From 93de2a6a4b91b72607136dd656edf03fb399d27f Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 23 Sep 2026 09:37:21 -0700 Subject: KVM: SEV: Do cache maintenance on the source VM during intra-host migration Manually perform cache maintenance on the source VM during intra-host migration to ensure no stale data is left in CPU caches after the VM is destroyed. Because the source VM is "converted" to a non-SEV VM, KVM's memory reclaim flows won't trigger cache maintenance, e.g. when all guest memory is reclaimed in response to detaching from the mmu_notifier. Note, relying on the destination VM to do cache maintenance isn't an option as KVM doesn't require identical guest memory configurations, i.e. the source VM may have access to memory that the destination VM does not. Enforcing equivalent memory configurations is infeasible, as it would require a *deep* comparison of memslots, e.g. to verify that not only are the memslot identical, but what the memslots point at is also identical. Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration") Cc: stable@vger.kernel.org Reported-by: Stefan Teodorescu Signed-off-by: Sean Christopherson Message-ID: <20260923163721.1584779-3-seanjc@google.com> Signed-off-by: Paolo Bonzini --- tools/verification/tests/engine.sh | 175 +++++++++++++++++++++++++++++++++++++ 1 file changed, 175 insertions(+) create mode 100644 tools/verification/tests/engine.sh (limited to 'tools/verification/tests') diff --git a/tools/verification/tests/engine.sh b/tools/verification/tests/engine.sh new file mode 100644 index 000000000..cfdf2180a --- /dev/null +++ b/tools/verification/tests/engine.sh @@ -0,0 +1,175 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +test_begin() { + # Count tests to allow the test harness to double-check if all were + # included correctly. + ctr=0 + [ -z "$RV" ] && RV="../rv/rv" + [ -z "$RVGEN" ] && RVGEN="python3 ../rvgen" + [ -z "$GOLDEN_DIR" ] && GOLDEN_DIR="tests/golden" + [ -n "$TEST_COUNT" ] && echo "1..$TEST_COUNT" +} + +failure() { + fail=1 + if [ $# -gt 0 ]; then + failbuf+="$1" + failbuf+=$'\n' + fi +} + +report() { + local desc="$1" + + if [ "$fail" -eq 0 ]; then + echo "ok $ctr - $desc" + else + # Add output and exit code as comments in case of failure + echo "not ok $ctr - $desc" + echo -n "$failbuf" + echo "$result" | col -b | while read -r line; do echo "# $line"; done + printf "#\n# exit code %s\n" "$exitcode" + fi +} + +_check() { + local command=$2 + local expected_exitcode=${3:-0} + local expected_output=$4 + local unexpected_output=$5 + local all_lines_pattern=$6 + local patterns="$expected_output $unexpected_output $all_lines_pattern" + local bgpid pid + + eval "$TIMEOUT" "$command" &> check_output.$$ & + bgpid=$! + + if grep -q "\$pid" <<< "$patterns"; then + for _ in {1..30}; do + pid=$(pgrep -f "${command%%[|;&>]*}" | tail -n1) + [ -n "$pid" ] && break + sleep 0.1 + done + fi + + wait $bgpid + exitcode=$? + result=$(tr -d '\0' < check_output.$$) + rm -f check_output.$$ + + failbuf='' + fail=0 + + # Suppress any other error if a needed pid is empty + if [ -z "$pid" ] && grep -q "\$pid" <<< "$patterns"; then + result='' + failure "# Empty pid for $command" + return 1 + fi + + expected_output="${expected_output//\$pid/$pid}" + unexpected_output="${unexpected_output//\$pid/$pid}" + all_lines_pattern="${all_lines_pattern//\$pid/$pid}" + + # Test if the results matches if requested + if [ -n "$expected_output" ] && ! grep -qe "$expected_output" <<< "$result"; then + failure "# Output match failed: \"$expected_output\"" + fi + + if [ -n "$unexpected_output" ] && grep -qe "$unexpected_output" <<< "$result"; then + failure "# Output non-match failed: \"$unexpected_output\"" + fi + + if [ -n "$all_lines_pattern" ] && grep -vqe "$all_lines_pattern" <<< "$result"; then + failure "# All-lines pattern failed: \"$all_lines_pattern\"" + fi + + if [ $exitcode -ne "$expected_exitcode" ]; then + failure "# Expected exit code $expected_exitcode" + fi +} + +check() { + # Simple check: run the command with given arguments and test exit code. + # If TEST_COUNT is set, run the test. Otherwise, just count. + ctr=$((ctr + 1)) + if [ -n "$TEST_COUNT" ]; then + _check "$@" + report "$1" + fi +} + +check_if_exists() { + # Conditional check that skips if a file or folder doesn't exist + local desc=$1 + local command=$2 + local file=$3 + local expected_output=$4 + local unexpected_output=$5 + local all_lines_pattern=$6 + + ctr=$((ctr + 1)) + if [ -n "$TEST_COUNT" ]; then + if [ ! -e "$file" ]; then + echo "ok $ctr - $desc # SKIP file not found: $file" + else + _check "$desc" "$command" 0 "$expected_output" \ + "$unexpected_output" "$all_lines_pattern" + report "$desc" + fi + fi +} + +check_and_compare_folder() { + # Run command, compare generated folder to golden, and cleanup + local desc=$1 + local command=$2 + local generated_dir=$3 + local expected_output=$4 + local unexpected_output=$5 + local golden_dir="$GOLDEN_DIR/$generated_dir" + + ctr=$((ctr + 1)) + if [ -n "$TEST_COUNT" ]; then + rm -rf "$generated_dir" + _check "$desc" "$command" 0 "$expected_output" "$unexpected_output" + + if [ "$fail" -eq 0 ] && [ ! -d "$generated_dir" ]; then + failure "# Generated directory not found: $generated_dir" + fi + + if [ "$fail" -ne 0 ]; then + : + elif ! diff -r "$generated_dir" "$golden_dir" &> /dev/null; then + failure "# Directories differ:" + failbuf+=$(diff -r "$generated_dir" "$golden_dir" 2>&1 | sed 's/^/# /') + failbuf+=$'\n' + fi + + report "$1" + + rm -rf "$generated_dir" + fi +} + +set_timeout() { + TIMEOUT="timeout -v -k 30s $1" +} + +set_expected_timeout() { + TIMEOUT="timeout --preserve-status -k 30s $1" +} + +unset_timeout() { + unset TIMEOUT +} + +test_end() { + # If running without TEST_COUNT, tests are not actually run, just + # counted. In that case, re-run the test with the correct count. + [ -z "$TEST_COUNT" ] && TEST_COUNT=$ctr exec bash "$0" || true +} + +# Avoid any environmental discrepancies +export LC_ALL=C +unset_timeout -- cgit v1.3.1