diff --git a/tools/testing/selftests/kvm/arch_timer.c b/tools/testing/selftests/kvm/arch_timer.c
index a6a66b5b7ea9..03160ad666f5 100644
--- a/tools/testing/selftests/kvm/arch_timer.c
+++ b/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);
 }
diff --git a/tools/testing/selftests/kvm/arm64/vgic_irq.c b/tools/testing/selftests/kvm/arm64/vgic_irq.c
index 2d6f20d5c117..3cb85932ee85 100644
--- a/tools/testing/selftests/kvm/arm64/vgic_irq.c
+++ b/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);
diff --git a/tools/testing/selftests/kvm/arm64/vgic_lpi_stress.c b/tools/testing/selftests/kvm/arm64/vgic_lpi_stress.c
index 549e0547d905..9a69c439a0f8 100644
--- a/tools/testing/selftests/kvm/arm64/vgic_lpi_stress.c
+++ b/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);
 }
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index ca22e5f09ac2..af5eb0334a74 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/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);
diff --git a/tools/testing/selftests/kvm/include/kvm_syscalls.h b/tools/testing/selftests/kvm/include/kvm_syscalls.h
index e75be8378779..d6c18e13b9c8 100644
--- a/tools/testing/selftests/kvm/include/kvm_syscalls.h
+++ b/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 {				\
diff --git a/tools/testing/selftests/kvm/irq_test.c b/tools/testing/selftests/kvm/irq_test.c
index 7da5f8d75e85..168c52734fef 100644
--- a/tools/testing/selftests/kvm/irq_test.c
+++ b/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;
 }
diff --git a/tools/testing/selftests/kvm/irqfd_test.c b/tools/testing/selftests/kvm/irqfd_test.c
index 8b39144a2834..ebb2478878de 100644
--- a/tools/testing/selftests/kvm/irqfd_test.c
+++ b/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);
 }
diff --git a/tools/testing/selftests/kvm/kvm_page_table_test.c b/tools/testing/selftests/kvm/kvm_page_table_test.c
index 8222bdb63e49..974813ea8953 100644
--- a/tools/testing/selftests/kvm/kvm_page_table_test.c
+++ b/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");
diff --git a/tools/testing/selftests/kvm/lib/memstress.c b/tools/testing/selftests/kvm/lib/memstress.c
index 0bfa623ce9b5..2864562f57b4 100644
--- a/tools/testing/selftests/kvm/lib/memstress.c
+++ b/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)
diff --git a/tools/testing/selftests/kvm/lib/userfaultfd_util.c b/tools/testing/selftests/kvm/lib/userfaultfd_util.c
index 4b3e3158ed87..f7ce5a6ddcc2 100644
--- a/tools/testing/selftests/kvm/lib/userfaultfd_util.c
+++ b/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);
 
diff --git a/tools/testing/selftests/kvm/memslot_perf_test.c b/tools/testing/selftests/kvm/memslot_perf_test.c
index eb49305db404..e1299611be32 100644
--- a/tools/testing/selftests/kvm/memslot_perf_test.c
+++ b/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)
diff --git a/tools/testing/selftests/kvm/mmu_stress_test.c b/tools/testing/selftests/kvm/mmu_stress_test.c
index 9448498849ff..741e343962ed 100644
--- a/tools/testing/selftests/kvm/mmu_stress_test.c
+++ b/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
diff --git a/tools/testing/selftests/kvm/pre_fault_memory_test.c b/tools/testing/selftests/kvm/pre_fault_memory_test.c
index 88287ccb9093..c57631aab3d3 100644
--- a/tools/testing/selftests/kvm/pre_fault_memory_test.c
+++ b/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;
 
