perf test kvm: Add some basic perf kvm test coverage

#!/bin/bash

# perf kvm tests

# SPDX-License-Identifier: GPL-2.0

set -e

err=0

perfdata=$(mktemp /tmp/__perf_kvm_test.perf.data.XXXXX)

qemu_pid_file=$(mktemp /tmp/__perf_kvm_test.qemu.pid.XXXXX)

cleanup() {

	rm -f "${perfdata}"

	if [ -f "${qemu_pid_file}" ]; then

		if [ -s "${qemu_pid_file}" ]; then

			qemu_pid=$(cat "${qemu_pid_file}")

			if [ -n "${qemu_pid}" ]; then

				kill "${qemu_pid}" 2>/dev/null || true

			fi

		fi

		rm -f "${qemu_pid_file}"

	fi

	trap - EXIT TERM INT

}

trap_cleanup() {

	echo "Unexpected signal in ${FUNCNAME[1]}"

	cleanup

	exit 1

}

trap trap_cleanup EXIT TERM INT

skip() {

	echo "Skip: $1"

	cleanup

	exit 2

}

test_kvm_stat() {

	echo "Testing perf kvm stat"

	echo "Recording kvm events for pid ${qemu_pid}..."

	if ! perf kvm stat record -p "${qemu_pid}" -o "${perfdata}" sleep 1; then

		echo "Failed to record kvm events"

		err=1

		return

	fi

	echo "Reporting kvm events..."

	if ! perf kvm -i "${perfdata}" stat report 2>&1 | grep -q "VM-EXIT"; then

		echo "Failed to find VM-EXIT in report"

		perf kvm -i "${perfdata}" stat report 2>&1

		err=1

		return

	fi

	echo "perf kvm stat test [Success]"

}

test_kvm_record_report() {

	echo "Testing perf kvm record/report"

	echo "Recording kvm profile for pid ${qemu_pid}..."

	# Use --host to avoid needing guest symbols/mounts for this simple test

	# We just want to verify the command runs and produces data

	# We run in background and kill it because 'perf kvm record' appends options

	# after the command, which breaks 'sleep' (e.g. it gets '-e cycles').

	perf kvm --host record -p "${qemu_pid}" -o "${perfdata}" &

	rec_pid=$!

	sleep 1

	kill -INT "${rec_pid}"

	wait "${rec_pid}" || true

	echo "Reporting kvm profile..."

	# Check for some standard output from report

	if ! perf kvm -i "${perfdata}" report --stdio 2>&1 | grep -q "Event count"; then

		echo "Failed to report kvm profile"

		perf kvm -i "${perfdata}" report --stdio 2>&1

		err=1

		return

	fi

	echo "perf kvm record/report test [Success]"

}

test_kvm_buildid_list() {

	echo "Testing perf kvm buildid-list"

	# We reuse the perf.data from the previous record test

	if ! perf kvm --host -i "${perfdata}" buildid-list 2>&1 | grep -q "."; then

		echo "Failed to list buildids"

		perf kvm --host -i "${perfdata}" buildid-list 2>&1

		err=1

		return

	fi

	echo "perf kvm buildid-list test [Success]"

}

setup_qemu() {

	# Find qemu

	if [ "$(uname -m)" = "x86_64" ]; then

		qemu="qemu-system-x86_64"

	elif [ "$(uname -m)" = "aarch64" ]; then

		qemu="qemu-system-aarch64"

	elif [ "$(uname -m)" = "s390x" ]; then

		qemu="qemu-system-s390x"

	elif [ "$(uname -m)" = "ppc64le" ]; then

		qemu="qemu-system-ppc64"

	else

		qemu="qemu-system-$(uname -m)"

	fi

	if ! which -s "$qemu"; then

		skip "$qemu not found"

	fi

	if [ ! -r /dev/kvm ] || [ ! -w /dev/kvm ]; then

		skip "/dev/kvm not accessible"

	fi

	if ! perf kvm stat record -a sleep 0.01 >/dev/null 2>&1; then

		skip "No permission to record kvm events"

	fi

	echo "Starting $qemu..."

	# Start qemu in background, detached, with pidfile

	# We use -display none -daemonize and a monitor to keep it alive/controllable if needed

	# We don't need a real kernel, just KVM active.

	if ! $qemu -enable-kvm -display none -daemonize -pidfile "${qemu_pid_file}" -monitor none; then

		echo "Failed to start qemu"

		err=1

		return

	fi

	# Wait a bit for qemu to start

	sleep 1

	qemu_pid=$(cat "${qemu_pid_file}")

	if ! kill -0 "${qemu_pid}" 2>/dev/null; then

		echo "Qemu process failed to stay alive"

		err=1

		return

	fi

}

setup_qemu

if [ $err -eq 0 ]; then

	test_kvm_stat

	test_kvm_record_report

	test_kvm_buildid_list

fi

cleanup

exit $err