diff --git a/lld/COFF/Config.h b/lld/COFF/Config.h
--- a/lld/COFF/Config.h
+++ b/lld/COFF/Config.h
@@ -223,6 +223,9 @@
   // Used for /lto-cs-profile-path
   llvm::StringRef ltoCSProfileFile;
 
+  // Used for /lto-cspgo-warn-mismatch:
+  bool ltoCSPGOWarnMismatch = true;
+
   // Used for /call-graph-ordering-file:
   llvm::MapVector<std::pair<const SectionChunk *, const SectionChunk *>,
                   uint64_t>
diff --git a/lld/COFF/Driver.cpp b/lld/COFF/Driver.cpp
--- a/lld/COFF/Driver.cpp
+++ b/lld/COFF/Driver.cpp
@@ -1744,6 +1744,8 @@
   config->ltoCSProfileGenerate = args.hasArg(OPT_lto_cs_profile_generate);
   config->ltoCSProfileFile = args.getLastArgValue(OPT_lto_cs_profile_file);
   // Handle miscellaneous boolean flags.
+  config->ltoCSPGOWarnMismatch = args.hasFlag(
+      OPT_lto_cspgo_warn_mismatch, OPT_lto_cspgo_warn_mismatch_no, true);
   config->allowBind = args.hasFlag(OPT_allowbind, OPT_allowbind_no, true);
   config->allowIsolation =
       args.hasFlag(OPT_allowisolation, OPT_allowisolation_no, true);
diff --git a/lld/COFF/LTO.cpp b/lld/COFF/LTO.cpp
--- a/lld/COFF/LTO.cpp
+++ b/lld/COFF/LTO.cpp
@@ -87,6 +87,7 @@
   c.DebugPassManager = config->ltoDebugPassManager;
   c.CSIRProfile = std::string(config->ltoCSProfileFile);
   c.RunCSIRInstr = config->ltoCSProfileGenerate;
+  c.CSPGOWarnMismatch = config->ltoCSPGOWarnMismatch;
 
   if (config->saveTemps)
     checkError(c.addSaveTemps(std::string(config->outputFile) + ".",
diff --git a/lld/COFF/Options.td b/lld/COFF/Options.td
--- a/lld/COFF/Options.td
+++ b/lld/COFF/Options.td
@@ -243,6 +243,10 @@
     HelpText<"Perform context sensitive PGO instrumentation">;
 def lto_cs_profile_file : P<"lto-cs-profile-file",
     "Context sensitive profile file path">;
+defm lto_cspgo_warn_mismatch: B<
+     "lto-cspgo-warn-mismatch",
+     "turn on warnings about profile cfg mismatch (default)>",
+     "turn off warnings about profile cfg mismatch">;
 def dash_dash_version : Flag<["--"], "version">,
   HelpText<"Display the version number and exit">;
 def threads
diff --git a/llvm/include/llvm/LTO/Config.h b/llvm/include/llvm/LTO/Config.h
--- a/llvm/include/llvm/LTO/Config.h
+++ b/llvm/include/llvm/LTO/Config.h
@@ -70,6 +70,10 @@
   /// Run PGO context sensitive IR instrumentation.
   bool RunCSIRInstr = false;
 
+  /// Turn on/off the warning about a hash mismatch in the context sensitive
+  /// PGO profile data.
+  bool CSPGOWarnMismatch = true;
+
   /// Asserts whether we can assume whole program visibility during the LTO
   /// link.
   bool HasWholeProgramVisibility = false;
diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -74,6 +74,10 @@
     cl::desc("Assume the input has already undergone ThinLTO function "
              "importing and the other pre-optimization pipeline changes."));
 
+// Command line option to turn off/on warnings for pgo profile mismatch.
+// Defined in Transforms/PGOInstrumentation.cpp:  -no-pgo-warn-mismatch
+extern cl::opt<bool> NoPGOWarnMismatch;
+
 LLVM_ATTRIBUTE_NORETURN static void reportOpenError(StringRef Path, Twine Msg) {
   errs() << "failed to open " << Path << ": " << Msg << '\n';
   errs().flush();
@@ -221,6 +225,7 @@
     PGOOpt = PGOOptions(Conf.CSIRProfile, "", Conf.ProfileRemapping,
                         PGOOptions::IRUse, PGOOptions::CSIRUse,
                         Conf.AddFSDiscriminator);
+    NoPGOWarnMismatch = !Conf.CSPGOWarnMismatch;
   } else if (Conf.AddFSDiscriminator) {
     PGOOpt = PGOOptions("", "", "", PGOOptions::NoAction,
                         PGOOptions::NoCSAction, true);
diff --git a/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp b/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
--- a/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
+++ b/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
@@ -200,7 +200,7 @@
 
 // Command line option to enable/disable the warning about a hash mismatch in
 // the profile data.
-static cl::opt<bool>
+cl::opt<bool>
     NoPGOWarnMismatch("no-pgo-warn-mismatch", cl::init(false), cl::Hidden,
                       cl::desc("Use this option to turn off/on "
                                "warnings about profile cfg mismatch."));