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 --- scripts/rust_is_available.sh | 259 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 259 insertions(+) create mode 100755 scripts/rust_is_available.sh (limited to 'scripts/rust_is_available.sh') diff --git a/scripts/rust_is_available.sh b/scripts/rust_is_available.sh new file mode 100755 index 000000000..c30983562 --- /dev/null +++ b/scripts/rust_is_available.sh @@ -0,0 +1,259 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# +# Tests whether a suitable Rust toolchain is available. + +set -e + +min_tool_version=$(dirname $0)/min-tool-version.sh + +# Convert the version string x.y.z to a canonical up-to-7-digits form. +# +# Note that this function uses one more digit (compared to other +# instances in other version scripts) to give a bit more space to +# `rustc` since it will reach 1.100.0 in late 2026. +get_canonical_version() +{ + IFS=. + set -- $1 + echo $((100000 * $1 + 100 * $2 + $3)) +} + +# Print a reference to the Quick Start guide in the documentation. +print_docs_reference() +{ + echo >&2 "***" + echo >&2 "*** Please see Documentation/rust/quick-start.rst for details" + echo >&2 "*** on how to set up the Rust support." + echo >&2 "***" +} + +# Print an explanation about the fact that the script is meant to be called from Kbuild. +print_kbuild_explanation() +{ + echo >&2 "***" + echo >&2 "*** This script is intended to be called from Kbuild." + echo >&2 "*** Please use the 'rustavailable' target to call it instead." + echo >&2 "*** Otherwise, the results may not be meaningful." + exit 1 +} + +# If the script fails for any reason, or if there was any warning, then +# print a reference to the documentation on exit. +warning=0 +trap 'if [ $? -ne 0 ] || [ $warning -ne 0 ]; then print_docs_reference; fi' EXIT + +# Check that the expected environment variables are set. +if [ -z "${RUSTC+x}" ]; then + echo >&2 "***" + echo >&2 "*** Environment variable 'RUSTC' is not set." + print_kbuild_explanation +fi + +if [ -z "${BINDGEN+x}" ]; then + echo >&2 "***" + echo >&2 "*** Environment variable 'BINDGEN' is not set." + print_kbuild_explanation +fi + +if [ -z "${CC+x}" ]; then + echo >&2 "***" + echo >&2 "*** Environment variable 'CC' is not set." + print_kbuild_explanation +fi + +# Check that the Rust compiler exists. +if ! command -v "$RUSTC" >/dev/null; then + echo >&2 "***" + echo >&2 "*** Rust compiler '$RUSTC' could not be found." + echo >&2 "***" + exit 1 +fi + +# Check that the Rust bindings generator exists. +if ! command -v "$BINDGEN" >/dev/null; then + echo >&2 "***" + echo >&2 "*** Rust bindings generator '$BINDGEN' could not be found." + echo >&2 "***" + exit 1 +fi + +# Check that the Rust compiler version is suitable. +# +# Non-stable and distributions' versions may have a version suffix, e.g. `-dev`. +rust_compiler_output=$( \ + LC_ALL=C "$RUSTC" --version 2>/dev/null +) || rust_compiler_code=$? +if [ -n "$rust_compiler_code" ]; then + echo >&2 "***" + echo >&2 "*** Running '$RUSTC' to check the Rust compiler version failed with" + echo >&2 "*** code $rust_compiler_code. See output and docs below for details:" + echo >&2 "***" + echo >&2 "$rust_compiler_output" + echo >&2 "***" + exit 1 +fi +rust_compiler_version=$( \ + echo "$rust_compiler_output" \ + | sed -nE '1s:.*rustc ([0-9]+\.[0-9]+\.[0-9]+).*:\1:p' +) +if [ -z "$rust_compiler_version" ]; then + echo >&2 "***" + echo >&2 "*** Running '$RUSTC' to check the Rust compiler version did not return" + echo >&2 "*** an expected output. See output and docs below for details:" + echo >&2 "***" + echo >&2 "$rust_compiler_output" + echo >&2 "***" + exit 1 +fi +rust_compiler_min_version=$($min_tool_version rustc) +rust_compiler_cversion=$(get_canonical_version $rust_compiler_version) +rust_compiler_min_cversion=$(get_canonical_version $rust_compiler_min_version) +if [ "$rust_compiler_cversion" -lt "$rust_compiler_min_cversion" ]; then + echo >&2 "***" + echo >&2 "*** Rust compiler '$RUSTC' is too old." + echo >&2 "*** Your version: $rust_compiler_version" + echo >&2 "*** Minimum version: $rust_compiler_min_version" + echo >&2 "***" + exit 1 +fi + +# Check that the Rust bindings generator is suitable. +# +# Non-stable and distributions' versions may have a version suffix, e.g. `-dev`. +rust_bindings_generator_output=$( \ + LC_ALL=C "$BINDGEN" --version 2>/dev/null +) || rust_bindings_generator_code=$? +if [ -n "$rust_bindings_generator_code" ]; then + echo >&2 "***" + echo >&2 "*** Running '$BINDGEN' to check the Rust bindings generator version failed with" + echo >&2 "*** code $rust_bindings_generator_code. See output and docs below for details:" + echo >&2 "***" + echo >&2 "$rust_bindings_generator_output" + echo >&2 "***" + exit 1 +fi +rust_bindings_generator_version=$( \ + echo "$rust_bindings_generator_output" \ + | sed -nE '1s:.*bindgen ([0-9]+\.[0-9]+\.[0-9]+).*:\1:p' +) +if [ -z "$rust_bindings_generator_version" ]; then + echo >&2 "***" + echo >&2 "*** Running '$BINDGEN' to check the bindings generator version did not return" + echo >&2 "*** an expected output. See output and docs below for details:" + echo >&2 "***" + echo >&2 "$rust_bindings_generator_output" + echo >&2 "***" + exit 1 +fi +rust_bindings_generator_min_version=$($min_tool_version bindgen) +rust_bindings_generator_cversion=$(get_canonical_version $rust_bindings_generator_version) +rust_bindings_generator_min_cversion=$(get_canonical_version $rust_bindings_generator_min_version) +if [ "$rust_bindings_generator_cversion" -lt "$rust_bindings_generator_min_cversion" ]; then + echo >&2 "***" + echo >&2 "*** Rust bindings generator '$BINDGEN' is too old." + echo >&2 "*** Your version: $rust_bindings_generator_version" + echo >&2 "*** Minimum version: $rust_bindings_generator_min_version" + echo >&2 "***" + exit 1 +fi + +# Check that the `libclang` used by the Rust bindings generator is suitable. +# +# In order to do that, first invoke `bindgen` to get the `libclang` version +# found by `bindgen`. This step may already fail if, for instance, `libclang` +# is not found, thus inform the user in such a case. +bindgen_libclang_output=$( \ + LC_ALL=C "$BINDGEN" $(dirname $0)/rust_is_available_bindgen_libclang.h 2>&1 >/dev/null +) || bindgen_libclang_code=$? +if [ -n "$bindgen_libclang_code" ]; then + echo >&2 "***" + echo >&2 "*** Running '$BINDGEN' to check the libclang version (used by the Rust" + echo >&2 "*** bindings generator) failed with code $bindgen_libclang_code. This may be caused by" + echo >&2 "*** a failure to locate libclang. See output and docs below for details:" + echo >&2 "***" + echo >&2 "$bindgen_libclang_output" + echo >&2 "***" + exit 1 +fi + +# `bindgen` returned successfully, thus use the output to check that the version +# of the `libclang` found by the Rust bindings generator is suitable. +# +# Unlike other version checks, note that this one does not necessarily appear +# in the first line of the output, thus no `sed` address is provided. +bindgen_libclang_version=$( \ + echo "$bindgen_libclang_output" \ + | sed -nE 's:.*clang version ([0-9]+\.[0-9]+\.[0-9]+).*:\1:p' +) +if [ -z "$bindgen_libclang_version" ]; then + echo >&2 "***" + echo >&2 "*** Running '$BINDGEN' to check the libclang version (used by the Rust" + echo >&2 "*** bindings generator) did not return an expected output. See output" + echo >&2 "*** and docs below for details:" + echo >&2 "***" + echo >&2 "$bindgen_libclang_output" + echo >&2 "***" + exit 1 +fi +bindgen_libclang_min_version=$($min_tool_version llvm) +bindgen_libclang_cversion=$(get_canonical_version $bindgen_libclang_version) +bindgen_libclang_min_cversion=$(get_canonical_version $bindgen_libclang_min_version) +if [ "$bindgen_libclang_cversion" -lt "$bindgen_libclang_min_cversion" ]; then + echo >&2 "***" + echo >&2 "*** libclang (used by the Rust bindings generator '$BINDGEN') is too old." + echo >&2 "*** Your version: $bindgen_libclang_version" + echo >&2 "*** Minimum version: $bindgen_libclang_min_version" + echo >&2 "***" + exit 1 +fi + +if [ "$bindgen_libclang_cversion" -ge 2200000 ] && + [ "$rust_bindings_generator_cversion" -lt 7201 ]; then + # Distributions may have patched the issue. + if ! "$BINDGEN" $(dirname $0)/rust_is_available_bindgen_libclang_22.h | grep -q 'pub foo'; then + echo >&2 "***" + echo >&2 "*** Rust bindings generator '$BINDGEN' < 0.72.1 together with libclang >= 22" + echo >&2 "*** may not work due to a bug (https://github.com/rust-lang/rust-bindgen/pull/3278)." + echo >&2 "*** Your bindgen version: $rust_bindings_generator_version" + echo >&2 "*** Your libclang version: $bindgen_libclang_version" + echo >&2 "***" + warning=1 + fi +fi + +# If the C compiler is Clang, then we can also check whether its version +# matches the `libclang` version used by the Rust bindings generator. +# +# In the future, we might be able to perform a full version check, see +# https://github.com/rust-lang/rust-bindgen/issues/2138. +cc_name=$($(dirname $0)/cc-version.sh $CC | cut -f1 -d' ') +if [ "$cc_name" = Clang ]; then + clang_version=$( \ + LC_ALL=C $CC --version 2>/dev/null \ + | sed -nE '1s:.*version ([0-9]+\.[0-9]+\.[0-9]+).*:\1:p' + ) + if [ "$clang_version" != "$bindgen_libclang_version" ]; then + echo >&2 "***" + echo >&2 "*** libclang (used by the Rust bindings generator '$BINDGEN')" + echo >&2 "*** version does not match Clang's. This may be a problem." + echo >&2 "*** libclang version: $bindgen_libclang_version" + echo >&2 "*** Clang version: $clang_version" + echo >&2 "***" + warning=1 + fi +fi + +# Check that the source code for the `core` standard library exists. +# +# `$KRUSTFLAGS` is passed in case the user added `--sysroot`. +rustc_sysroot=$("$RUSTC" $KRUSTFLAGS --print sysroot) +rustc_src=${RUST_LIB_SRC:-"$rustc_sysroot/lib/rustlib/src/rust/library"} +rustc_src_core="$rustc_src/core/src/lib.rs" +if [ ! -e "$rustc_src_core" ]; then + echo >&2 "***" + echo >&2 "*** Source code for the 'core' standard library could not be found" + echo >&2 "*** at '$rustc_src_core'." + echo >&2 "***" + exit 1 +fi -- cgit v1.3.1