KVM: selftests: Add KVM syscall wrappers for pthread_{cancel,join}()

Add and use KVM wrappers for pthread_{cancel,join}() so that selftests
don't need to manually assert that the syscalls succeeded.

Note, the vast majority tests don't actually assert success, but they all
obviously rely on the syscall to succeed.

Other than explicitly failing if a syscall fails, no functional change
intended.

Link: https://patch.msgid.link/20260731195612.2697986-10-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

tools/testing/selftests/kvm/arch_timer.c

@@ -158,10 +158,10 @@ static void test_run(struct kvm_vm *vm)
 	}
 
 	for (i = 0; i < test_args.nr_vcpus; i++)
-		pthread_join(pt_vcpu_run[i], NULL);
+		kvm_pthread_join(pt_vcpu_run[i], NULL);
 
 	if (test_args.migration_freq_ms)
-		pthread_join(pt_vcpu_migration, NULL);
+		kvm_pthread_join(pt_vcpu_migration, NULL);
 
 	bitmap_free(vcpu_done_map);
 }

tools/testing/selftests/kvm/arm64/vgic_irq.c

@@ -1007,8 +1007,8 @@ static void test_vgic_two_cpus(void *gcode)
 	kvm_pthread_create(&thr[0], NULL, test_vcpu_run, vcpus[0]);
 	kvm_pthread_create(&thr[1], NULL, test_vcpu_run, vcpus[1]);
 
-	pthread_join(thr[0], NULL);
-	pthread_join(thr[1], NULL);
+	kvm_pthread_join(thr[0], NULL);
+	kvm_pthread_join(thr[1], NULL);
 
 	close(gic_fd);
 	kvm_vm_free(vm);

tools/testing/selftests/kvm/arm64/vgic_lpi_stress.c

@@ -321,13 +321,13 @@ static void run_test(void)
 	clock_gettime(CLOCK_MONOTONIC, &start);
 
 	for (i = 0; i < nr_devices; i++)
-		pthread_join(lpi_threads[i], NULL);
+		kvm_pthread_join(lpi_threads[i], NULL);
 
 	delta = timespec_elapsed(start);
 	write_guest_global(vm, test_data.request_vcpus_stop, true);
 
 	for (i = 0; i < nr_vcpus; i++)
-		pthread_join(vcpu_threads[i], NULL);
+		kvm_pthread_join(vcpu_threads[i], NULL);
 
 	report_stats(delta);
 }

tools/testing/selftests/kvm/dirty_log_test.c

@@ -805,7 +805,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	WRITE_ONCE(host_quit, true);
 	sem_post(&sem_vcpu_cont);
 
-	pthread_join(vcpu_thread, NULL);
+	kvm_pthread_join(vcpu_thread, NULL);
 
 	pr_info("Total bits checked: dirty (%lu), clear (%lu)\n",
 		host_dirty_count, host_clear_count);

tools/testing/selftests/kvm/include/kvm_syscalls.h

@@ -101,6 +101,8 @@ __KVM_SYSCALL_DEFINE(sched_setaffinity, 3, pid_t, pid, size_t, cpusetsize, cpu_s
 typedef void *(*pthread_fn_t)(void *);
 __KVM_SYSCALL_DEFINE(pthread_create, 4, pthread_t *, thread,
 		     const pthread_attr_t *, attr, pthread_fn_t, fn, void *, arg);
+__KVM_SYSCALL_DEFINE(pthread_join, 2, pthread_t, thread, void **, thread_return);
+__KVM_SYSCALL_DEFINE(pthread_cancel, 1, pthread_t, thread);
 
