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+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+set -u
+set -e
+
+# This script currently only works for x86_64, as
+# it is based on the VM image used by the BPF CI which is
+# x86_64.
+QEMU_BINARY="${QEMU_BINARY:="qemu-system-x86_64"}"
+X86_BZIMAGE="arch/x86/boot/bzImage"
+DEFAULT_COMMAND="./test_progs"
+MOUNT_DIR="mnt"
+ROOTFS_IMAGE="root.img"
+OUTPUT_DIR="$HOME/.bpf_selftests"
+KCONFIG_URL="https://raw.githubusercontent.com/libbpf/libbpf/master/travis-ci/vmtest/configs/latest.config"
+INDEX_URL="https://raw.githubusercontent.com/libbpf/libbpf/master/travis-ci/vmtest/configs/INDEX"
+NUM_COMPILE_JOBS="$(nproc)"
+
+usage()
+{
+ cat <<EOF
+Usage: $0 [-k] [-i] [-d <output_dir>] -- [<command>]
+
+<command> is the command you would normally run when you are in
+tools/testing/selftests/bpf. e.g:
+
+ $0 -- ./test_progs -t test_lsm
+
+If no command is specified, "${DEFAULT_COMMAND}" will be run by
+default.
+
+If you build your kernel using KBUILD_OUTPUT= or O= options, these
+can be passed as environment variables to the script:
+
+ O=<kernel_build_path> $0 -- ./test_progs -t test_lsm
+
+or
+
+ KBUILD_OUTPUT=<kernel_build_path> $0 -- ./test_progs -t test_lsm
+
+Options:
+
+ -k) "Keep the kernel", i.e. don't recompile the kernel if it exists.
+ -i) Update the rootfs image with a newer version.
+ -d) Update the output directory (default: ${OUTPUT_DIR})
+ -j) Number of jobs for compilation, similar to -j in make
+ (default: ${NUM_COMPILE_JOBS})
+EOF
+}
+
+unset URLS
+populate_url_map()
+{
+ if ! declare -p URLS &> /dev/null; then
+ # URLS contain the mapping from file names to URLs where
+ # those files can be downloaded from.
+ declare -gA URLS
+ while IFS=$'\t' read -r name url; do
+ URLS["$name"]="$url"
+ done < <(curl -Lsf ${INDEX_URL})
+ fi
+}
+
+download()
+{
+ local file="$1"
+
+ if [[ ! -v URLS[$file] ]]; then
+ echo "$file not found" >&2
+ return 1
+ fi
+
+ echo "Downloading $file..." >&2
+ curl -Lsf "${URLS[$file]}" "${@:2}"
+}
+
+newest_rootfs_version()
+{
+ {
+ for file in "${!URLS[@]}"; do
+ if [[ $file =~ ^libbpf-vmtest-rootfs-(.*)\.tar\.zst$ ]]; then
+ echo "${BASH_REMATCH[1]}"
+ fi
+ done
+ } | sort -rV | head -1
+}
+
+download_rootfs()
+{
+ local rootfsversion="$1"
+ local dir="$2"
+
+ if ! which zstd &> /dev/null; then
+ echo 'Could not find "zstd" on the system, please install zstd'
+ exit 1
+ fi
+
+ download "libbpf-vmtest-rootfs-$rootfsversion.tar.zst" |
+ zstd -d | sudo tar -C "$dir" -x
+}
+
+recompile_kernel()
+{
+ local kernel_checkout="$1"
+ local make_command="$2"
+
+ cd "${kernel_checkout}"
+
+ ${make_command} olddefconfig
+ ${make_command}
+}
+
+mount_image()
+{
+ local rootfs_img="${OUTPUT_DIR}/${ROOTFS_IMAGE}"
+ local mount_dir="${OUTPUT_DIR}/${MOUNT_DIR}"
+
+ sudo mount -o loop "${rootfs_img}" "${mount_dir}"
+}
+
+unmount_image()
+{
+ local mount_dir="${OUTPUT_DIR}/${MOUNT_DIR}"
+
+ sudo umount "${mount_dir}" &> /dev/null
+}
+
+update_selftests()
+{
+ local kernel_checkout="$1"
+ local selftests_dir="${kernel_checkout}/tools/testing/selftests/bpf"
+
+ cd "${selftests_dir}"
+ ${make_command}
+
+ # Mount the image and copy the selftests to the image.
+ mount_image
+ sudo rm -rf "${mount_dir}/root/bpf"
+ sudo cp -r "${selftests_dir}" "${mount_dir}/root"
+ unmount_image
+}
+
+update_init_script()
+{
+ local init_script_dir="${OUTPUT_DIR}/${MOUNT_DIR}/etc/rcS.d"
+ local init_script="${init_script_dir}/S50-startup"
+ local command="$1"
+ local log_file="$2"
+
+ mount_image
+
+ if [[ ! -d "${init_script_dir}" ]]; then
+ cat <<EOF
+Could not find ${init_script_dir} in the mounted image.
+This likely indicates a bad rootfs image, Please download
+a new image by passing "-i" to the script
+EOF
+ exit 1
+
+ fi
+
+ sudo bash -c "cat >${init_script}" <<EOF
+#!/bin/bash
+
+{
+ cd /root/bpf
+ echo ${command}
+ stdbuf -oL -eL ${command}
+} 2>&1 | tee /root/${log_file}
+poweroff -f
+EOF
+
+ sudo chmod a+x "${init_script}"
+ unmount_image
+}
+
+create_vm_image()
+{
+ local rootfs_img="${OUTPUT_DIR}/${ROOTFS_IMAGE}"
+ local mount_dir="${OUTPUT_DIR}/${MOUNT_DIR}"
+
+ rm -rf "${rootfs_img}"
+ touch "${rootfs_img}"
+ chattr +C "${rootfs_img}" >/dev/null 2>&1 || true
+
+ truncate -s 2G "${rootfs_img}"
+ mkfs.ext4 -q "${rootfs_img}"
+
+ mount_image
+ download_rootfs "$(newest_rootfs_version)" "${mount_dir}"
+ unmount_image
+}
+
+run_vm()
+{
+ local kernel_bzimage="$1"
+ local rootfs_img="${OUTPUT_DIR}/${ROOTFS_IMAGE}"
+
+ if ! which "${QEMU_BINARY}" &> /dev/null; then
+ cat <<EOF
+Could not find ${QEMU_BINARY}
+Please install qemu or set the QEMU_BINARY environment variable.
+EOF
+ exit 1
+ fi
+
+ ${QEMU_BINARY} \
+ -nodefaults \
+ -display none \
+ -serial mon:stdio \
+ -cpu kvm64 \
+ -enable-kvm \
+ -smp 4 \
+ -m 2G \
+ -drive file="${rootfs_img}",format=raw,index=1,media=disk,if=virtio,cache=none \
+ -kernel "${kernel_bzimage}" \
+ -append "root=/dev/vda rw console=ttyS0,115200"
+}
+
+copy_logs()
+{
+ local mount_dir="${OUTPUT_DIR}/${MOUNT_DIR}"
+ local log_file="${mount_dir}/root/$1"
+
+ mount_image
+ sudo cp ${log_file} "${OUTPUT_DIR}"
+ sudo rm -f ${log_file}
+ unmount_image
+}
+
+is_rel_path()
+{
+ local path="$1"
+
+ [[ ${path:0:1} != "/" ]]
+}
+
+main()
+{
+ local script_dir="$(cd -P -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd -P)"
+ local kernel_checkout=$(realpath "${script_dir}"/../../../../)
+ local log_file="$(date +"bpf_selftests.%Y-%m-%d_%H-%M-%S.log")"
+ # By default the script searches for the kernel in the checkout directory but
+ # it also obeys environment variables O= and KBUILD_OUTPUT=
+ local kernel_bzimage="${kernel_checkout}/${X86_BZIMAGE}"
+ local command="${DEFAULT_COMMAND}"
+ local kernel_recompile="yes"
+ local update_image="no"
+
+ while getopts 'hkid:j:' opt; do
+ case ${opt} in
+ k)
+ kernel_recompile="no"
+ ;;
+ i)
+ update_image="yes"
+ ;;
+ d)
+ OUTPUT_DIR="$OPTARG"
+ ;;
+ j)
+ NUM_COMPILE_JOBS="$OPTARG"
+ ;;
+ h)
+ usage
+ exit 0
+ ;;
+ \? )
+ echo "Invalid Option: -$OPTARG"
+ usage
+ exit 1
+ ;;
+ : )
+ echo "Invalid Option: -$OPTARG requires an argument"
+ usage
+ exit 1
+ ;;
+ esac
+ done
+ shift $((OPTIND -1))
+
+ if [[ $# -eq 0 ]]; then
+ echo "No command specified, will run ${DEFAULT_COMMAND} in the vm"
+ else
+ command="$@"
+ fi
+
+ local kconfig_file="${OUTPUT_DIR}/latest.config"
+ local make_command="make -j ${NUM_COMPILE_JOBS} KCONFIG_CONFIG=${kconfig_file}"
+
+ # Figure out where the kernel is being built.
+ # O takes precedence over KBUILD_OUTPUT.
+ if [[ "${O:=""}" != "" ]]; then
+ if is_rel_path "${O}"; then
+ O="$(realpath "${PWD}/${O}")"
+ fi
+ kernel_bzimage="${O}/${X86_BZIMAGE}"
+ make_command="${make_command} O=${O}"
+ elif [[ "${KBUILD_OUTPUT:=""}" != "" ]]; then
+ if is_rel_path "${KBUILD_OUTPUT}"; then
+ KBUILD_OUTPUT="$(realpath "${PWD}/${KBUILD_OUTPUT}")"
+ fi
+ kernel_bzimage="${KBUILD_OUTPUT}/${X86_BZIMAGE}"
+ make_command="${make_command} KBUILD_OUTPUT=${KBUILD_OUTPUT}"
+ fi
+
+ populate_url_map
+
+ local rootfs_img="${OUTPUT_DIR}/${ROOTFS_IMAGE}"
+ local mount_dir="${OUTPUT_DIR}/${MOUNT_DIR}"
+
+ echo "Output directory: ${OUTPUT_DIR}"
+
+ mkdir -p "${OUTPUT_DIR}"
+ mkdir -p "${mount_dir}"
+ curl -Lsf "${KCONFIG_URL}" -o "${kconfig_file}"
+
+ if [[ "${kernel_recompile}" == "no" && ! -f "${kernel_bzimage}" ]]; then
+ echo "Kernel image not found in ${kernel_bzimage}, kernel will be recompiled"
+ kernel_recompile="yes"
+ fi
+
+ if [[ "${kernel_recompile}" == "yes" ]]; then
+ recompile_kernel "${kernel_checkout}" "${make_command}"
+ fi
+
+ if [[ "${update_image}" == "no" && ! -f "${rootfs_img}" ]]; then
+ echo "rootfs image not found in ${rootfs_img}"
+ update_image="yes"
+ fi
+
+ if [[ "${update_image}" == "yes" ]]; then
+ create_vm_image
+ fi
+
+ update_selftests "${kernel_checkout}" "${make_command}"
+ update_init_script "${command}" "${log_file}"
+ run_vm "${kernel_bzimage}"
+ copy_logs "${log_file}"
+ echo "Logs saved in ${OUTPUT_DIR}/${log_file}"
+}
+
+catch()
+{
+ local exit_code=$1
+ # This is just a cleanup and the directory may
+ # have already been unmounted. So, don't let this
+ # clobber the error code we intend to return.
+ unmount_image || true
+ exit ${exit_code}
+}
+
+trap 'catch "$?"' EXIT
+
+main "$@"