KVM: selftests: move common startup logic to kvm_util.c

Consolidate common startup logic in one place by implementing a single
setup function with __attribute((constructor)) for all selftests within
kvm_util.c.

This allows moving logic like:
        /* Tell stdout not to buffer its content */
        setbuf(stdout, NULL);
to a single file for all selftests.

This will also allow any required setup at entry in future to be done in
common main function.

Link: https://lore.kernel.org/lkml/Ywa9T+jKUpaHLu%2Fl@google.com
Suggested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
Reviewed-by: Peter Gonda <pgonda@google.com>
Signed-off-by: Vishal Annapurve <vannapurve@google.com>
Link: https://lore.kernel.org/r/20221115213845.3348210-2-vannapurve@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

20 files changed, 6 insertions, 54 deletions

diff --git a/tools/testing/selftests/kvm/aarch64/arch_timer.c b/tools/testing/selftests/kvm/aarch64/arch_timer.c
index 54016cdd8a09..f2a96779716a 100644
--- a/tools/testing/selftests/kvm/aarch64/arch_timer.c
+++ b/tools/testing/selftests/kvm/aarch64/arch_timer.c
@@ -446,9 +446,6 @@ int main(int argc, char *argv[])
 {
 	struct kvm_vm *vm;
 
-	/* Tell stdout not to buffer its content */
-	setbuf(stdout, NULL);
-
 	if (!parse_args(argc, argv))
 		exit(KSFT_SKIP);
 
diff --git a/tools/testing/selftests/kvm/aarch64/hypercalls.c b/tools/testing/selftests/kvm/aarch64/hypercalls.c
index 3dceecfd1f62..bef1499fb465 100644
--- a/tools/testing/selftests/kvm/aarch64/hypercalls.c
+++ b/tools/testing/selftests/kvm/aarch64/hypercalls.c
@@ -305,8 +305,6 @@ static void test_run(void)
 
 int main(void)
 {
-	setbuf(stdout, NULL);
-
 	test_run();
 	return 0;
 }
diff --git a/tools/testing/selftests/kvm/aarch64/vgic_irq.c b/tools/testing/selftests/kvm/aarch64/vgic_irq.c
index e0310ebc313c..90d854e0fcff 100644
--- a/tools/testing/selftests/kvm/aarch64/vgic_irq.c
+++ b/tools/testing/selftests/kvm/aarch64/vgic_irq.c
@@ -817,9 +817,6 @@ int main(int argc, char **argv)
 	int opt;
 	bool eoi_split = false;
 
-	/* Tell stdout not to buffer its content */
-	setbuf(stdout, NULL);
-
 	while ((opt = getopt(argc, argv, "hn:e:l:")) != -1) {
 		switch (opt) {
 		case 'n':
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 07c8edd4e548..575a0c38d1c0 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -2086,3 +2086,9 @@ void __vm_get_stat(struct kvm_vm *vm, const char *stat_name, uint64_t *data,
 		break;
 	}
 }
+
+void __attribute((constructor)) kvm_selftest_init(void)
+{
+	/* Tell stdout not to buffer its content. */
+	setbuf(stdout, NULL);
+}
diff --git a/tools/testing/selftests/kvm/memslot_perf_test.c b/tools/testing/selftests/kvm/memslot_perf_test.c
index d771262ea584..36b20abfb948 100644
--- a/tools/testing/selftests/kvm/memslot_perf_test.c
+++ b/tools/testing/selftests/kvm/memslot_perf_test.c
@@ -994,9 +994,6 @@ int main(int argc, char *argv[])
 	struct test_result rbestslottime;
 	int tctr;
 
-	/* Tell stdout not to buffer its content */
-	setbuf(stdout, NULL);
-
 	if (!parse_args(argc, argv, &targs))
 		return -1;
 
diff --git a/tools/testing/selftests/kvm/rseq_test.c b/tools/testing/selftests/kvm/rseq_test.c
index 0e9e2b48a51f..3045fdf9bdf5 100644
--- a/tools/testing/selftests/kvm/rseq_test.c
+++ b/tools/testing/selftests/kvm/rseq_test.c
@@ -205,9 +205,6 @@ int main(int argc, char *argv[])
 	struct kvm_vcpu *vcpu;
 	u32 cpu, rseq_cpu;
 
-	/* Tell stdout not to buffer its content */
-	setbuf(stdout, NULL);
-
 	r = sched_getaffinity(0, sizeof(possible_mask), &possible_mask);
 	TEST_ASSERT(!r, "sched_getaffinity failed, errno = %d (%s)", errno,
 		    strerror(errno));
diff --git a/tools/testing/selftests/kvm/s390x/memop.c b/tools/testing/selftests/kvm/s390x/memop.c
index 9113696d5178..3fd81e58f40c 100644
--- a/tools/testing/selftests/kvm/s390x/memop.c
+++ b/tools/testing/selftests/kvm/s390x/memop.c
@@ -760,8 +760,6 @@ int main(int argc, char *argv[])
 
 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_S390_MEM_OP));
 
-	setbuf(stdout, NULL);	/* Tell stdout not to buffer its content */
-
 	ksft_print_header();
 
 	ksft_set_plan(ARRAY_SIZE(testlist));
diff --git a/tools/testing/selftests/kvm/s390x/resets.c b/tools/testing/selftests/kvm/s390x/resets.c
index 19486084eb30..e41e2cb8ffa9 100644
--- a/tools/testing/selftests/kvm/s390x/resets.c
+++ b/tools/testing/selftests/kvm/s390x/resets.c
@@ -296,8 +296,6 @@ int main(int argc, char *argv[])
 	bool has_s390_vcpu_resets = kvm_check_cap(KVM_CAP_S390_VCPU_RESETS);
 	int idx;
 
-	setbuf(stdout, NULL);	/* Tell stdout not to buffer its content */
-
 	ksft_print_header();
 	ksft_set_plan(ARRAY_SIZE(testlist));
 
diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
index 3fdb6e2598eb..2ddde41c44ba 100644
--- a/tools/testing/selftests/kvm/s390x/sync_regs_test.c
+++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
@@ -231,9 +231,6 @@ int main(int argc, char *argv[])
 
 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_SYNC_REGS));
 
-	/* Tell stdout not to buffer its content */
-	setbuf(stdout, NULL);
-
 	ksft_print_header();
 
 	ksft_set_plan(ARRAY_SIZE(testlist));
diff --git a/tools/testing/selftests/kvm/set_memory_region_test.c b/tools/testing/selftests/kvm/set_memory_region_test.c
index 85c16f09a50e..2ef1d1b72ce4 100644
--- a/tools/testing/selftests/kvm/set_memory_region_test.c
+++ b/tools/testing/selftests/kvm/set_memory_region_test.c
@@ -392,9 +392,6 @@ int main(int argc, char *argv[])
 	int i, loops;
 #endif
 
-	/* Tell stdout not to buffer its content */
-	setbuf(stdout, NULL);
-
 #ifdef __x86_64__
 	/*
 	 * FIXME: the zero-memslot test fails on aarch64 and s390x because
diff --git a/tools/testing/selftests/kvm/x86_64/cr4_cpuid_sync_test.c b/tools/testing/selftests/kvm/x86_64/cr4_cpuid_sync_test.c
index 4208487652f8..1027a671c7d3 100644
--- a/tools/testing/selftests/kvm/x86_64/cr4_cpuid_sync_test.c
+++ b/tools/testing/selftests/kvm/x86_64/cr4_cpuid_sync_test.c
@@ -57,9 +57,6 @@ int main(int argc, char *argv[])
 
 	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_XSAVE));
 
-	/* Tell stdout not to buffer its content */
-	setbuf(stdout, NULL);
-
 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
 	run = vcpu->run;
 
diff --git a/tools/testing/selftests/kvm/x86_64/emulator_error_test.c b/tools/testing/selftests/kvm/x86_64/emulator_error_test.c
index 1abb34735754..d945e571e7a0 100644
--- a/tools/testing/selftests/kvm/x86_64/emulator_error_test.c
+++ b/tools/testing/selftests/kvm/x86_64/emulator_error_test.c
@@ -157,9 +157,6 @@ int main(int argc, char *argv[])
 	uint64_t gpa;
 	int rc;
 
-	/* Tell stdout not to buffer its content */
-	setbuf(stdout, NULL);
-
 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_SMALLER_MAXPHYADDR));
 
 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
diff --git a/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c b/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c
index e804eb08dff9..5c27efbf405e 100644
--- a/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c
+++ b/tools/testing/selftests/kvm/x86_64/hyperv_cpuid.c
@@ -134,9 +134,6 @@ int main(int argc, char *argv[])
 	const struct kvm_cpuid2 *hv_cpuid_entries;
 	struct kvm_vcpu *vcpu;
 
-	/* Tell stdout not to buffer its content */
-	setbuf(stdout, NULL);
-
 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_CPUID));
 
 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
diff --git a/tools/testing/selftests/kvm/x86_64/platform_info_test.c b/tools/testing/selftests/kvm/x86_64/platform_info_test.c
index 76417c7d687b..310a104d94f0 100644
--- a/tools/testing/selftests/kvm/x86_64/platform_info_test.c
+++ b/tools/testing/selftests/kvm/x86_64/platform_info_test.c
@@ -72,9 +72,6 @@ int main(int argc, char *argv[])
 	struct kvm_vm *vm;
 	uint64_t msr_platform_info;
 
