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/Makefile.propeller | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) create mode 100644 scripts/Makefile.propeller (limited to 'scripts/Makefile.propeller') diff --git a/scripts/Makefile.propeller b/scripts/Makefile.propeller new file mode 100644 index 000000000..48a660128 --- /dev/null +++ b/scripts/Makefile.propeller @@ -0,0 +1,39 @@ +# SPDX-License-Identifier: GPL-2.0 + +# Enable available and selected Clang Propeller features. +ifdef CLANG_PROPELLER_PROFILE_PREFIX + CFLAGS_PROPELLER_CLANG := -fbasic-block-sections=list=$(CLANG_PROPELLER_PROFILE_PREFIX)_cc_profile.txt -ffunction-sections + KBUILD_LDFLAGS += --symbol-ordering-file=$(CLANG_PROPELLER_PROFILE_PREFIX)_ld_profile.txt --no-warn-symbol-ordering +else + # Starting with Clang v20, the '-fbasic-block-sections=labels' option is + # deprecated. Use the recommended '-fbasic-block-address-map' option. + # Link: https://github.com/llvm/llvm-project/pull/110039 + ifeq ($(call clang-min-version, 200000),y) + CFLAGS_PROPELLER_CLANG := -fbasic-block-address-map + else + CFLAGS_PROPELLER_CLANG := -fbasic-block-sections=labels + endif +endif + +# Propeller requires debug information to embed module names in the profiles. +# If CONFIG_DEBUG_INFO is not enabled, set -gmlt option. Skip this for AutoFDO, +# as the option should already be set. +ifndef CONFIG_DEBUG_INFO + ifndef CONFIG_AUTOFDO_CLANG + CFLAGS_PROPELLER_CLANG += -gmlt + endif +endif + +ifdef CONFIG_LTO_CLANG_THIN + ifdef CLANG_PROPELLER_PROFILE_PREFIX + KBUILD_LDFLAGS += --lto-basic-block-sections=$(CLANG_PROPELLER_PROFILE_PREFIX)_cc_profile.txt + else + ifeq ($(call test-ge, $(CONFIG_LLD_VERSION), 200000),y) + KBUILD_LDFLAGS += --lto-basic-block-address-map + else + KBUILD_LDFLAGS += --lto-basic-block-sections=labels + endif + endif +endif + +export CFLAGS_PROPELLER_CLANG -- cgit v1.3.1