KVM: selftests: Convert arch_timer tests to common helpers to pin task

Convert the arch timer tests to use __pin_task_to_cpu() and
pin_self_to_cpu().

No functional change intended.

Link: https://lore.kernel.org/r/20250626001225.744268-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: sean-jc

tools/testing/selftests/kvm/arch_timer.c

@@ -98,16 +98,11 @@ static uint32_t test_get_pcpu(void)
 static int test_migrate_vcpu(unsigned int vcpu_idx)
 {
 	int ret;
-	cpu_set_t cpuset;
 	uint32_t new_pcpu = test_get_pcpu();
 
-	CPU_ZERO(&cpuset);
-	CPU_SET(new_pcpu, &cpuset);
-
 	pr_debug("Migrating vCPU: %u to pCPU: %u\n", vcpu_idx, new_pcpu);
 
-	ret = pthread_setaffinity_np(pt_vcpu_run[vcpu_idx],
-				     sizeof(cpuset), &cpuset);
+	ret = __pin_task_to_cpu(pt_vcpu_run[vcpu_idx], new_pcpu);
 
 	/* Allow the error where the vCPU thread is already finished */
 	TEST_ASSERT(ret == 0 || ret == ESRCH,

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

@@ -862,25 +862,6 @@ static uint32_t next_pcpu(void)
 	return next;
 }
 
-static void migrate_self(uint32_t new_pcpu)
-{
-	int ret;
-	cpu_set_t cpuset;
-	pthread_t thread;
-
-	thread = pthread_self();
-
-	CPU_ZERO(&cpuset);
-	CPU_SET(new_pcpu, &cpuset);
-
-	pr_debug("Migrating from %u to %u\n", sched_getcpu(), new_pcpu);
-
-	ret = pthread_setaffinity_np(thread, sizeof(cpuset), &cpuset);
-
-	TEST_ASSERT(ret == 0, "Failed to migrate to pCPU: %u; ret: %d\n",
-		    new_pcpu, ret);
-}
-
 static void kvm_set_cntxct(struct kvm_vcpu *vcpu, uint64_t cnt,
 			   enum arch_timer timer)
 {
@@ -907,7 +888,7 @@ static void handle_sync(struct kvm_vcpu *vcpu, struct ucall *uc)
 		sched_yield();
 		break;
 	case USERSPACE_MIGRATE_SELF:
-		migrate_self(next_pcpu());
+		pin_self_to_cpu(next_pcpu());
 		break;
 	default:
 		break;
@@ -919,7 +900,7 @@ static void test_run(struct kvm_vm *vm, struct kvm_vcpu *vcpu)
 	struct ucall uc;
 
 	/* Start on CPU 0 */
-	migrate_self(0);
+	pin_self_to_cpu(0);
 
 	while (true) {
 		vcpu_run(vcpu);