Index: lldb/docs/resources/test.rst
===================================================================
--- lldb/docs/resources/test.rst
+++ lldb/docs/resources/test.rst
@@ -418,3 +418,12 @@
    --arch=i686 --executable D:/src/llvmbuild/ninja/bin/lldb.exe -s D:/src/llvmbuild/ninja/lldb-test-traces -u CXXFLAGS -u CFLAGS --enable-crash-dialog -C d:\src\llvmbuild\ninja_release\bin\clang.exe -p TestPaths.py D:\src\llvm\tools\lldb\packages\Python\lldbsuite\test --no-multiprocess
 
 .. [#] `https://lldb.llvm.org/python_reference/lldb.SBTarget-class.html#BreakpointCreateByName <https://lldb.llvm.org/python_reference/lldb.SBTarget-class.html#BreakpointCreateByName>`_
+
+Testing LLDB in QEMU System Emulation Environment
+-------------------------------------------------
+
+QEMU can be used to test LLDB in an emulation environment in the absence of
+actual hardware. QEMU helper scripts and README.txt document can be found under
+llvm-project/lldb/scripts/lldb-test-qemu which can help setup a virtual testing
+environment for LLDB using QEMU. These scripts currently work with Arm or
+AArch64, but support for other architectures can be added easily.
Index: lldb/scripts/lldb-test-qemu/README.txt
===================================================================
--- /dev/null
+++ lldb/scripts/lldb-test-qemu/README.txt
@@ -0,0 +1,119 @@
+----------------------------------------------------------------------
+  LLDB testing on Linux using QEMU system mode emulation
+----------------------------------------------------------------------
+
+QEMU can be used to test LLDB in an emulation environment in the absence of
+actual hardware. This documents will help setup a QEMU system mode emulation
+environment for testing LLDB.
+
+The scripts under llvm-project/lldb/scripts/lldb-test-qemu can quickly help
+setup a virtual LLDB testing environment using QEMU. The scripts currently work
+with Arm or AArch64, but support for other architectures can be easily added.
+
+We have written helper scripts under llvm-project/lldb/tools/lldb-test-qemu
+which can help quickly setup a Arm or AArch64 testing environment using QEMU.
+
+* setup.sh is used to build the Linux kernel image and QEMU system emulation
+  executable(s) from source.
+
+* rootfs.sh is used to generate Ubuntu root file system images to be used for
+  QEMU system mode emulation.
+
+* run-qemu.sh utilizes QEMU to boot a Linux kernel image with a root file
+  system image.
+
+Once we have booted our kernel we can run lldb-server in emulation environment.
+Ubuntu Bionic/Focal x86_64 host was used to test all the instructions in this
+document. Please update it according to your host distribution/architecture.
+
+Note: sudo permissions are needed to run above scripts.
+
+Given below are some common examples of common use-cases of LLDB QEMU testing
+helper scripts:
+
+--------------------------------------------------------------------------------
+  Create Ubuntu root file system image for QEMU system emulation with rootfs.sh
+--------------------------------------------------------------------------------
+
+* Example: generate Ubuntu Bionic (armhf) rootfs image of size 1 GB
+  bash rootfs.sh --arch armhf --distro bionic --size 1G
+
+* Example: generate Ubuntu Focal (arm64) rootfs image of size 2 GB
+  bash rootfs.sh --arch arm64 --distro focal --size 2G
+
+* rootfs.sh has been tested for generating Ubuntu Bionic and Focal images but
+  they can be used to generate rootfs images of other Debian Linux distribution.
+
+* rootfs.sh defaults username of generated image to your current username on
+  host computer.
+
+-----------------------------------------------------------------------
+  Build QEMU or cross compile Linux kernel from source using setup.sh
+-----------------------------------------------------------------------
+
+* Example: Build QEMU binaries and Arm/AArch64 Linux kernel image
+  bash setup.sh --qemu --kernel arm
+  bash setup.sh --qemu --kernel arm64
+
+* Example: Build Linux kernel image only
+  bash setup.sh --kernel arm
+  bash setup.sh --kernel arm64
+
+* Example: Build qemu-system-arm and qemu-system-aarch64 binaries.
