in the platform.
+  @param BspIndex        The index of the BSP.
 **/
 VOID
 MigrateMpPerf (
-  UINTN  NumberofCpus
+  UINTN  NumberofCpus,
+  UINTN  BspIndex
   );
 
 /**
diff --git a/UefiCpuPkg/UefiCpuPkg.dec b/UefiCpuPkg/UefiCpuPkg.dec
index d31c3b127c..5b0ac64e33 100644
--- a/UefiCpuPkg/UefiCpuPkg.dec
+++ b/UefiCpuPkg/UefiCpuPkg.dec
@@ -175,6 +175,12 @@
   # @Prompt Support SmmFeatureControl.
   gUefiCpuPkgTokenSpaceGuid.PcdSmmFeatureControlEnable|TRUE|BOOLEAN|0x32132110
 
+  ## Indicates if SMM perf logging in APs will be enabled.<BR><BR>
+  #   TRUE  - SMM perf logging in APs will be enabled.<BR>
+  #   FALSE - SMM perf logging in APs will not be enabled.<BR>
+  # @Prompt Enable SMM perf logging in APs.
+  gUefiCpuPkgTokenSpaceGuid.PcdSmmApPerfLogEnable|TRUE|BOOLEAN|0x32132114
+
 [PcdsFixedAtBuild]
   ## List of exception vectors which need switching stack.
   #  This PCD will only take into effect if PcdCpuStackGuard is enabled.