Index: lld/ELF/Config.h
===================================================================
--- lld/ELF/Config.h
+++ lld/ELF/Config.h
@@ -144,6 +144,7 @@
   std::vector<llvm::StringRef> undefined;
   std::vector<SymbolVersion> dynamicList;
   std::vector<uint8_t> buildIdVector;
+  std::vector<llvm::StringRef> passPlugins;
   llvm::MapVector<std::pair<const InputSectionBase *, const InputSectionBase *>,
                   uint64_t>
       callGraphProfile;
Index: lld/ELF/Driver.cpp
===================================================================
--- lld/ELF/Driver.cpp
+++ lld/ELF/Driver.cpp
@@ -1284,6 +1284,8 @@
       error(arg->getSpelling() + ": unknown plugin option '" + arg->getValue() +
             "'");
 
+  config->passPlugins = args::getStrings(args, OPT_load_pass_plugins);
+
   // Parse -mllvm options.
   for (auto *arg : args.filtered(OPT_mllvm))
     parseClangOption(arg->getValue(), arg->getSpelling());
Index: lld/ELF/LTO.cpp
===================================================================
--- lld/ELF/LTO.cpp
+++ lld/ELF/LTO.cpp
@@ -144,6 +144,8 @@
 
   c.SampleProfile = std::string(config->ltoSampleProfile);
   c.UseNewPM = config->ltoNewPassManager;
+  for (const llvm::StringRef &PluginFN : config->passPlugins)
+    c.PassPlugins.push_back(std::string(PluginFN));
   c.DebugPassManager = config->ltoDebugPassManager;
   c.DwoDir = std::string(config->dwoDir);
 
Index: lld/ELF/Options.td
===================================================================
--- lld/ELF/Options.td
+++ lld/ELF/Options.td
@@ -714,3 +714,5 @@
     "Perform additional validation of the written dynamic relocations",
     "Do not perform additional validation of the written dynamic relocations">,
   Flags<[HelpHidden]>;
+
+defm load_pass_plugins: Eq<"load-pass-plugin", "Load passes from plugin library">;
Index: lld/test/CMakeLists.txt
===================================================================
--- lld/test/CMakeLists.txt
+++ lld/test/CMakeLists.txt
@@ -12,6 +12,9 @@
   LLVM_ENABLE_LIBXML2
   LLD_DEFAULT_LD_LLD_IS_MINGW
   LLVM_HAVE_LIBXAR
+  LLVM_BUILD_EXAMPLES
+  LLVM_ENABLE_PLUGINS
+  LLVM_BYE_LINK_INTO_TOOLS
   )
 
 configure_lit_site_cfg(
@@ -60,6 +63,11 @@
     split-file
     yaml2obj
     )
+    if (NOT WIN32)
+      list(APPEND LLD_TEST_DEPS
+        Bye
+        )
+    endif()
 endif()
 
 add_lit_testsuite(check-lld "Running lld test suite"
Index: lld/test/ELF/lto/ltopasses-extension.ll
===================================================================
--- /dev/null
+++ lld/test/ELF/lto/ltopasses-extension.ll
@@ -0,0 +1,14 @@
+; REQUIRES: x86, plugins, examples
+; UNSUPPORTED: windows
+; RUN: opt -module-summary %s -o %t.o
+; RUN: ld.lld -%loadnewpmbye --lto-newpm-passes="goodbye" -mllvm=%loadbye -mllvm=-wave-goodbye %t.o 2>&1 | FileCheck %s
+; RUN: ld.lld -mllvm=%loadbye -mllvm=-wave-goodbye %t.o --plugin-opt=legacy-pass-manager 2>&1 | FileCheck %s
+; CHECK: Bye
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+@junk = global i32 0
+
+define i32* @somefunk() {
+  ret i32* @junk
+}
Index: lld/test/lit.cfg.py
===================================================================
--- lld/test/lit.cfg.py
+++ lld/test/lit.cfg.py
@@ -115,6 +115,24 @@
 if config.sizeof_void_p == 8:
     config.available_features.add("llvm-64-bits")
 
+if config.has_plugins:
+    config.available_features.add('plugins')
+
+if config.build_examples:
+    config.available_features.add('examples')
+
+if config.linked_bye_extension:
+    config.substitutions.append(('%loadbye', ''))
+    config.substitutions.append(('%loadnewpmbye', ''))
+else:
+    config.substitutions.append(('%loadbye',
+                                 '-load={}/Bye{}'.format(config.llvm_shlib_dir,
+                                                         config.llvm_shlib_ext)))
+    config.substitutions.append(('%loadnewpmbye',
+                                 '-load-pass-plugin={}/Bye{}'
+                                 .format(config.llvm_shlib_dir,
+                                         config.llvm_shlib_ext)))
+
 tar_executable = lit.util.which('tar', config.environment['PATH'])
 if tar_executable:
     env = os.environ
Index: lld/test/lit.site.cfg.py.in
===================================================================
--- lld/test/lit.site.cfg.py.in
+++ lld/test/lit.site.cfg.py.in
@@ -5,6 +5,8 @@
 config.have_dia_sdk = lit.util.pythonize_bool("@LLVM_ENABLE_DIA_SDK@")
 config.llvm_src_root = "@LLVM_SOURCE_DIR@"
 config.llvm_obj_root = "@LLVM_BINARY_DIR@"
+config.llvm_shlib_dir = "@SHLIBDIR@"
+config.llvm_shlib_ext = "@SHLIBEXT@"
 config.llvm_tools_dir = "@LLVM_TOOLS_DIR@"
 config.llvm_libs_dir = "@LLVM_LIBS_DIR@"
 config.lit_tools_dir = "@LLVM_LIT_TOOLS_DIR@"
@@ -19,6 +21,9 @@
 config.have_libxml2 = @LLVM_ENABLE_LIBXML2@
 config.sizeof_void_p = @CMAKE_SIZEOF_VOID_P@
 config.ld_lld_default_mingw = @LLD_DEFAULT_LD_LLD_IS_MINGW@
+config.build_examples = @LLVM_BUILD_EXAMPLES@
+config.has_plugins = @LLVM_ENABLE_PLUGINS@
+config.linked_bye_extension = @LLVM_BYE_LINK_INTO_TOOLS@
 
 # Support substitution of the tools and libs dirs with user parameters. This is
 # used when we can't determine the tool dir at configuration time.
Index: llvm/examples/Bye/Bye.cpp
===================================================================
--- llvm/examples/Bye/Bye.cpp
+++ llvm/examples/Bye/Bye.cpp
@@ -50,6 +50,11 @@
     [](const llvm::PassManagerBuilder &Builder,
        llvm::legacy::PassManagerBase &PM) { PM.add(new LegacyBye()); });
 
+static llvm::RegisterStandardPasses RegisterByeLTO(
+    llvm::PassManagerBuilder::EP_ModuleOptimizerEarly,
+    [](const llvm::PassManagerBuilder &Builder,
+       llvm::legacy::PassManagerBase &PM) { PM.add(new LegacyBye()); });
+
 /* New PM Registration */
 llvm::PassPluginLibraryInfo getByePluginInfo() {
   return {LLVM_PLUGIN_API_VERSION, "Bye", LLVM_VERSION_STRING,