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/testing/selftests/dt/.gitignore | 1 + tools/testing/selftests/dt/Makefile | 21 +++++ tools/testing/selftests/dt/compatible_ignore_list | 1 + .../testing/selftests/dt/test_unprobed_devices.sh | 93 ++++++++++++++++++++++ 4 files changed, 116 insertions(+) create mode 100644 tools/testing/selftests/dt/.gitignore create mode 100644 tools/testing/selftests/dt/Makefile create mode 100644 tools/testing/selftests/dt/compatible_ignore_list create mode 100755 tools/testing/selftests/dt/test_unprobed_devices.sh (limited to 'tools/testing/selftests/dt') diff --git a/tools/testing/selftests/dt/.gitignore b/tools/testing/selftests/dt/.gitignore new file mode 100644 index 000000000..f6476c9f2 --- /dev/null +++ b/tools/testing/selftests/dt/.gitignore @@ -0,0 +1 @@ +compatible_list diff --git a/tools/testing/selftests/dt/Makefile b/tools/testing/selftests/dt/Makefile new file mode 100644 index 000000000..2d33ee9e9 --- /dev/null +++ b/tools/testing/selftests/dt/Makefile @@ -0,0 +1,21 @@ +PY3 = $(shell which python3 2>/dev/null) + +ifneq ($(PY3),) + +TEST_PROGS := test_unprobed_devices.sh +TEST_GEN_FILES := compatible_list +TEST_FILES := compatible_ignore_list + +include ../lib.mk + +$(OUTPUT)/compatible_list: + $(top_srcdir)/scripts/dtc/dt-extract-compatibles -d $(top_srcdir) > $@ + +else + +all: no_py3_warning + +no_py3_warning: + @echo "Missing python3. This test will be skipped." + +endif diff --git a/tools/testing/selftests/dt/compatible_ignore_list b/tools/testing/selftests/dt/compatible_ignore_list new file mode 100644 index 000000000..1323903fe --- /dev/null +++ b/tools/testing/selftests/dt/compatible_ignore_list @@ -0,0 +1 @@ +simple-mfd diff --git a/tools/testing/selftests/dt/test_unprobed_devices.sh b/tools/testing/selftests/dt/test_unprobed_devices.sh new file mode 100755 index 000000000..5e3f42ef2 --- /dev/null +++ b/tools/testing/selftests/dt/test_unprobed_devices.sh @@ -0,0 +1,93 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# Copyright (c) 2023 Collabora Ltd +# +# Based on Frank Rowand's dt_stat script. +# +# This script tests for devices that were declared on the Devicetree and are +# expected to bind to a driver, but didn't. +# +# To achieve this, two lists are used: +# * a list of the compatibles that can be matched by a Devicetree node +# * a list of compatibles that should be ignored +# + +DIR="$(dirname $(readlink -f "$0"))" + +source "${DIR}"/../kselftest/ktap_helpers.sh + +PDT=/proc/device-tree/ +COMPAT_LIST="${DIR}"/compatible_list +IGNORE_LIST="${DIR}"/compatible_ignore_list + +ktap_print_header + +if [[ ! -d "${PDT}" ]]; then + ktap_skip_all "${PDT} doesn't exist." + exit "${KSFT_SKIP}" +fi + +nodes_compatible=$( + for node in $(find ${PDT} -type d); do + [ ! -f "${node}"/compatible ] && continue + # Check if node is available + if [[ -e "${node}"/status ]]; then + status=$(tr -d '\000' < "${node}"/status) + if [[ "${status}" != "okay" && "${status}" != "ok" ]]; then + if [ -n "${disabled_nodes_regex}" ]; then + disabled_nodes_regex="${disabled_nodes_regex}|${node}" + else + disabled_nodes_regex="${node}" + fi + continue + fi + fi + + # Ignore this node if one of its ancestors was disabled + if [ -n "${disabled_nodes_regex}" ]; then + echo "${node}" | grep -q -E "${disabled_nodes_regex}" && continue + fi + + echo "${node}" | sed -e 's|\/proc\/device-tree||' + done | sort + ) + +nodes_dev_bound=$( + IFS=$'\n' + for dev_dir in $(find /sys/devices -type d); do + [ ! -f "${dev_dir}"/uevent ] && continue + [ ! -d "${dev_dir}"/driver ] && continue + + grep '^OF_FULLNAME=' "${dev_dir}"/uevent | sed -e 's|OF_FULLNAME=||' + done + ) + +num_tests=$(echo ${nodes_compatible} | wc -w) +ktap_set_plan "${num_tests}" + +retval="${KSFT_PASS}" +for node in ${nodes_compatible}; do + if ! echo "${nodes_dev_bound}" | grep -E -q "(^| )${node}( |\$)"; then + compatibles=$(tr '\000' '\n' < "${PDT}"/"${node}"/compatible) + + for compatible in ${compatibles}; do + if grep -x -q "${compatible}" "${IGNORE_LIST}"; then + continue + fi + + if grep -x -q "${compatible}" "${COMPAT_LIST}"; then + ktap_test_fail "${node}" + retval="${KSFT_FAIL}" + continue 2 + fi + done + ktap_test_skip "${node}" + else + ktap_test_pass "${node}" + fi + +done + +ktap_print_totals +exit "${retval}" -- cgit v1.3.1