Currently, test_dmem relies on the dmem_selftest helper module and a VM setup that may not have the helper preinstalled. This makes automated coverage of dmem charge paths harder in virtme-based runs.
Add tools/testing/selftests/cgroup/vmtest-dmem.sh to provide a repeatable VM workflow for dmem tests. The script uses vng --exec to run the test directly inside a virtme-ng guest with minimal setup. The script boots a virtme-ng guest, validates dmem controller availability, ensures the dmem helper path is present, and runs tools/testing/selftests/cgroup/test_dmem. If the helper is not available as a loaded module, it attempts module build/load for the running guest kernel before executing the test binary. The runner also supports interactive shell mode (-s) and reuses the verbosity and KTAP exit-code conventions used by other vmtest scripts, so it integrates with existing kselftest workflows. Signed-off-by: Albert Esteve <[email protected]> --- tools/testing/selftests/cgroup/Makefile | 2 +- tools/testing/selftests/cgroup/vmtest-dmem.sh | 156 ++++++++++++++++++++++++++ 2 files changed, 157 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/cgroup/Makefile b/tools/testing/selftests/cgroup/Makefile index e1a5e9316620e..2c407710c6e3b 100644 --- a/tools/testing/selftests/cgroup/Makefile +++ b/tools/testing/selftests/cgroup/Makefile @@ -3,7 +3,7 @@ CFLAGS += -Wall -pthread all: ${HELPER_PROGS} -TEST_FILES := with_stress.sh +TEST_FILES := with_stress.sh vmtest-dmem.sh TEST_PROGS := test_stress.sh test_cpuset_prs.sh test_cpuset_v1_hp.sh TEST_GEN_FILES := wait_inotify # Keep the lists lexicographically sorted diff --git a/tools/testing/selftests/cgroup/vmtest-dmem.sh b/tools/testing/selftests/cgroup/vmtest-dmem.sh new file mode 100755 index 0000000000000..b395b7153f635 --- /dev/null +++ b/tools/testing/selftests/cgroup/vmtest-dmem.sh @@ -0,0 +1,156 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Copyright (c) 2026 Red Hat, Inc. +# +# Run cgroup test_dmem inside a virtme-ng VM. +# Dependencies: +# * virtme-ng +# * qemu (used by virtme-ng) + +set -euo pipefail + +readonly SCRIPT_DIR="$(cd -P -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd -P)" +readonly KERNEL_CHECKOUT="$(realpath "${SCRIPT_DIR}"/../../../../)" + +source "${SCRIPT_DIR}"/../kselftest/ktap_helpers.sh + +QEMU="qemu-system-$(uname -m)" +VERBOSE=0 +SHELL_MODE=0 +GUEST_TREE="${GUEST_TREE:-$KERNEL_CHECKOUT}" + +VM_SCRIPT="" + +function usage() { + cat <<EOF +$0 [OPTIONS] +Options: + -q QEMU binary/path (default: ${QEMU}) + -s Start interactive shell in VM instead of running tests + -v Verbose output (vng boot logs on stdout) + -h Display this help +EOF +} + +function cleanup() { + rm -f "${VM_SCRIPT}" +} +trap cleanup EXIT + +function skip() { + local msg=${1:-""} + + ktap_test_skip "${msg}" + exit "${KSFT_SKIP}" +} + +function fail() { + local msg=${1:-""} + + ktap_test_fail "${msg}" + exit "${KSFT_FAIL}" +} + +function check_deps() { + for dep in vng "${QEMU}"; do + if ! command -v "${dep}" >/dev/null 2>&1; then + skip "dependency ${dep} not found" + fi + done +} + +# Run vng with common flags. Extra arguments are appended by the caller: +# --exec <script> for automated test runs +# (nothing) for interactive shell mode +function run_vm() { + local verbose_opt="" + + [[ "${VERBOSE}" -eq 1 ]] && verbose_opt="--verbose" + + vng \ + --run \ + ${verbose_opt:+"${verbose_opt}"} \ + --qemu="$(command -v "${QEMU}")" \ + --user root \ + --rw \ + "$@" +} + +function main() { + while getopts ':hvq:s' opt; do + case "${opt}" in + v) VERBOSE=1 ;; + q) QEMU="${OPTARG}" ;; + s) SHELL_MODE=1 ;; + h) usage; exit 0 ;; + *) usage; exit 1 ;; + esac + done + + check_deps + + if [[ "${SHELL_MODE}" -eq 1 ]]; then + echo "Starting interactive shell in VM. Exit to stop VM." + run_vm + exit 0 + fi + + ktap_print_header + ktap_set_plan 1 + + # Write the VM-side script to a tempfile. Because vng mounts the host + # filesystem read-write via --rw, the guest can read it at the same path. + VM_SCRIPT="$(mktemp --suffix=.sh /tmp/dmem_vmtest_XXXX)" + + cat > "${VM_SCRIPT}" << EOF +#!/bin/bash +set -euo pipefail + +mountpoint -q /sys/kernel/debug || mount -t debugfs none /sys/kernel/debug + +# Verify cgroup controllers are available. +if ! grep -q dmem /sys/fs/cgroup/cgroup.controllers || \ + ! grep -q memory /sys/fs/cgroup/cgroup.controllers; then + echo "guest kernel missing CONFIG_CGROUP_DMEM or CONFIG_MEMCG" >&2 + exit 1 +fi + +# Load dmem_selftest: try built-in, then modprobe, then build + insmod. +if [[ -e /sys/kernel/debug/dmem_selftest/charge ]]; then + echo "dmem_selftest ready (built-in or already loaded)" +elif modprobe -q dmem_selftest 2>/dev/null && \ + [[ -e /sys/kernel/debug/dmem_selftest/charge ]]; then + echo "dmem_selftest ready (modprobe)" +else + kdir="/lib/modules/\$(uname -r)/build" + if [[ -d "\$kdir" ]]; then + echo "Building dmem_selftest.ko against running guest kernel..." + if make -C "\$kdir" M="${GUEST_TREE}/kernel/cgroup" \ + CONFIG_DMEM_SELFTEST=m modules; then + insmod "${GUEST_TREE}/kernel/cgroup/dmem_selftest.ko" \ + 2>/dev/null || modprobe -q dmem_selftest 2>/dev/null || true + fi + fi + if [[ ! -e /sys/kernel/debug/dmem_selftest/charge ]]; then + echo "dmem_selftest unavailable (modprobe/build+insmod failed)" >&2 + exit 1 + fi + echo "dmem_selftest ready (built + insmod)" +fi + +echo "Running cgroup/test_dmem in VM..." +cd "${GUEST_TREE}" +make -C tools/testing/selftests TARGETS=cgroup +./tools/testing/selftests/cgroup/test_dmem +EOF + + echo "Booting virtme-ng VM..." + if run_vm --exec "bash ${VM_SCRIPT}"; then + ktap_test_pass "test_dmem" + else + fail "test_dmem" + fi +} + +main "$@" -- 2.53.0
