kernel/linux.git/tools/testing/selftests/kvm/lib/test_util.c, branch v6.19.11

KVM: selftests: Add wrapper macro to handle and assert on expected SIGBUS

2025-10-10T21:25:29+00:00

Extract the guest_memfd test's SIGBUS handling functionality into a common TEST_EXPECT_SIGBUS() macro in anticipation of adding more SIGBUS testcases. Eating a SIGBUS isn't terrible difficult, but it requires a non-trivial amount of boilerplate code, and using a macro allows selftests to print out the exact action that failed to generate a SIGBUS without the developer needing to remember to add a useful error message. Explicitly mark the SIGBUS handler as "used", as gcc-14 at least likes to discard the function before linking. Opportunistically use TEST_FAIL(...) instead of TEST_ASSERT(false, ...), and fix the write path of the guest_memfd test to use the local "val" instead of hardcoding the literal value a second time. Suggested-by: Ackerley Tng Reviewed-by: Ackerley Tng Tested-by: Ackerley Tng Reviewed-by: Lisa Wang Tested-by: Lisa Wang Link: https://lore.kernel.org/r/20251003232606.4070510-12-seanjc@google.com Signed-off-by: Sean Christopherson

KVM: selftests: access_tracking_perf_test: Add option to skip the sanity check

2025-05-16T18:45:12+00:00

Add an option to skip sanity check of number of still idle pages, and set it by default to skip, in case hypervisor or NUMA balancing is detected. Signed-off-by: Maxim Levitsky Co-developed-by: James Houghton Signed-off-by: James Houghton Reviewed-by: Maxim Levitsky Link: https://lore.kernel.org/r/20250508184649.2576210-3-jthoughton@google.com Signed-off-by: Sean Christopherson

KVM: selftests: Extract guts of THP accessor to standalone sysfs helpers

2025-05-16T16:35:26+00:00

Extract the guts of thp_configured() and get_trans_hugepagesz() to standalone helpers so that the core logic can be reused for other sysfs files, e.g. to query numa_balancing. Opportunistically assert that the initial fscanf() read at least one byte, and add a comment explaining the second call to fscanf(). Signed-off-by: Maxim Levitsky Signed-off-by: James Houghton Link: https://lore.kernel.org/r/20250508184649.2576210-2-jthoughton@google.com Signed-off-by: Sean Christopherson

KVM: selftests: Define _GNU_SOURCE for all selftests code

2024-04-29T19:49:10+00:00

Define _GNU_SOURCE is the base CFLAGS instead of relying on selftests to manually #define _GNU_SOURCE, which is repetitive and error prone. E.g. kselftest_harness.h requires _GNU_SOURCE for asprintf(), but if a selftest includes kvm_test_harness.h after stdio.h, the include guards result in the effective version of stdio.h consumed by kvm_test_harness.h not defining asprintf(): In file included from x86_64/fix_hypercall_test.c:12: In file included from include/kvm_test_harness.h:11: ../kselftest_harness.h:1169:2: error: call to undeclared function 'asprintf'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] 1169 | asprintf(&test_name, "%s%s%s.%s", f->name, | ^ When including the rseq selftest's "library" code, #undef _GNU_SOURCE so that rseq.c controls whether or not it wants to build with _GNU_SOURCE. Reported-by: Muhammad Usama Anjum Acked-by: Claudio Imbrenda Acked-by: Oliver Upton Acked-by: Anup Patel Reviewed-by: Muhammad Usama Anjum Link: https://lore.kernel.org/r/20240423190308.2883084-1-seanjc@google.com Signed-off-by: Sean Christopherson

KVM: selftests: Generalize check_clocksource() from kvm_clock_test

2024-02-01T16:58:13+00:00

Several existing x86 selftests need to check that the underlying system clocksource is TSC or based on TSC but every test implements its own check. As a first step towards unification, extract check_clocksource() from kvm_clock_test and split it into two functions: arch-neutral 'sys_get_cur_clocksource()' and x86-specific 'sys_clocksource_is_tsc()'. Fix a couple of pre-existing issues in kvm_clock_test: memory leakage in check_clocksource() and using TEST_ASSERT() instead of TEST_REQUIRE(). The change also makes the test fail when system clocksource can't be read from sysfs. Signed-off-by: Vitaly Kuznetsov Link: https://lore.kernel.org/r/20240109141121.1619463-2-vkuznets@redhat.com [sean: eliminate if-elif pattern just to set a bool true] Signed-off-by: Sean Christopherson

KVM: selftests: Assert that vasprintf() is successful

2023-09-20T16:26:31+00:00

Assert that vasprintf() succeeds as the "returned" string is undefined on failure. Checking the result also eliminates the only warning with default options in KVM selftests, i.e. is the only thing getting in the way of compile with -Werror. lib/test_util.c: In function ‘strdup_printf’: lib/test_util.c:390:9: error: ignoring return value of ‘vasprintf’ declared with attribute ‘warn_unused_result’ [-Werror=unused-result] 390 | vasprintf(&str, fmt, ap); | ^~~~~~~~~~~~~~~~~~~~~~~~ Don't bother capturing the return value, allegedly vasprintf() can only fail due to a memory allocation failure. Fixes: dfaf20af7649 ("KVM: arm64: selftests: Replace str_with_index with strdup_printf") Cc: Andrew Jones Cc: Haibo Xu Cc: Anup Patel Signed-off-by: Sean Christopherson Reviewed-by: Andrew Jones Tested-by: Andrew Jones Message-Id: <20230914010636.1391735-1-seanjc@google.com> Signed-off-by: Paolo Bonzini

KVM: arm64: selftests: Replace str_with_index with strdup_printf

2023-08-08T16:11:57+00:00

The original author of aarch64/get-reg-list.c (me) was wearing tunnel vision goggles when implementing str_with_index(). There's no reason to have such a special case string function. Instead, take inspiration from glib and implement strdup_printf. The implementation builds on vasprintf() which requires _GNU_SOURCE, but we require _GNU_SOURCE in most files already. Signed-off-by: Andrew Jones Signed-off-by: Haibo Xu Signed-off-by: Anup Patel

selftests: KVM: skip hugetlb tests if huge pages are not available

2023-03-14T14:20:06+00:00

Right now, if KVM memory stress tests are run with hugetlb sources but hugetlb is not available (either in the kernel or because /proc/sys/vm/nr_hugepages is 0) the test will fail with a memory allocation error. This makes it impossible to add tests that default to hugetlb-backed memory, because on a machine with a default configuration they will fail. Therefore, check HugePages_Total as well and, if zero, direct the user to enable hugepages in procfs. Furthermore, return KSFT_SKIP whenever hugetlb is not available. Signed-off-by: Paolo Bonzini

KVM: selftests: implement random number generator for guest code

2022-11-16T18:09:19+00:00

Implement random number generator for guest code to randomize parts of the test, making it less predictable and a more accurate reflection of reality. The random number generator chosen is the Park-Miller Linear Congruential Generator, a fancy name for a basic and well-understood random number generator entirely sufficient for this purpose. Signed-off-by: Colton Lewis Reviewed-by: Sean Christopherson Reviewed-by: David Matlack Link: https://lore.kernel.org/r/20221107182208.479157-2-coltonlewis@google.com Signed-off-by: Sean Christopherson

KVM: selftests: Add atoi_paranoid() to catch errors missed by atoi()

2022-11-16T18:03:24+00:00

atoi() doesn't detect errors. There is no way to know that a 0 return is correct conversion or due to an error. Introduce atoi_paranoid() to detect errors and provide correct conversion. Replace all atoi() calls with atoi_paranoid(). Signed-off-by: Vipin Sharma Suggested-by: David Matlack Suggested-by: Sean Christopherson Reviewed-by: Sean Christopherson Link: https://lore.kernel.org/r/20221103191719.1559407-4-vipinsh@google.com Signed-off-by: Sean Christopherson