 			/*
diff --git a/tools/testing/selftests/kvm/rseq_test.c b/tools/testing/selftests/kvm/rseq_test.c
index 0921b8d90d4a..b386aece68fd 100644
--- a/tools/testing/selftests/kvm/rseq_test.c
+++ b/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);
 
diff --git a/tools/testing/selftests/kvm/s390/memop.c b/tools/testing/selftests/kvm/s390/memop.c
index 96b32bd74009..ce8db96ccf7e 100644
--- a/tools/testing/selftests/kvm/s390/memop.c
+++ b/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),
diff --git a/tools/testing/selftests/kvm/set_memory_region_test.c b/tools/testing/selftests/kvm/set_memory_region_test.c
index 12f5022bb164..dffe9654f45b 100644
--- a/tools/testing/selftests/kvm/set_memory_region_test.c
+++ b/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;
 
diff --git a/tools/testing/selftests/kvm/steal_time.c b/tools/testing/selftests/kvm/steal_time.c
index e8dd524a41a2..83a1e3aa15cf 100644
--- a/tools/testing/selftests/kvm/steal_time.c
+++ b/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",
diff --git a/tools/testing/selftests/kvm/x86/hyperv_ipi.c b/tools/testing/selftests/kvm/x86/hyperv_ipi.c
index 3cf451f3153e..d2efb1043534 100644
--- a/tools/testing/selftests/kvm/x86/hyperv_ipi.c
+++ b/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);
diff --git a/tools/testing/selftests/kvm/x86/hyperv_tlb_flush.c b/tools/testing/selftests/kvm/x86/hyperv_tlb_flush.c
index 87fac1968a47..e4fc9bb6f329 100644
--- a/tools/testing/selftests/kvm/x86/hyperv_tlb_flush.c
+++ b/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);
diff --git a/tools/testing/selftests/kvm/x86/private_mem_conversions_test.c b/tools/testing/selftests/kvm/x86/private_mem_conversions_test.c
index e419b08f1fa6..3aa0673f79f3 100644
--- a/tools/testing/selftests/kvm/x86/private_mem_conversions_test.c
+++ b/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);
 
diff --git a/tools/testing/selftests/kvm/x86/private_mem_kvm_exits_test.c b/tools/testing/selftests/kvm/x86/private_mem_kvm_exits_test.c
index e26524fb4b50..e6d16e9d6120 100644
--- a/tools/testing/selftests/kvm/x86/private_mem_kvm_exits_test.c
+++ b/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);
diff --git a/tools/testing/selftests/kvm/x86/recalc_apic_map_test.c b/tools/testing/selftests/kvm/x86/recalc_apic_map_test.c
index 13abb65620d5..e3e397f32bff 100644
--- a/tools/testing/selftests/kvm/x86/recalc_apic_map_test.c
+++ b/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);
 
diff --git a/tools/testing/selftests/kvm/x86/sev_migrate_tests.c b/tools/testing/selftests/kvm/x86/sev_migrate_tests.c
index 16b7d830e686..179d684844ef 100644
--- a/tools/testing/selftests/kvm/x86/sev_migrate_tests.c
+++ b/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);
 }
diff --git a/tools/testing/selftests/kvm/x86/sync_regs_test.c b/tools/testing/selftests/kvm/x86/sync_regs_test.c
index f7228af7d594..99a5bbeffc5d 100644
--- a/tools/testing/selftests/kvm/x86/sync_regs_test.c
+++ b/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);
 }
diff --git a/tools/testing/selftests/kvm/x86/tsc_scaling_sync.c b/tools/testing/selftests/kvm/x86/tsc_scaling_sync.c
index 54b4b8d06d3b..2a3a9bd8b338 100644
--- a/tools/testing/selftests/kvm/x86/tsc_scaling_sync.c
+++ b/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;
 	}
 
diff --git a/tools/testing/selftests/kvm/x86/xapic_ipi_test.c b/tools/testing/selftests/kvm/x86/xapic_ipi_test.c
index 744df39e2c93..34309e8ad10e 100644
--- a/tools/testing/selftests/kvm/x86/xapic_ipi_test.c
+++ b/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);
diff --git a/tools/testing/selftests/kvm/x86/xen_shinfo_test.c b/tools/testing/selftests/kvm/x86/xen_shinfo_test.c
index 20f518fe2450..3ec5e67b21ef 100644
--- a/tools/testing/selftests/kvm/x86/xen_shinfo_test.c
+++ b/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: