Index: llvm/test/lit.cfg.py
===================================================================
--- llvm/test/lit.cfg.py
+++ llvm/test/lit.cfg.py
@@ -42,6 +42,15 @@
 llvm_config.with_system_environment(
     ['HOME', 'INCLUDE', 'LIB', 'TMP', 'TEMP'])
 
+# Pass through environment variables used by QEMU's user mode emulation.
+# This lets us run cross compiled tests when the appropriate qemu-user
+# is installed and configured.
+llvm_config.with_system_environment(
+    ['QEMU_GDB', 'QEMU_LD_PREFIX', 'QEMU_STACK_SIZE', 'QEMU_CPU',
+     'QEMU_SET_ENV', 'QEMU_UNSET_ENV', 'QEMU_ARGV0', 'QEMU_UNAME',
+     'QEMU_GUEST_BASE', 'QEMU_RESERVED_VA', 'QEMU_LOG', 'QEMU_DFILTER',
+     'QEMU_LOG_FILENAME', 'QEMU_PAGESIZE', 'QEMU_SINGLESTEP', 'QEMU_STRACE',
+     'QEMU_RAND_SEED', 'QEMU_TRACE', 'QEMU_VERSION'])
 
 # Set up OCAMLPATH to include newly built OCaml libraries.
 top_ocaml_lib = os.path.join(config.llvm_lib_dir, 'ocaml')