-	/* Tell stdout not to buffer its content */
-	setbuf(stdout, NULL);
-
 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_MSR_PLATFORM_INFO));
 
 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
diff --git a/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c b/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c
index ea4e259a1e2e..a6ffa245c897 100644
--- a/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c
+++ b/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c
@@ -447,9 +447,6 @@ int main(int argc, char *argv[])
 	struct kvm_vcpu *vcpu;
 	struct kvm_vm *vm;
 
-	/* Tell stdout not to buffer its content */
-	setbuf(stdout, NULL);
-
 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_PMU_EVENT_FILTER));
 
 	TEST_REQUIRE(use_intel_pmu() || use_amd_pmu());
diff --git a/tools/testing/selftests/kvm/x86_64/set_sregs_test.c b/tools/testing/selftests/kvm/x86_64/set_sregs_test.c
index 2bb08bf2125d..a284fcef6ed7 100644
--- a/tools/testing/selftests/kvm/x86_64/set_sregs_test.c
+++ b/tools/testing/selftests/kvm/x86_64/set_sregs_test.c
@@ -82,9 +82,6 @@ int main(int argc, char *argv[])
 	uint64_t cr4;
 	int rc;
 
-	/* Tell stdout not to buffer its content */
-	setbuf(stdout, NULL);
-
 	/*
 	 * Create a dummy VM, specifically to avoid doing KVM_SET_CPUID2, and
 	 * use it to verify all supported CR4 bits can be set prior to defining
diff --git a/tools/testing/selftests/kvm/x86_64/svm_nested_soft_inject_test.c b/tools/testing/selftests/kvm/x86_64/svm_nested_soft_inject_test.c
index e637d7736012..e497ace629c1 100644
--- a/tools/testing/selftests/kvm/x86_64/svm_nested_soft_inject_test.c
+++ b/tools/testing/selftests/kvm/x86_64/svm_nested_soft_inject_test.c
@@ -194,9 +194,6 @@ done:
 
 int main(int argc, char *argv[])
 {
-	/* Tell stdout not to buffer its content */
-	setbuf(stdout, NULL);
-
 	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_SVM));
 
 	TEST_ASSERT(kvm_cpu_has(X86_FEATURE_NRIPS),
diff --git a/tools/testing/selftests/kvm/x86_64/sync_regs_test.c b/tools/testing/selftests/kvm/x86_64/sync_regs_test.c
index 9b6db0b0b13e..d2f9b5bdfab2 100644
--- a/tools/testing/selftests/kvm/x86_64/sync_regs_test.c
+++ b/tools/testing/selftests/kvm/x86_64/sync_regs_test.c
@@ -90,9 +90,6 @@ int main(int argc, char *argv[])
 	struct kvm_vcpu_events events;
 	int rv, cap;
 
-	/* Tell stdout not to buffer its content */
-	setbuf(stdout, NULL);
-
 	cap = kvm_check_cap(KVM_CAP_SYNC_REGS);
 	TEST_REQUIRE((cap & TEST_SYNC_FIELDS) == TEST_SYNC_FIELDS);
 	TEST_REQUIRE(!(cap & INVALID_SYNC_FIELD));
diff --git a/tools/testing/selftests/kvm/x86_64/userspace_io_test.c b/tools/testing/selftests/kvm/x86_64/userspace_io_test.c
index 7316521428f8..91076c9787b4 100644
--- a/tools/testing/selftests/kvm/x86_64/userspace_io_test.c
+++ b/tools/testing/selftests/kvm/x86_64/userspace_io_test.c
@@ -56,9 +56,6 @@ int main(int argc, char *argv[])
 	struct kvm_vm *vm;
 	struct ucall uc;
 
-	/* Tell stdout not to buffer its content */
-	setbuf(stdout, NULL);
-
 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
 	run = vcpu->run;
 
diff --git a/tools/testing/selftests/kvm/x86_64/userspace_msr_exit_test.c b/tools/testing/selftests/kvm/x86_64/userspace_msr_exit_test.c
index fae95089e655..25fa55344a10 100644
--- a/tools/testing/selftests/kvm/x86_64/userspace_msr_exit_test.c
+++ b/tools/testing/selftests/kvm/x86_64/userspace_msr_exit_test.c
@@ -818,9 +818,6 @@ static void test_user_exit_msr_flags(void)
 
 int main(int argc, char *argv[])
 {
-	/* Tell stdout not to buffer its content */
-	setbuf(stdout, NULL);
-
 	test_msr_filter_allow();
 
 	test_msr_filter_deny();