 #define kvm_free_fd(fd)		\
 do {				\

tools/testing/selftests/kvm/irq_test.c

@@ -356,7 +356,7 @@ int main(int argc, char **argv)
 	WRITE_AND_SYNC_TO_GUEST(vm, done, true);
 
 	for (i = 0; i < nr_vcpus; i++)
-		pthread_join(vcpu_threads[i], NULL);
+		kvm_pthread_join(vcpu_threads[i], NULL);
 
 	return 0;
 }

tools/testing/selftests/kvm/irqfd_test.c

@@ -139,5 +139,5 @@ int main(int argc, char *argv[])
 	}
 
 	WRITE_ONCE(done, true);
-	pthread_join(racing_thread, NULL);
+	kvm_pthread_join(racing_thread, NULL);
 }

tools/testing/selftests/kvm/kvm_page_table_test.c

@@ -413,7 +413,7 @@ static void run_test(enum vm_guest_mode mode, void *arg)
 	}
 
 	for (i = 0; i < nr_vcpus; i++)
-		pthread_join(vcpu_threads[i], NULL);
+		kvm_pthread_join(vcpu_threads[i], NULL);
 
 	ret = sem_destroy(&test_stage_updated);
 	TEST_ASSERT(ret == 0, "Error in sem_destroy");

tools/testing/selftests/kvm/lib/memstress.c

@@ -312,7 +312,7 @@ void memstress_join_vcpu_threads(int nr_vcpus)
 	WRITE_ONCE(memstress_args.stop_vcpus, true);
 
 	for (i = 0; i < nr_vcpus; i++)
-		pthread_join(vcpu_threads[i].thread, NULL);
+		kvm_pthread_join(vcpu_threads[i].thread, NULL);
 }
 
 static void toggle_dirty_logging(struct kvm_vm *vm, int slots, bool enable)

tools/testing/selftests/kvm/lib/userfaultfd_util.c

@@ -187,8 +187,7 @@ void uffd_stop_demand_paging(struct uffd_desc *uffd)
 			    "Unable to write to pipefd %i for uffd_desc %p", i, uffd);
 
 	for (i = 0; i < uffd->num_readers; ++i)
-		TEST_ASSERT(!pthread_join(uffd->readers[i], NULL),
-			    "Pthread_join failed on reader %i for uffd_desc %p", i, uffd);
+		kvm_pthread_join(uffd->readers[i], NULL);
 
 	close(uffd->uffd);
 

tools/testing/selftests/kvm/memslot_perf_test.c

@@ -381,7 +381,7 @@ static void free_vm(struct vm_data *data)
 
 static void wait_guest_exit(struct vm_data *data)
 {
-	pthread_join(data->vcpu_thread, NULL);
+	kvm_pthread_join(data->vcpu_thread, NULL);
 }
 
 static void let_guest_run(struct sync_area *sync)

tools/testing/selftests/kvm/mmu_stress_test.c

@@ -409,7 +409,7 @@ int main(int argc, char *argv[])
 
 	/* Sanity check that the vCPUs actually ran. */
 	for (i = 0; i < nr_vcpus; i++)
-		pthread_join(threads[i], NULL);
+		kvm_pthread_join(threads[i], NULL);
 
 	/*
 	 * Deliberately exit without deleting the remaining memslots or closing

tools/testing/selftests/kvm/pre_fault_memory_test.c

@@ -116,7 +116,7 @@ static void pre_fault_memory(struct kvm_vcpu *vcpu, u64 base_gpa, u64 offset,
 		 */
 		if (!slot_recreated) {
 			WRITE_ONCE(data.recreate_slot, true);
-			pthread_join(slot_worker, NULL);
+			kvm_pthread_join(slot_worker, NULL);
 			slot_recreated = true;
 
 			/*

tools/testing/selftests/kvm/rseq_test.c

@@ -312,7 +312,7 @@ int main(int argc, char *argv[])
 		    "  e.g. via cpuidle.off=1 or via -l <latency>, or run with -u to\n"
 		    "  disable this sanity check.", i);
 
-	pthread_join(migration_thread, NULL);
+	kvm_pthread_join(migration_thread, NULL);
 
 	kvm_vm_free(vm);
 

tools/testing/selftests/kvm/s390/memop.c

@@ -701,7 +701,7 @@ static void test_cmpxchg_key_concurrent(void)
 		}
 	}
 
-	pthread_join(thread, NULL);
+	kvm_pthread_join(thread, NULL);
 
 	MOP(t.vcpu, LOGICAL, READ, mem2, max_block, GADDR_V(mem2));
 	TEST_ASSERT(popcount_eq(*(__uint128_t *)mem1, *(__uint128_t *)mem2),

tools/testing/selftests/kvm/set_memory_region_test.c

@@ -216,7 +216,7 @@ static void test_move_memory_region(bool disable_slot_zap_quirk)
 	/* Defered sync from when the memslot was misaligned (above). */
 	wait_for_vcpu();
 