+  bash setup.sh --qemu
+
+* Example: Remove qemu.git, linux.git and linux.build from working directory
+  bash setup.sh --clean
+
+--------------------------------------------------------------
+  Run QEMU Arm or AArch64 system emulation using run-qemu.sh
+--------------------------------------------------------------
+run-qemu.sh has following dependencies:
+
+* Follow https://wiki.qemu.org/Documentation/Networking/NAT and set up bridge
+  networking for QEMU.
+
+* Make sure /etc/qemu-ifup script is available with executable permissions.
+
+* QEMU binaries must be built from source using setup.sh or provided via --qemu
+  commandline argument.
+
+* Linux kernel image must be built from source using setup.sh or provided via
+  --kernel commandline argument.
+
+* linux.build and qemu.git folder must be present in current directory if
+  setup.sh was used to build Linux kernel and QEMU binaries.
+
+* --sve option will enable AArch64 SVE mode.
+
+* Example: Run QEMU Arm or AArch64 system emulation using run-qemu.sh
+  sudo bash run-qemu.sh --arch arm --rootfs <path of rootfs image>
+  sudo bash run-qemu.sh --arch arm64 --rootfs <path of rootfs image>
+
+* Example: Run QEMU with kernel image and qemu binary provided using commandline
+  sudo bash run-qemu.sh --arch arm64 --rootfs <path of rootfs image> \
+  --kernel <path of Linux kernel image> --qemu <path of QEMU binary>
+
+----------------------------------------------------------------------
+  Steps for running lldb-server in QEMU system emulation environment
+----------------------------------------------------------------------
+
+1) Make sure bridge networking is enabled between host machine and QEMU VM
+
+2) Find out ip address assigned to eth0 in emulation environment
+
+3) Setup ssh access between host machine and emulation environment
+
+4) Login emulation environment and install dependencies
+   sudo apt install python-dev libedit-dev libncurses5-dev libexpat1-dev
+
+5) Cross compile LLDB server for AArch64 Linux
+   Please visit https://lldb.llvm.org/resources/build.html for instructions
+   on how to cross compile LLDB server.
+
+6) Transfer LLDB server executable to emulation environment
+   scp lldb-server username@ip-address-of-emulation-environment:/home/username
+
+7) Run lldb-server inside QEMU VM
+
+8) Try connecting to lldb-server running inside QEMU VM with selected ip:port
Index: lldb/scripts/lldb-test-qemu/rootfs.sh
===================================================================
--- /dev/null
+++ lldb/scripts/lldb-test-qemu/rootfs.sh
@@ -0,0 +1,98 @@
+#!/bin/bash
+
+set -e
+
+print_usage() {
+  echo "Usage:"
+  echo "Usage: $(basename $0) [options]"
+  echo -e "Creates a Ubuntu root file system image.\n"
+  echo -e "  --help\t\t\tDisplay this information."
+  echo -e "  --arch {armhf|arm64}\t\tSelects architecture of rootfs image."
+  echo -e "  --distro {bionic|focal}\tSelects Ubuntu distribution of rootfs image."
+  echo -e "  --size n{K|M|G}\t\tSets size of rootfs image to n Kilo, Mega or Giga bytes."
+  exit "$1"
+}
+
+invalid_arg() {
+  echo "ERROR: Unrecognized argument: $1" >&2
+  print_usage 1
+}
+
+update_repositories() {
+  echo -e "\nUpdating apt repositories. "
+  echo -e "\nPress 'y' to continue or any other key to exit..."
