From 2d0f2a648147d6bbf0655e03500586a6712a7281 Mon Sep 17 00:00:00 2001 From: Maxim Levitsky Date: Fri, 4 Oct 2024 18:01:53 -0400 Subject: KVM: selftests: memslot_perf_test: increase guest sync timeout When memslot_perf_test is run nested, first iteration of test_memslot_rw_loop testcase, sometimes takes more than 2 seconds due to build of shadow page tables. Following iterations are fast. To be on the safe side, bump the timeout to 10 seconds. Signed-off-by: Maxim Levitsky Tested-by: Liam Merwick Reviewed-by: Liam Merwick Link: https://lore.kernel.org/r/20241004220153.287459-1-mlevitsk@redhat.com Signed-off-by: Sean Christopherson --- tools/testing/selftests/kvm/memslot_perf_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools/testing') diff --git a/tools/testing/selftests/kvm/memslot_perf_test.c b/tools/testing/selftests/kvm/memslot_perf_test.c index 989ffe0d047f..e3711beff7f3 100644 --- a/tools/testing/selftests/kvm/memslot_perf_test.c +++ b/tools/testing/selftests/kvm/memslot_perf_test.c @@ -417,7 +417,7 @@ static bool _guest_should_exit(void) */ static noinline void host_perform_sync(struct sync_area *sync) { - alarm(2); + alarm(10); atomic_store_explicit(&sync->sync_flag, true, memory_order_release); while (atomic_load_explicit(&sync->sync_flag, memory_order_acquire)) -- cgit v1.2.3 From 945bdae20be5a13f1fcdcb14ec356dcbeee35839 Mon Sep 17 00:00:00 2001 From: Patrick Roy Date: Thu, 24 Oct 2024 10:59:53 +0100 Subject: KVM: selftests: fix unintentional noop test in guest_memfd_test.c The loop in test_create_guest_memfd_invalid() that is supposed to test that nothing is accepted as a valid flag to KVM_CREATE_GUEST_MEMFD was initializing `flag` as 0 instead of BIT(0). This caused the loop to immediately exit instead of iterating over BIT(0), BIT(1), ... . Fixes: 8a89efd43423 ("KVM: selftests: Add basic selftest for guest_memfd()") Signed-off-by: Patrick Roy Reviewed-by: James Gowans Reviewed-by: Muhammad Usama Anjum Link: https://lore.kernel.org/r/20241024095956.3668818-1-roypat@amazon.co.uk Signed-off-by: Sean Christopherson --- tools/testing/selftests/kvm/guest_memfd_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools/testing') diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing/selftests/kvm/guest_memfd_test.c index ba0c8e996035..ce687f8d248f 100644 --- a/tools/testing/selftests/kvm/guest_memfd_test.c +++ b/tools/testing/selftests/kvm/guest_memfd_test.c @@ -134,7 +134,7 @@ static void test_create_guest_memfd_invalid(struct kvm_vm *vm) size); } - for (flag = 0; flag; flag <<= 1) { + for (flag = BIT(0); flag; flag <<= 1) { fd = __vm_create_guest_memfd(vm, page_size, flag); TEST_ASSERT(fd == -1 && errno == EINVAL, "guest_memfd() with flag '0x%lx' should fail with EINVAL", -- cgit v1.2.3 From 5b188cc4866aaf712e896f92ac42c7802135e507 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 9 Oct 2024 08:49:41 -0700 Subject: KVM: selftests: Disable strict aliasing Disable strict aliasing, as has been done in the kernel proper for decades (literally since before git history) to fix issues where gcc will optimize away loads in code that looks 100% correct, but is _technically_ undefined behavior, and thus can be thrown away by the compiler. E.g. arm64's vPMU counter access test casts a uint64_t (unsigned long) pointer to a u64 (unsigned long long) pointer when setting PMCR.N via u64p_replace_bits(), which gcc-13 detects and optimizes away, i.e. ignores the result and uses the original PMCR. The issue is most easily observed by making set_pmcr_n() noinline and wrapping the call with