-	pthread_join(vcpu_thread, NULL);
+	kvm_pthread_join(vcpu_thread, NULL);
 
 	kvm_vm_free(vm);
 }
@@ -302,7 +302,7 @@ static void test_delete_memory_region(bool disable_slot_zap_quirk)
 	 */
 	vm_mem_region_delete(vm, 0);
 
-	pthread_join(vcpu_thread, NULL);
+	kvm_pthread_join(vcpu_thread, NULL);
 
 	run = vcpu->run;
 

tools/testing/selftests/kvm/steal_time.c

@@ -557,7 +557,7 @@ int main(int ac, char **av)
 		do
 			sched_yield();
 		while (get_run_delay() - run_delay < MIN_RUN_DELAY_NS);
-		pthread_join(thread, NULL);
+		kvm_pthread_join(thread, NULL);
 		run_delay = get_run_delay() - run_delay;
 		TEST_ASSERT(run_delay >= MIN_RUN_DELAY_NS,
 			    "Expected run_delay >= %ld, got %ld",

tools/testing/selftests/kvm/x86/hyperv_ipi.c

@@ -225,15 +225,9 @@ static void *vcpu_thread(void *arg)
 static void cancel_join_vcpu_thread(pthread_t thread, struct kvm_vcpu *vcpu)
 {
 	void *retval;
-	int r;
 
-	r = pthread_cancel(thread);
-	TEST_ASSERT(!r, "pthread_cancel on vcpu_id=%d failed with errno=%d",
-		    vcpu->id, r);
-
-	r = pthread_join(thread, &retval);
-	TEST_ASSERT(!r, "pthread_join on vcpu_id=%d failed with errno=%d",
-		    vcpu->id, r);
+	kvm_pthread_cancel(thread);
+	kvm_pthread_join(thread, &retval);
 	TEST_ASSERT(retval == PTHREAD_CANCELED,
 		    "expected retval=%p, got %p", PTHREAD_CANCELED,
 		    retval);

tools/testing/selftests/kvm/x86/hyperv_tlb_flush.c

@@ -551,15 +551,9 @@ static void *vcpu_thread(void *arg)
 static void cancel_join_vcpu_thread(pthread_t thread, struct kvm_vcpu *vcpu)
 {
 	void *retval;
-	int r;
 
-	r = pthread_cancel(thread);
-	TEST_ASSERT(!r, "pthread_cancel on vcpu_id=%d failed with errno=%d",
-		    vcpu->id, r);
-
-	r = pthread_join(thread, &retval);
-	TEST_ASSERT(!r, "pthread_join on vcpu_id=%d failed with errno=%d",
-		    vcpu->id, r);
+	kvm_pthread_cancel(thread);
+	kvm_pthread_join(thread, &retval);
 	TEST_ASSERT(retval == PTHREAD_CANCELED,
 		    "expected retval=%p, got %p", PTHREAD_CANCELED,
 		    retval);

tools/testing/selftests/kvm/x86/private_mem_conversions_test.c

@@ -418,7 +418,7 @@ static void test_mem_conversions(enum vm_mem_backing_src_type src_type, u32 nr_v
 	WRITE_ONCE(run_vcpus, true);
 
 	for (i = 0; i < nr_vcpus; i++)
-		pthread_join(threads[i], NULL);
+		kvm_pthread_join(threads[i], NULL);
 
 	kvm_vm_free(vm);
 

tools/testing/selftests/kvm/x86/private_mem_kvm_exits_test.c

@@ -70,7 +70,7 @@ static void test_private_access_memslot_deleted(void)
 
 	vm_mem_region_delete(vm, EXITS_TEST_SLOT);
 
-	pthread_join(vm_thread, &thread_return);
+	kvm_pthread_join(vm_thread, &thread_return);
 	exit_reason = (u32)(u64)thread_return;
 