+  read -s -n 1 user_input
+  if [[ $user_input == 'Y' ]] || [[ $user_input == 'y' ]]; then
+    sudo apt update
+  else
+    exit
+  fi
+}
+
+# Parse options
+while [[ $# -gt 0 ]]; do
+  case "${END_OF_OPT}${1}" in
+    --help)     print_usage 0 ;;
+    --arch)     rfs_arch=$2;   shift;;
+    --distro)   rfs_distro=$2; shift;;
+    --size)     rfs_size=$2;   shift;;
+    *)          invalid_arg "$1" ;;
+  esac
+  shift
+done
+
+if [ -z "$rfs_arch" ]; then
+  echo "Missing architecture"
+  print_usage 1
+fi
+if [ -z "$rfs_distro" ]; then
+  echo "Missing distribution"
+  print_usage 1
+fi
+if [ -z "$rfs_size" ]; then
+  echo "Missing size"
+  print_usage 1
+fi
+
+if [[ "$rfs_arch" != "arm64" && "$rfs_arch" != "armhf" ]]; then
+  echo "Invalid architecture: $rfs_arch"
+  print_usage 1
+fi
+
+pat='^[0-9]+[K|M|G]$'
+if [[ ! $rfs_size =~ $pat ]]; then
+  echo "Invalid size: $rfs_size"
+  print_usage 1
+fi
+
+update_repositories
+
+echo "Installing build dependencies ..."
+sudo apt-get install debootstrap qemu-user-static schroot qemu-utils
+
+image_name=$rfs_distro-$rfs_arch-"rootfs"
+echo "Creating $rfs_distro ($rfs_arch) root file system ..."
+echo "Image name: $image_name.img"
+echo "Image size: $rfs_size"
+
+qemu-img create $image_name.img $rfs_size
+
+mkfs.ext4 $image_name.img
+mkdir $image_name.dir
+sudo mount -o loop $image_name.img $image_name.dir
+
+sudo qemu-debootstrap --arch $rfs_arch $rfs_distro $image_name.dir
+
+sudo chroot $image_name.dir locale-gen en_US.UTF-8
+
+sudo chroot $image_name.dir sed -i \
+'s/main/main restricted multiverse universe/g' /etc/apt/sources.list
+
+sudo chroot $image_name.dir sed -i '$ a\nameserver 8.8.8.8' /etc/resolv.conf
+
+sudo chroot $image_name.dir apt update
+sudo chroot $image_name.dir apt -y install ssh bash-completion
+sudo chroot $image_name.dir adduser --gecos "" $USER
+sudo chroot $image_name.dir adduser $USER sudo
+sudo umount $image_name.dir
+rmdir $image_name.dir
Index: lldb/scripts/lldb-test-qemu/run-qemu.sh
===================================================================
--- /dev/null
+++ lldb/scripts/lldb-test-qemu/run-qemu.sh
@@ -0,0 +1,112 @@
+#!/bin/bash
+
+print_usage() {
+  echo "Usage: $(basename $0) --arch [arm|arm64] [options]"
+  echo -e "Starts QEMU system mode emulation for the architecture.\n"
+  echo -e "  --help\t\t\tDisplay this information."
+  echo -e "  --arch {arm|arm64}\t\tSelects architecture QEMU system emulation."
+  echo -e "  --sve {path}\t\t\tEnables AArch64 SVE mode.\n"
+  echo -e "  --rootfs {path}\t\tPath of root file system image."
+  echo -e "  --qemu {path}\t\t\tPath of pre-installed qemu-system-* executable."
+  echo -e "  --kernel {path}\t\tPath of Linux kernel prebuilt image.\n"
+  echo -e "By default this utility will use:"
+  echo -e "  QEMU image built from source in qemu.git directory"
+  echo -e "  Linux kernel image from linux.build/(arm or arm64) directory."
+  echo -e "Custom Linux kernel image or QEMU binary can be provided using commandline."