printf(), e.g. sans comments, for this code: printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n); set_pmcr_n(&pmcr, pmcr_n); printf("orig = %lx, next = %lx, want = %lu\n", pmcr_orig, pmcr, pmcr_n); gcc-13 generates: 0000000000401c90 : 401c90: f9400002 ldr x2, [x0] 401c94: b3751022 bfi x2, x1, #11, #5 401c98: f9000002 str x2, [x0] 401c9c: d65f03c0 ret 0000000000402660 : 402724: aa1403e3 mov x3, x20 402728: aa1503e2 mov x2, x21 40272c: aa1603e0 mov x0, x22 402730: aa1503e1 mov x1, x21 402734: 940060ff bl 41ab30 <_IO_printf> 402738: aa1403e1 mov x1, x20 40273c: 910183e0 add x0, sp, #0x60 402740: 97fffd54 bl 401c90 402744: aa1403e3 mov x3, x20 402748: aa1503e2 mov x2, x21 40274c: aa1503e1 mov x1, x21 402750: aa1603e0 mov x0, x22 402754: 940060f7 bl 41ab30 <_IO_printf> with the value stored in [sp + 0x60] ignored by both printf() above and in the test proper, resulting in a false failure due to vcpu_set_reg() simply storing the original value, not the intended value. $ ./vpmu_counter_access Random seed: 0x6b8b4567 orig = 3040, next = 3040, want = 0 orig = 3040, next = 3040, want = 0 ==== Test Assertion Failure ==== aarch64/vpmu_counter_access.c:505: pmcr_n == get_pmcr_n(pmcr) pid=71578 tid=71578 errno=9 - Bad file descriptor 1 0x400673: run_access_test at vpmu_counter_access.c:522 2 (inlined by) main at vpmu_counter_access.c:643 3 0x4132d7: __libc_start_call_main at libc-start.o:0 4 0x413653: __libc_start_main at ??:0 5 0x40106f: _start at ??:0 Failed to update PMCR.N to 0 (received: 6) Somewhat bizarrely, gcc-11 also exhibits the same behavior, but only if set_pmcr_n() is marked noinline, whereas gcc-13 fails even if set_pmcr_n() is inlined in its sole caller. Cc: stable@vger.kernel.org Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116912 Signed-off-by: Sean Christopherson --- tools/testing/selftests/kvm/Makefile | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'tools/testing') diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 156fbfae940f..1896ef383cae 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -241,10 +241,10 @@ CFLAGS += -Wall -Wstrict-prototypes -Wuninitialized -O2 -g -std=gnu99 \ -Wno-gnu-variable-sized-type-not-at-end -MD -MP -DCONFIG_64BIT \ -fno-builtin-memcmp -fno-builtin-memcpy \ -fno-builtin-memset -fno-builtin-strnlen \ - -fno-stack-protector -fno-PIE -I$(LINUX_TOOL_INCLUDE) \ - -I$(LINUX_TOOL_ARCH_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude \ - -I$( Date: Wed, 30 Oct 2024 21:53:33 -0700 Subject: KVM: selftests: Don't force -march=x86-64-v2 if it's unsupported Force -march=x86-64-v2 to avoid SSE/AVX instructions if and only if the uarch definition is supported by the compiler, e.g. gcc 7.5 only supports x86-64. Fixes: 9a400068a158 ("KVM: selftests: x86: Avoid using SSE/AVX instructions") Cc: Vitaly Kuznetsov Reviewed-and-tested-by: Vitaly Kuznetsov Link: https://lore.kernel.org/r/20241031045333.1209195-1-seanjc@google.com Signed-off-by: Sean Christopherson --- tools/testing/selftests/kvm/Makefile | 2 ++ 1 file changed, 2 insertions(+) (limited to 'tools/testing') diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 1896ef383cae..48645a2e29da 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -249,8 +249,10 @@ ifeq ($(ARCH),s390) CFLAGS += -march=z10 endif ifeq ($(ARCH),x86) +ifeq ($(shell echo "void foo(void) { }" | $(CC) -march=x86-64-v2 -x c - -c -o /dev/null 2>/dev/null; echo "$$?"),0) CFLAGS += -march=x86-64-v2 endif +endif ifeq ($(ARCH),arm64) tools_dir := $(top_srcdir)/tools arm64_tools_dir := $(tools_dir)/arch/arm64/tools/ -- cgit v1.2.3