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, modeled after the existing selftests vmtest runners (notably tools/testing/selftests/hid/vmtest.sh), to provide a repeatable VM workflow for dmem tests. 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 and reuses the same verbosity and 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/vmtest-dmem.sh | 189 ++++++++++++++++++++++++++ 1 file changed, 189 insertions(+) diff --git a/tools/testing/selftests/cgroup/vmtest-dmem.sh b/tools/testing/selftests/cgroup/vmtest-dmem.sh new file mode 100755 index 0000000000000..e481d3b2cdf8f --- /dev/null +++ b/tools/testing/selftests/cgroup/vmtest-dmem.sh @@ -0,0 +1,189 @@ +#!/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 +# * busybox-static (used by 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 + +readonly SSH_GUEST_PORT="${SSH_GUEST_PORT:-22}" +readonly WAIT_PERIOD=3 +readonly WAIT_PERIOD_MAX=80 +readonly WAIT_TOTAL=$((WAIT_PERIOD * WAIT_PERIOD_MAX)) +readonly QEMU_PIDFILE="$(mktemp /tmp/qemu_dmem_vmtest_XXXX.pid)" +readonly QEMU_OPTS=" --pidfile ${QEMU_PIDFILE} " + +QEMU="qemu-system-$(uname -m)" +VERBOSE=0 +SHELL_MODE=0 +GUEST_TREE="${GUEST_TREE:-$KERNEL_CHECKOUT}" + +usage() { + echo + echo "$0 [OPTIONS]" + echo " -q <qemu> QEMU binary/path (default: ${QEMU})" + echo " -s Start interactive shell in VM" + echo " -v Verbose output (use -vv for vng boot logs)" + echo +} + +die() { + echo "$*" >&2 + exit "${KSFT_FAIL}" +} + +cleanup() { + if [[ -s "${QEMU_PIDFILE}" ]]; then + pkill -SIGTERM -F "${QEMU_PIDFILE}" >/dev/null 2>&1 || true + fi + rm -f "${QEMU_PIDFILE}" +} + +vm_ssh() { + stdbuf -oL ssh -q \ + -F "${HOME}/.cache/virtme-ng/.ssh/virtme-ng-ssh.conf" \ + -l root "virtme-ng%${SSH_GUEST_PORT}" \ + "$@" +} + +check_deps() { + for dep in vng "${QEMU}" busybox pkill ssh; do + if ! command -v "${dep}" >/dev/null 2>&1; then + echo "skip: dependency ${dep} not found" + exit "${KSFT_SKIP}" + fi + done +} + +vm_start() { + local logfile=/dev/null + local verbose_opt="" + + if [[ "${VERBOSE}" -eq 2 ]]; then + verbose_opt="--verbose" + logfile=/dev/stdout + fi + + vng \ + --run \ + ${verbose_opt} \ + --qemu-opts="${QEMU_OPTS}" \ + --qemu="$(command -v "${QEMU}")" \ + --user root \ + --ssh "${SSH_GUEST_PORT}" \ + --rw &>"${logfile}" & + + local vng_pid=$! + local elapsed=0 + + while [[ ! -s "${QEMU_PIDFILE}" ]]; do + kill -0 "${vng_pid}" 2>/dev/null || die "vng exited early; failed to boot VM" + [[ "${elapsed}" -ge "${WAIT_TOTAL}" ]] && die "timed out waiting for VM boot" + sleep 1 + elapsed=$((elapsed + 1)) + done +} + +vm_wait_for_ssh() { + local i=0 + while true; do + vm_ssh -- true && break + i=$((i + 1)) + [[ "${i}" -gt "${WAIT_PERIOD_MAX}" ]] && die "timed out waiting for guest ssh" + sleep "${WAIT_PERIOD}" + done +} + +check_guest_requirements() { + local cfg_ok + cfg_ok="$(vm_ssh -- "cfg=/boot/config-\$(uname -r); \ + if [[ -r \"\$cfg\" ]]; then grep -Eq '^CONFIG_CGROUP_DMEM=(y|m)$' \"\$cfg\"; \ + elif [[ -r /proc/config.gz ]]; then \ + zgrep -Eq '^CONFIG_CGROUP_DMEM=(y|m)$' /proc/config.gz; \ + else false; fi; echo \$?")" + [[ "${cfg_ok}" == "0" ]] || die "guest kernel missing CONFIG_CGROUP_DMEM" +} + +setup_guest_dmem_helper() { + local kdir + + vm_ssh -- "mountpoint -q /sys/kernel/debug || \ + mount -t debugfs none /sys/kernel/debug" || true + + # Already available (built-in or loaded). + if vm_ssh -- "[[ -e /sys/kernel/debug/dmem_selftest/charge ]]"; then + echo "dmem_selftest ready" + return 0 + fi + + # Fast path: try installed module. + vm_ssh -- "modprobe -q dmem_selftest 2>/dev/null || true" + if vm_ssh -- "[[ -e /sys/kernel/debug/dmem_selftest/charge ]]"; then + echo "dmem_selftest ready" + return 0 + fi + + # Fallback: build only this module against running guest kernel, + # then insert it. + kdir="$(vm_ssh -- "echo /lib/modules/\$(uname -r)/build")" + if vm_ssh -- "[[ -d '${kdir}' ]]"; then + echo "Building dmem_selftest.ko against running guest kernel..." + vm_ssh -- "make -C '${kdir}' \ + M='${GUEST_TREE}/kernel/cgroup' \ + CONFIG_DMEM_SELFTEST=m modules" + vm_ssh -- "insmod '${GUEST_TREE}/kernel/cgroup/dmem_selftest.ko' \ + 2>/dev/null || modprobe -q dmem_selftest 2>/dev/null || true" + fi + + if vm_ssh -- "[[ -e /sys/kernel/debug/dmem_selftest/charge ]]"; then + echo "dmem_selftest ready" + return 0 + fi + + die "dmem_selftest unavailable (modprobe/build+insmod failed)" +} + +run_test() { + vm_ssh -- "cd '${GUEST_TREE}' && make -C tools/testing/selftests TARGETS=cgroup" + vm_ssh -- "cd '${GUEST_TREE}' && ./tools/testing/selftests/cgroup/test_dmem" +} + +while getopts ":hvq:s" o; do + case "${o}" in + v) VERBOSE=$((VERBOSE + 1)) ;; + q) QEMU="${OPTARG}" ;; + s) SHELL_MODE=1 ;; + h|*) usage ;; + esac +done + +trap cleanup EXIT + +check_deps +echo "Booting virtme-ng VM..." +vm_start +vm_wait_for_ssh +echo "VM is reachable via SSH." +check_guest_requirements +setup_guest_dmem_helper + +if [[ "${SHELL_MODE}" -eq 1 ]]; then + echo "Starting interactive shell in VM. Exit to stop VM." + vm_ssh -t -- "cd '${GUEST_TREE}' && exec bash --noprofile --norc" + exit "${KSFT_PASS}" +fi + +echo "Running cgroup/test_dmem in VM..." +run_test +echo "PASS: test_dmem completed" +exit "${KSFT_PASS}" -- 2.52.0
