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/tests/test_bits.c | 159 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 159 insertions(+) create mode 100644 lib/tests/test_bits.c (limited to 'lib/tests/test_bits.c') diff --git a/lib/tests/test_bits.c b/lib/tests/test_bits.c new file mode 100644 index 000000000..ab88e50d2 --- /dev/null +++ b/lib/tests/test_bits.c @@ -0,0 +1,159 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Test cases for functions and macros in bits.h + */ + +#include +#include +#include + +#define assert_type(t, x) _Generic(x, t: x, default: 0) + +static_assert(assert_type(u8, BIT_U8(0)) == 1u); +static_assert(assert_type(u16, BIT_U16(0)) == 1u); +static_assert(assert_type(u32, BIT_U32(0)) == 1u); +static_assert(assert_type(u64, BIT_U64(0)) == 1ull); + +static_assert(assert_type(u8, BIT_U8(7)) == 0x80u); +static_assert(assert_type(u16, BIT_U16(15)) == 0x8000u); +static_assert(assert_type(u32, BIT_U32(31)) == 0x80000000u); +static_assert(assert_type(u64, BIT_U64(63)) == 0x8000000000000000ull); + +static_assert(assert_type(unsigned long, GENMASK(31, 0)) == U32_MAX); +static_assert(assert_type(unsigned long long, GENMASK_ULL(63, 0)) == U64_MAX); +static_assert(assert_type(u8, GENMASK_U8(7, 0)) == U8_MAX); +static_assert(assert_type(u16, GENMASK_U16(15, 0)) == U16_MAX); +static_assert(assert_type(u32, GENMASK_U32(31, 0)) == U32_MAX); +static_assert(assert_type(u64, GENMASK_U64(63, 0)) == U64_MAX); + +/* FIXME: add a test case written in asm for GENMASK() and GENMASK_ULL() */ + +static void __genmask_test(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, 1ul, __GENMASK(0, 0)); + KUNIT_EXPECT_EQ(test, 3ul, __GENMASK(1, 0)); + KUNIT_EXPECT_EQ(test, 6ul, __GENMASK(2, 1)); + KUNIT_EXPECT_EQ(test, 0xFFFFFFFFul, __GENMASK(31, 0)); +} + +static void __genmask_ull_test(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, 1ull, __GENMASK_ULL(0, 0)); + KUNIT_EXPECT_EQ(test, 3ull, __GENMASK_ULL(1, 0)); + KUNIT_EXPECT_EQ(test, 0x000000ffffe00000ull, __GENMASK_ULL(39, 21)); + KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, __GENMASK_ULL(63, 0)); +} + +static void genmask_test(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, 1ul, GENMASK(0, 0)); + KUNIT_EXPECT_EQ(test, 3ul, GENMASK(1, 0)); + KUNIT_EXPECT_EQ(test, 6ul, GENMASK(2, 1)); + KUNIT_EXPECT_EQ(test, 0xFFFFFFFFul, GENMASK(31, 0)); + + KUNIT_EXPECT_EQ(test, 1u, GENMASK_U8(0, 0)); + KUNIT_EXPECT_EQ(test, 3u, GENMASK_U16(1, 0)); + KUNIT_EXPECT_EQ(test, 0x10000, GENMASK_U32(16, 16)); + +#ifdef TEST_GENMASK_FAILURES + /* these should fail compilation */ + GENMASK(0, 1); + GENMASK(0, 10); + GENMASK(9, 10); + + GENMASK_U32(0, 31); + GENMASK_U64(64, 0); + GENMASK_U32(32, 0); + GENMASK_U16(16, 0); + GENMASK_U8(8, 0); +#endif + + +} + +static void genmask_ull_test(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, 1ull, GENMASK_ULL(0, 0)); + KUNIT_EXPECT_EQ(test, 3ull, GENMASK_ULL(1, 0)); + KUNIT_EXPECT_EQ(test, 0x000000ffffe00000ull, GENMASK_ULL(39, 21)); + KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, GENMASK_ULL(63, 0)); + +#ifdef TEST_GENMASK_FAILURES + /* these should fail compilation */ + GENMASK_ULL(0, 1); + GENMASK_ULL(0, 10); + GENMASK_ULL(9, 10); +#endif +} + +static void genmask_u128_test(struct kunit *test) +{ +#ifdef CONFIG_ARCH_SUPPORTS_INT128 + /* Below 64 bit masks */ + KUNIT_EXPECT_EQ(test, 0x0000000000000001ull, GENMASK_U128(0, 0)); + KUNIT_EXPECT_EQ(test, 0x0000000000000003ull, GENMASK_U128(1, 0)); + KUNIT_EXPECT_EQ(test, 0x0000000000000006ull, GENMASK_U128(2, 1)); + KUNIT_EXPECT_EQ(test, 0x00000000ffffffffull, GENMASK_U128(31, 0)); + KUNIT_EXPECT_EQ(test, 0x000000ffffe00000ull, GENMASK_U128(39, 21)); + KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, GENMASK_U128(63, 0)); + + /* Above 64 bit masks - only 64 bit portion can be validated once */ + KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, GENMASK_U128(64, 0) >> 1); + KUNIT_EXPECT_EQ(test, 0x00000000ffffffffull, GENMASK_U128(81, 50) >> 50); + KUNIT_EXPECT_EQ(test, 0x0000000000ffffffull, GENMASK_U128(87, 64) >> 64); + KUNIT_EXPECT_EQ(test, 0x0000000000ff0000ull, GENMASK_U128(87, 80) >> 64); + + KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, GENMASK_U128(127, 0) >> 64); + KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, (u64)GENMASK_U128(127, 0)); + KUNIT_EXPECT_EQ(test, 0x0000000000000003ull, GENMASK_U128(127, 126) >> 126); + KUNIT_EXPECT_EQ(test, 0x0000000000000001ull, GENMASK_U128(127, 127) >> 127); +#ifdef TEST_GENMASK_FAILURES + /* these should fail compilation */ + GENMASK_U128(0, 1); + GENMASK_U128(0, 10); + GENMASK_U128(9, 10); +#endif /* TEST_GENMASK_FAILURES */ +#endif /* CONFIG_ARCH_SUPPORTS_INT128 */ +} + +static void genmask_input_check_test(struct kunit *test) +{ + unsigned int x, y; + int z, w; + + /* Unknown input */ + KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(x, 0)); + KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(0, x)); + KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(x, y)); + + KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(z, 0)); + KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(0, z)); + KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(z, w)); + + /* Valid input */ + KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(1, 1)); + KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(39, 21)); + KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(100, 80)); + KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(110, 65)); + KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(127, 0)); +} + + +static struct kunit_case bits_test_cases[] = { + KUNIT_CASE(__genmask_test), + KUNIT_CASE(__genmask_ull_test), + KUNIT_CASE(genmask_test), + KUNIT_CASE(genmask_ull_test), + KUNIT_CASE(genmask_u128_test), + KUNIT_CASE(genmask_input_check_test), + {} +}; + +static struct kunit_suite bits_test_suite = { + .name = "bits-test", + .test_cases = bits_test_cases, +}; +kunit_test_suite(bits_test_suite); + +MODULE_DESCRIPTION("Test cases for functions and macros in bits.h"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1