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 --- lib/zstd/common/debug.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 lib/zstd/common/debug.c (limited to 'lib/zstd/common/debug.c') diff --git a/lib/zstd/common/debug.c b/lib/zstd/common/debug.c new file mode 100644 index 000000000..8eb6aa9a3 --- /dev/null +++ b/lib/zstd/common/debug.c @@ -0,0 +1,31 @@ +// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause +/* ****************************************************************** + * debug + * Part of FSE library + * Copyright (c) Meta Platforms, Inc. and affiliates. + * + * You can contact the author at : + * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy + * + * This source code is licensed under both the BSD-style license (found in the + * LICENSE file in the root directory of this source tree) and the GPLv2 (found + * in the COPYING file in the root directory of this source tree). + * You may select, at your option, one of the above-listed licenses. +****************************************************************** */ + + +/* + * This module only hosts one global variable + * which can be used to dynamically influence the verbosity of traces, + * such as DEBUGLOG and RAWLOG + */ + +#include "debug.h" + +#if (DEBUGLEVEL>=2) +/* We only use this when DEBUGLEVEL>=2, but we get -Werror=pedantic errors if a + * translation unit is empty. So remove this from Linux kernel builds, but + * otherwise just leave it in. + */ +int g_debuglevel = DEBUGLEVEL; +#endif -- cgit v1.3.1