selftests: KVM: Refactor psci_test to make it amenable to new tests

Split up the current test into several helpers that will be useful to
subsequent test cases added to the PSCI test suite.
Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220504032446.4133305-12-oupton@google.com

tools/testing/selftests/kvm/aarch64/psci_test.c

@@ -45,21 +45,6 @@ static uint64_t psci_affinity_info(uint64_t target_affinity,
 	return res.a0;
 }
 
-static void guest_main(uint64_t target_cpu)
-{
-	GUEST_ASSERT(!psci_cpu_on(target_cpu, CPU_ON_ENTRY_ADDR, CPU_ON_CONTEXT_ID));
-	uint64_t target_state;
-
-	do {
-		target_state = psci_affinity_info(target_cpu, 0);
-
-		GUEST_ASSERT((target_state == PSCI_0_2_AFFINITY_LEVEL_ON) ||
-			     (target_state == PSCI_0_2_AFFINITY_LEVEL_OFF));
-	} while (target_state != PSCI_0_2_AFFINITY_LEVEL_ON);
-
-	GUEST_DONE();
-}
-
 static void vcpu_power_off(struct kvm_vm *vm, uint32_t vcpuid)
 {
 	struct kvm_mp_state mp_state = {
@@ -69,12 +54,10 @@ static void vcpu_power_off(struct kvm_vm *vm, uint32_t vcpuid)
 	vcpu_set_mp_state(vm, vcpuid, &mp_state);
 }
 
-int main(void)
+static struct kvm_vm *setup_vm(void *guest_code)
 {
-	uint64_t target_mpidr, obs_pc, obs_x0;
 	struct kvm_vcpu_init init;
 	struct kvm_vm *vm;
-	struct ucall uc;
 
 	vm = vm_create(VM_MODE_DEFAULT, DEFAULT_GUEST_PHY_PAGES, O_RDWR);
 	kvm_vm_elf_load(vm, program_invocation_name);
@@ -83,31 +66,28 @@ int main(void)
 	vm_ioctl(vm, KVM_ARM_PREFERRED_TARGET, &init);
 	init.features[0] |= (1 << KVM_ARM_VCPU_PSCI_0_2);
 
-	aarch64_vcpu_add_default(vm, VCPU_ID_SOURCE, &init, guest_main);
-	aarch64_vcpu_add_default(vm, VCPU_ID_TARGET, &init, guest_main);
+	aarch64_vcpu_add_default(vm, VCPU_ID_SOURCE, &init, guest_code);
+	aarch64_vcpu_add_default(vm, VCPU_ID_TARGET, &init, guest_code);
 
-	/*
-	 * make sure the target is already off when executing the test.
-	 */
-	vcpu_power_off(vm, VCPU_ID_TARGET);
+	return vm;
+}
 
-	get_reg(vm, VCPU_ID_TARGET, KVM_ARM64_SYS_REG(SYS_MPIDR_EL1), &target_mpidr);
-	vcpu_args_set(vm, VCPU_ID_SOURCE, 1, target_mpidr & MPIDR_HWID_BITMASK);
-	vcpu_run(vm, VCPU_ID_SOURCE);
+static void enter_guest(struct kvm_vm *vm, uint32_t vcpuid)
+{
+	struct ucall uc;
 
-	switch (get_ucall(vm, VCPU_ID_SOURCE, &uc)) {
-	case UCALL_DONE:
-		break;
-	case UCALL_ABORT:
+	vcpu_run(vm, vcpuid);
+	if (get_ucall(vm, vcpuid, &uc) == UCALL_ABORT)
 		TEST_FAIL("%s at %s:%ld", (const char *)uc.args[0], __FILE__,
 			  uc.args[1]);
-		break;
-	default:
-		TEST_FAIL("Unhandled ucall: %lu", uc.cmd);
-	}
+}
+
+static void assert_vcpu_reset(struct kvm_vm *vm, uint32_t vcpuid)
+{
+	uint64_t obs_pc, obs_x0;
 
-	get_reg(vm, VCPU_ID_TARGET, ARM64_CORE_REG(regs.pc), &obs_pc);
-	get_reg(vm, VCPU_ID_TARGET, ARM64_CORE_REG(regs.regs[0]), &obs_x0);
+	get_reg(vm, vcpuid, ARM64_CORE_REG(regs.pc), &obs_pc);
+	get_reg(vm, vcpuid, ARM64_CORE_REG(regs.regs[0]), &obs_x0);
 
 	TEST_ASSERT(obs_pc == CPU_ON_ENTRY_ADDR,
 		    "unexpected target cpu pc: %lx (expected: %lx)",
@@ -115,7 +95,50 @@ int main(void)
 	TEST_ASSERT(obs_x0 == CPU_ON_CONTEXT_ID,
 		    "unexpected target context id: %lx (expected: %lx)",
 		    obs_x0, CPU_ON_CONTEXT_ID);
+}
+
+static void guest_test_cpu_on(uint64_t target_cpu)
+{
+	uint64_t target_state;
+
+	GUEST_ASSERT(!psci_cpu_on(target_cpu, CPU_ON_ENTRY_ADDR, CPU_ON_CONTEXT_ID));
+
+	do {
+		target_state = psci_affinity_info(target_cpu, 0);
+
+		GUEST_ASSERT((target_state == PSCI_0_2_AFFINITY_LEVEL_ON) ||
+			     (target_state == PSCI_0_2_AFFINITY_LEVEL_OFF));
+	} while (target_state != PSCI_0_2_AFFINITY_LEVEL_ON);
+
+	GUEST_DONE();
+}
+
+static void host_test_cpu_on(void)
+{
+	uint64_t target_mpidr;
+	struct kvm_vm *vm;
+	struct ucall uc;
+
+	vm = setup_vm(guest_test_cpu_on);
+
+	/*
+	 * make sure the target is already off when executing the test.
+	 */
+	vcpu_power_off(vm, VCPU_ID_TARGET);
+
+	get_reg(vm, VCPU_ID_TARGET, KVM_ARM64_SYS_REG(SYS_MPIDR_EL1), &target_mpidr);
+	vcpu_args_set(vm, VCPU_ID_SOURCE, 1, target_mpidr & MPIDR_HWID_BITMASK);
+	enter_guest(vm, VCPU_ID_SOURCE);
+
+	if (get_ucall(vm, VCPU_ID_SOURCE, &uc) != UCALL_DONE)
+		TEST_FAIL("Unhandled ucall: %lu", uc.cmd);
 
+	assert_vcpu_reset(vm, VCPU_ID_TARGET);
 	kvm_vm_free(vm);
+}
+
+int main(void)
+{
+	host_test_cpu_on();
 	return 0;
 }