+  exit "$1"
+}
+
+invalid_arg() {
+  echo "ERROR: Unrecognized argument: $1" >&2
+  print_usage 1
+}
+
+run_qemu() {
+  QEMU_CORES=2
+  QEMU_MEMORY=1024
+
+  $QEMU_BIN \
+  -cpu $QEMU_CPU \
+  -m $QEMU_MEMORY \
+  -smp $QEMU_CORES \
+  -kernel $KERNEL_IMG \
+  -machine $QEMU_MACHINE \
+  -drive file=$ROOTFS_IMG,if=none,format=raw,id=hd0 \
+  -device virtio-blk-device,drive=hd0 \
+  -append "root=/dev/vda rw ip=dhcp mem=1024M raid=noautodetect  \
+  crashkernel=128M rootwait console=ttyAMA0 devtmpfs.mount=0" \
+  -netdev type=tap,id=net0 \
+  -device virtio-net-device,netdev=net0 \
+  -nographic
+}
+
+# Parse options
+while [[ $# -gt 0 ]]; do
+  case "${END_OF_OPT}${1}" in
+    --arch)     ARCH=$2; shift;;
+    --rootfs)   ROOTFS_IMG=$2; shift;;
+    --kernel)   KERNEL_IMG=$2; shift;;
+    --qemu)     QEMU_BIN=$2; shift;;
+    --sve)      SVE=1;;
+    --help)     print_usage 0 ;;
+    *)          invalid_arg "$1" ;;
+  esac
+  shift
+done
+
+if [ "$ARCH" == "arm64" ] && [ "$ARCH" == "arm" ]; then
+  echo "Invalid architecture: $ARCH"
+  print_usage 1
+fi
+
+if [[ ! -f "$ROOTFS_IMG" ]]; then
+  echo "No root file system image image available for emulation."
+  exit
+fi
+
+if [[ ! -f "$KERNEL_IMG" ]]; then
+  KERNEL_IMG_PATH=$(pwd)/linux.build/"$ARCH"/arch/"$ARCH"/boot/
+
+  if [[ ! -d "$KERNEL_IMG_PATH" ]]; then
+    echo "No Linux kernel image available for emulation."
+    exit
+  fi
+
+  if [[ "$ARCH" == "arm" ]]; then
+    KERNEL_IMG=$KERNEL_IMG_PATH/zImage
+  elif [[ "$ARCH" == "arm64" ]]; then
+    KERNEL_IMG=$KERNEL_IMG_PATH/Image
+  fi
+fi
+
+if [[ ! -f "$QEMU_BIN" ]]; then
+  if [[ "$ARCH" == "arm" ]]; then
+    QEMU_BIN=$(pwd)/qemu.git/arm-softmmu/qemu-system-arm
+  elif [[ "$ARCH" == "arm64" ]]; then
+    QEMU_BIN=$(pwd)/qemu.git/aarch64-softmmu/qemu-system-aarch64
+  fi
+
+  if [[ ! -f "$QEMU_BIN" ]]; then
+    echo "QEMU $ARCH system emulation executable not found."
+    exit
+  fi
+fi
+
+if [[ "$ARCH" == "arm" ]]; then
+  QEMU_MACHINE="virt,highmem=off"
+  QEMU_CPU="cortex-a15"
+
+  if [[ $SVE ]]; then
+    echo "warning: --sve is supported by AArch64 targets only"
+  fi
+elif [[ "$ARCH" == "arm64" ]]; then
+  QEMU_MACHINE=virt
+  QEMU_SVE_MAX_VQ=4
+  QEMU_CPU="cortex-a53"
+
+  if [[ $SVE ]]; then
+    QEMU_CPU="max,sve-max-vq=$QEMU_SVE_MAX_VQ"
+  fi
+fi
+
+run_qemu
Index: lldb/scripts/lldb-test-qemu/setup.sh
===================================================================
--- /dev/null
+++ lldb/scripts/lldb-test-qemu/setup.sh
@@ -0,0 +1,151 @@
+#!/bin/bash
+
+print_usage() {
+  echo "Usage: $(basename $0) [options]"
+  echo -e "Builds QEMU and Linux kernel from source.\n"
+  echo -e "  --help\t\t\tDisplay this information."
+  echo -e "  --kernel {arm|arm64}\t\tBuild Linux kernel for the architecture."
+  echo -e "  --qemu\t\t\tBuild QEMU from source."
+  echo -e "  --clean\t\t\tRemove qemu.git and linux.git directories in current directory."
+  exit "$1"
+}
+
+update_repositories() {
+  echo -e "\nUpdating apt repositories. "
+  echo -e "\nPress 'y' to continue or any other key to exit..."
+  read -s -n 1 user_input
+  if [[ $user_input == 'Y' ]] || [[ $user_input == 'y' ]]; then
+    sudo apt update
+  else
+    exit
+  fi
+}
+
+check_dir_exists() {
+  user_input=
+  if [ -d "$1" ]; then
+    echo -e "\n$1 already exists in working directory and will not be updated."
+    echo -e "\nPress 'y' to continue or any other key to exit..."
+    read -s -n 1 user_input
+    if [[ $user_input != 'Y' ]] && [[ $user_input != 'y' ]]; then
+      exit
+    fi
+  fi
+}
+
+invalid_arg() {
+  echo "ERROR: Unrecognized argument: $1" >&2
+  print_usage 1
+}
+
+build_qemu() {
+  echo "Installing QEMU build dependencies ..."
+  sudo apt install git python3-dev libsdl1.2-dev build-essential libpixman-1-dev
+
+  # Checkout source code
+  check_dir_exists "qemu.git"
+  if [ ! -d "qemu.git" ]; then
+    git clone --depth 1 git://git.qemu.org/qemu.git qemu.git
+  fi
+
+  cd qemu.git
+  # We are going to build QEMU Arm and AArch64 system mode emulation.
+  # ./configure --help emits a list of other possible targets supported by QEMU.
+  ./configure --target-list=arm-softmmu,aarch64-softmmu
+  make -j`getconf _NPROCESSORS_ONLN`
+}
+
+build_linux() {
+  echo "Installing Linux kernel build dependencies ..."
+  sudo apt install git bison flex build-essential libssl-dev bc
+
+  check_dir_exists "linux.git"
+
+  if [ ! -d "linux.git" ]; then
+    git clone --depth 1 \
+    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git linux.git
+  fi
+
+  cd linux.git
+  make mrproper
+
+  if [[ "$1" == "arm" ]]; then
+    echo "Installing gcc-arm-linux-gnueabihf ..."
+    sudo apt install gcc-arm-linux-gnueabihf
+
+    # Configure kernel_branch=master arch=arm config=vexpress_defconfig
+    make O=../linux.build/arm ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- \
+    vexpress_defconfig
+
+    # Trigger Arm kernel build
+    make -j`getconf _NPROCESSORS_ONLN` O=../linux.build/arm ARCH=arm \
+    CROSS_COMPILE=arm-linux-gnueabihf-
+  elif [[ "$1" == "arm64" ]]; then
+    echo "Installing gcc-aarch64-linux-gnu ..."
+    sudo apt install gcc-aarch64-linux-gnu
+
+    # Configure kernel_branch=master arch=arm64 config=defconfig
+    make O=../linux.build/arm64 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- \
+    defconfig
+
+    # Trigger AArch64 kernel build
+    make -j`getconf _NPROCESSORS_ONLN` O=../linux.build/arm64 ARCH=arm64 \
+    CROSS_COMPILE=aarch64-linux-gnu-
+  else
+    echo "ERROR: Unrecognized architecture: $1" >&2
+    print_usage 1
+    exit
+  fi
+}
+
+clean() {
+  if [ -d "linux.git" ]; then
+    echo "Removing linux.git ..."
+    rm -rf linux.git
+  fi
+
+  if [ -d "linux.build" ]; then
+    echo "Removing linux.build ..."
+    rm -rf linux.build
+  fi
+
+  if [ -d "qemu.git" ]; then
+    echo "Removing qemu.git ..."
+    rm -rf qemu.git
+  fi
+
+  exit
+}
+
+# Parse options
+while [[ $# -gt 0 ]]; do
+  case "${END_OF_OPT}${1}" in
+    -h|--help)   print_usage 0 ;;
+    -k|--kernel)
+      if [ "$2" == "arm64" ] || [ "$2" == "arm" ]; then
+      KERNEL_ARCH=$2
+      else
+        invalid_arg "$2"
+      fi
+      shift;;
+    -q|--qemu)
+        QEMU=1;;
+    -c|--clean)  clean ;;
+    *)           invalid_arg "$1" ;;
+  esac
+  shift
+done
+
+update_repositories
+
+if [ "$KERNEL_ARCH" != "" ]; then
+  pushd .
+  build_linux $KERNEL_ARCH
+  popd
+fi
+
+if [[ $QEMU -eq 1 ]]; then
+  pushd .
+  build_qemu
+  popd
+fi