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/rbtree/Makefile | 33 ++++++++++++++++++ tools/testing/rbtree/interval_tree_test.c | 58 +++++++++++++++++++++++++++++++ tools/testing/rbtree/rbtree_test.c | 48 +++++++++++++++++++++++++ tools/testing/rbtree/test.h | 4 +++ 4 files changed, 143 insertions(+) create mode 100644 tools/testing/rbtree/Makefile create mode 100644 tools/testing/rbtree/interval_tree_test.c create mode 100644 tools/testing/rbtree/rbtree_test.c create mode 100644 tools/testing/rbtree/test.h (limited to 'tools/testing/rbtree') diff --git a/tools/testing/rbtree/Makefile b/tools/testing/rbtree/Makefile new file mode 100644 index 000000000..d7bbae2af --- /dev/null +++ b/tools/testing/rbtree/Makefile @@ -0,0 +1,33 @@ +# SPDX-License-Identifier: GPL-2.0 + +.PHONY: clean + +TARGETS = rbtree_test interval_tree_test +OFILES = $(SHARED_OFILES) rbtree-shim.o interval_tree-shim.o maple-shim.o +DEPS = ../../../include/linux/rbtree.h \ + ../../../include/linux/rbtree_types.h \ + ../../../include/linux/rbtree_augmented.h \ + ../../../include/linux/interval_tree.h \ + ../../../include/linux/interval_tree_generic.h \ + ../../../lib/rbtree.c \ + ../../../lib/interval_tree.c + +targets: $(TARGETS) + +include ../shared/shared.mk + +ifeq ($(DEBUG), 1) + CFLAGS += -g +endif + +$(TARGETS): $(OFILES) + +rbtree-shim.o: $(DEPS) +rbtree_test.o: ../../../lib/rbtree_test.c +interval_tree-shim.o: $(DEPS) +interval_tree-shim.o: CFLAGS += -DCONFIG_INTERVAL_TREE_SPAN_ITER +interval_tree_test.o: ../../../lib/interval_tree_test.c +interval_tree_test.o: CFLAGS += -DCONFIG_INTERVAL_TREE_SPAN_ITER + +clean: + $(RM) $(TARGETS) *.o radix-tree.c idr.c generated/* diff --git a/tools/testing/rbtree/interval_tree_test.c b/tools/testing/rbtree/interval_tree_test.c new file mode 100644 index 000000000..49bc5b534 --- /dev/null +++ b/tools/testing/rbtree/interval_tree_test.c @@ -0,0 +1,58 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * interval_tree.c: Userspace Interval Tree test-suite + * Copyright (c) 2025 Wei Yang + */ +#include +#include +#include "shared.h" +#include "maple-shared.h" + +#include "../../../lib/interval_tree_test.c" + +int usage(void) +{ + fprintf(stderr, "Userland interval tree test cases\n"); + fprintf(stderr, " -n: Number of nodes in the interval tree\n"); + fprintf(stderr, " -p: Number of iterations modifying the tree\n"); + fprintf(stderr, " -q: Number of searches to the interval tree\n"); + fprintf(stderr, " -s: Number of iterations searching the tree\n"); + fprintf(stderr, " -a: Searches will iterate all nodes in the tree\n"); + fprintf(stderr, " -m: Largest value for the interval's endpoint\n"); + fprintf(stderr, " -r: Random seed\n"); + exit(-1); +} + +void interval_tree_tests(void) +{ + interval_tree_test_init(); + interval_tree_test_exit(); +} + +int main(int argc, char **argv) +{ + int opt; + + while ((opt = getopt(argc, argv, "n:p:q:s:am:r:")) != -1) { + if (opt == 'n') + nnodes = strtoul(optarg, NULL, 0); + else if (opt == 'p') + perf_loops = strtoul(optarg, NULL, 0); + else if (opt == 'q') + nsearches = strtoul(optarg, NULL, 0); + else if (opt == 's') + search_loops = strtoul(optarg, NULL, 0); + else if (opt == 'a') + search_all = true; + else if (opt == 'm') + max_endpoint = strtoul(optarg, NULL, 0); + else if (opt == 'r') + seed = strtoul(optarg, NULL, 0); + else + usage(); + } + + maple_tree_init(); + interval_tree_tests(); + return 0; +} diff --git a/tools/testing/rbtree/rbtree_test.c b/tools/testing/rbtree/rbtree_test.c new file mode 100644 index 000000000..585c970f6 --- /dev/null +++ b/tools/testing/rbtree/rbtree_test.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * rbtree_test.c: Userspace Red Black Tree test-suite + * Copyright (c) 2025 Wei Yang + */ +#include +#include +#include +#include "shared.h" + +#include "../../../lib/rbtree_test.c" + +int usage(void) +{ + fprintf(stderr, "Userland rbtree test cases\n"); + fprintf(stderr, " -n: Number of nodes in the rb-tree\n"); + fprintf(stderr, " -p: Number of iterations modifying the rb-tree\n"); + fprintf(stderr, " -c: Number of iterations modifying and verifying the rb-tree\n"); + fprintf(stderr, " -r: Random seed\n"); + exit(-1); +} + +void rbtree_tests(void) +{ + rbtree_test_init(); + rbtree_test_exit(); +} + +int main(int argc, char **argv) +{ + int opt; + + while ((opt = getopt(argc, argv, "n:p:c:r:")) != -1) { + if (opt == 'n') + nnodes = strtoul(optarg, NULL, 0); + else if (opt == 'p') + perf_loops = strtoul(optarg, NULL, 0); + else if (opt == 'c') + check_loops = strtoul(optarg, NULL, 0); + else if (opt == 'r') + seed = strtoul(optarg, NULL, 0); + else + usage(); + } + + rbtree_tests(); + return 0; +} diff --git a/tools/testing/rbtree/test.h b/tools/testing/rbtree/test.h new file mode 100644 index 000000000..f1f1b545b --- /dev/null +++ b/tools/testing/rbtree/test.h @@ -0,0 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +void rbtree_tests(void); +void interval_tree_tests(void); -- cgit v1.3.1