 	TEST_ASSERT_EQ(exit_reason, KVM_EXIT_MEMORY_FAULT);

tools/testing/selftests/kvm/x86/recalc_apic_map_test.c

@@ -65,8 +65,8 @@ int main(void)
 		vcpu_set_msr(vcpuN, MSR_IA32_APICBASE, LAPIC_DISABLED);
 	}
 
-	TEST_ASSERT_EQ(pthread_cancel(thread), 0);
-	TEST_ASSERT_EQ(pthread_join(thread, NULL), 0);
+	kvm_pthread_cancel(thread);
+	kvm_pthread_join(thread, NULL);
 
 	kvm_vm_free(vm);
 

tools/testing/selftests/kvm/x86/sev_migrate_tests.c

@@ -131,7 +131,7 @@ static void test_sev_migrate_locking(void)
 		kvm_pthread_create(&pt[i], NULL, locking_test_thread, &input[i]);
 
 	for (i = 0; i < NR_LOCK_TESTING_THREADS; ++i)
-		pthread_join(pt[i], NULL);
+		kvm_pthread_join(pt[i], NULL);
 	for (i = 0; i < NR_LOCK_TESTING_THREADS; ++i)
 		kvm_vm_free(input[i].vm);
 }

tools/testing/selftests/kvm/x86/sync_regs_test.c

@@ -199,8 +199,8 @@ static void race_sync_regs(struct kvm_vcpu *vcpu, void *racer)
 		}
 	}
 
-	TEST_ASSERT_EQ(pthread_cancel(thread), 0);
-	TEST_ASSERT_EQ(pthread_join(thread, NULL), 0);
+	kvm_pthread_cancel(thread);
+	kvm_pthread_join(thread, NULL);
 
 	kvm_x86_state_cleanup(state);
 }

tools/testing/selftests/kvm/x86/tsc_scaling_sync.c

@@ -99,7 +99,7 @@ int main(int argc, char *argv[])
 	unsigned long failures = 0;
 	for (cpu = 0; cpu < NR_TEST_VCPUS; cpu++) {
 		void *this_cpu_failures;
-		pthread_join(cpu_threads[cpu], &this_cpu_failures);
+		kvm_pthread_join(cpu_threads[cpu], &this_cpu_failures);
 		failures += (unsigned long)this_cpu_failures;
 	}
 

tools/testing/selftests/kvm/x86/xapic_ipi_test.c

@@ -231,17 +231,9 @@ static void *vcpu_thread(void *arg)
 static void cancel_join_vcpu_thread(pthread_t thread, struct kvm_vcpu *vcpu)
 {
 	void *retval;
-	int r;
 
-	r = pthread_cancel(thread);
-	TEST_ASSERT(r == 0,
-		    "pthread_cancel on vcpu_id=%d failed with errno=%d",
-		    vcpu->id, r);
-
-	r = pthread_join(thread, &retval);
-	TEST_ASSERT(r == 0,
-		    "pthread_join on vcpu_id=%d failed with errno=%d",
-		    vcpu->id, r);
+	kvm_pthread_cancel(thread);
+	kvm_pthread_join(thread, &retval);
 	TEST_ASSERT(retval == PTHREAD_CANCELED,
 		    "expected retval=%p, got %p", PTHREAD_CANCELED,
 		    retval);

tools/testing/selftests/kvm/x86/xen_shinfo_test.c

@@ -437,7 +437,6 @@ int main(int argc, char *argv[])
 	struct kvm_vm *vm;
 	pthread_t thread;
 	bool verbose;
-	int ret;
 
 	verbose = argc > 1 && (!strncmp(argv[1], "-v", 3) ||
 			       !strncmp(argv[1], "--verbose", 10));
@@ -948,11 +947,8 @@ int main(int argc, char *argv[])
 				TEST_ASSERT(!evtchn_irq_expected,
 					    "Expected event channel IRQ but it didn't happen");
 
-				ret = pthread_cancel(thread);
-				TEST_ASSERT(ret == 0, "pthread_cancel() failed: %s", strerror(ret));
-
-				ret = pthread_join(thread, 0);
-				TEST_ASSERT(ret == 0, "pthread_join() failed: %s", strerror(ret));
+				kvm_pthread_cancel(thread);
+				kvm_pthread_join(thread, 0);
 				goto done;
 
 			case TEST_GUEST_SAW_IRQ: