1 files changed, 290 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/arm64/psci_test.c b/tools/testing/selftests/kvm/arm64/psci_test.c
new file mode 100644
index 000000000000..ab491ee9e5f7
--- /dev/null
+++ b/tools/testing/selftests/kvm/arm64/psci_test.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * psci_test - Tests relating to KVM's PSCI implementation.
+ *
+ * Copyright (c) 2021 Google LLC.
+ *
+ * This test includes:
+ *  - A regression test for a race between KVM servicing the PSCI CPU_ON call
+ *    and userspace reading the targeted vCPU's registers.
+ *  - A test for KVM's handling of PSCI SYSTEM_SUSPEND and the associated
+ *    KVM_SYSTEM_EVENT_SUSPEND UAPI.
+ */
+
+#include <linux/kernel.h>
+#include <linux/psci.h>
+#include <asm/cputype.h>
+
+#include "kvm_util.h"
+#include "processor.h"
+#include "test_util.h"
+
+#define CPU_ON_ENTRY_ADDR 0xfeedf00dul
+#define CPU_ON_CONTEXT_ID 0xdeadc0deul
+
+static uint64_t psci_cpu_on(uint64_t target_cpu, uint64_t entry_addr,
+			    uint64_t context_id)
+{
+	struct arm_smccc_res res;
+
+	smccc_hvc(PSCI_0_2_FN64_CPU_ON, target_cpu, entry_addr, context_id,
+		  0, 0, 0, 0, &res);
+
+	return res.a0;
+}
+
+static uint64_t psci_affinity_info(uint64_t target_affinity,
+				   uint64_t lowest_affinity_level)
+{
+	struct arm_smccc_res res;
+
+	smccc_hvc(PSCI_0_2_FN64_AFFINITY_INFO, target_affinity, lowest_affinity_level,
+		  0, 0, 0, 0, 0, &res);
+
+	return res.a0;
+}
+
+static uint64_t psci_system_suspend(uint64_t entry_addr, uint64_t context_id)
+{
+	struct arm_smccc_res res;
+
+	smccc_hvc(PSCI_1_0_FN64_SYSTEM_SUSPEND, entry_addr, context_id,
+		  0, 0, 0, 0, 0, &res);
+
+	return res.a0;
+}
+
+static uint64_t psci_system_off2(uint64_t type, uint64_t cookie)
+{
+	struct arm_smccc_res res;
+
+	smccc_hvc(PSCI_1_3_FN64_SYSTEM_OFF2, type, cookie, 0, 0, 0, 0, 0, &res);
+
+	return res.a0;
+}
+
+static uint64_t psci_features(uint32_t func_id)
+{
+	struct arm_smccc_res res;
+
+	smccc_hvc(PSCI_1_0_FN_PSCI_FEATURES, func_id, 0, 0, 0, 0, 0, 0, &res);
+
+	return res.a0;
+}
+
+static void vcpu_power_off(struct kvm_vcpu *vcpu)
+{
+	struct kvm_mp_state mp_state = {
+		.mp_state = KVM_MP_STATE_STOPPED,
+	};
+
+	vcpu_mp_state_set(vcpu, &mp_state);
+}
+
+static struct kvm_vm *setup_vm(void *guest_code, struct kvm_vcpu **source,
+			       struct kvm_vcpu **target)
+{
+	struct kvm_vcpu_init init;
+	struct kvm_vm *vm;
+
+	vm = vm_create(2);
+
+	vm_ioctl(vm, KVM_ARM_PREFERRED_TARGET, &init);
+	init.features[0] |= (1 << KVM_ARM_VCPU_PSCI_0_2);
+
+	*source = aarch64_vcpu_add(vm, 0, &init, guest_code);
+	*target = aarch64_vcpu_add(vm, 1, &init, guest_code);
+
+	return vm;
+}
+
+static void enter_guest(struct kvm_vcpu *vcpu)
+{
+	struct ucall uc;
+
+	vcpu_run(vcpu);
+	if (get_ucall(vcpu, &uc) == UCALL_ABORT)
+		REPORT_GUEST_ASSERT(uc);
+}
+
+static void assert_vcpu_reset(struct kvm_vcpu *vcpu)
+{
+	uint64_t obs_pc, obs_x0;
+
+	obs_pc = vcpu_get_reg(vcpu, ARM64_CORE_REG(regs.pc));
+	obs_x0 = vcpu_get_reg(vcpu, ARM64_CORE_REG(regs.regs[0]));
+
+	TEST_ASSERT(obs_pc == CPU_ON_ENTRY_ADDR,
+		    "unexpected target cpu pc: %lx (expected: %lx)",
+		    obs_pc, CPU_ON_ENTRY_ADDR);
+	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)
+{
+	struct kvm_vcpu *source, *target;
+	uint64_t target_mpidr;
+	struct kvm_vm *vm;
+	struct ucall uc;
+
+	vm = setup_vm(guest_test_cpu_on, &source, &target);
+
+	/*
+	 * make sure the target is already off when executing the test.
+	 */
+	vcpu_power_off(target);
+
+	target_mpidr = vcpu_get_reg(target, KVM_ARM64_SYS_REG(SYS_MPIDR_EL1));
+	vcpu_args_set(source, 1, target_mpidr & MPIDR_HWID_BITMASK);
+	enter_guest(source);
+
+	if (get_ucall(source, &uc) != UCALL_DONE)
+		TEST_FAIL("Unhandled ucall: %lu", uc.cmd);
+
+	assert_vcpu_reset(target);
+	kvm_vm_free(vm);
+}
+
+static void guest_test_system_suspend(void)
+{
+	uint64_t ret;
+
+	/* assert that SYSTEM_SUSPEND is discoverable */
+	GUEST_ASSERT(!psci_features(PSCI_1_0_FN_SYSTEM_SUSPEND));
+	GUEST_ASSERT(!psci_features(PSCI_1_0_FN64_SYSTEM_SUSPEND));
+
+	ret = psci_system_suspend(CPU_ON_ENTRY_ADDR, CPU_ON_CONTEXT_ID);
+	GUEST_SYNC(ret);
+}
+
+static void host_test_system_suspend(void)
+{
+	struct kvm_vcpu *source, *target;
+	struct kvm_run *run;
+	struct kvm_vm *vm;
+
+	vm = setup_vm(guest_test_system_suspend, &source, &target);
+	vm_enable_cap(vm, KVM_CAP_ARM_SYSTEM_SUSPEND, 0);
+
+	vcpu_power_off(target);
+	run = source->run;
+
+	enter_guest(source);
+
+	TEST_ASSERT_KVM_EXIT_REASON(source, KVM_EXIT_SYSTEM_EVENT);
+	TEST_ASSERT(run->system_event.type == KVM_SYSTEM_EVENT_SUSPEND,
+		    "Unhandled system event: %u (expected: %u)",
+		    run->system_event.type, KVM_SYSTEM_EVENT_SUSPEND);
+
+	kvm_vm_free(vm);
+}
+
+static void guest_test_system_off2(void)
+{
+	uint64_t ret;
+
+	/* assert that SYSTEM_OFF2 is discoverable */
+	GUEST_ASSERT(psci_features(PSCI_1_3_FN_SYSTEM_OFF2) &
+		     PSCI_1_3_OFF_TYPE_HIBERNATE_OFF);
+	GUEST_ASSERT(psci_features(PSCI_1_3_FN64_SYSTEM_OFF2) &
+		     PSCI_1_3_OFF_TYPE_HIBERNATE_OFF);
+
+	/* With non-zero 'cookie' field, it should fail */
+	ret = psci_system_off2(PSCI_1_3_OFF_TYPE_HIBERNATE_OFF, 1);
+	GUEST_ASSERT(ret == PSCI_RET_INVALID_PARAMS);
+
+	/*
+	 * This would normally never return, so KVM sets the return value
+	 * to PSCI_RET_INTERNAL_FAILURE. The test case *does* return, so
+	 * that it can test both values for HIBERNATE_OFF.
+	 */
+	ret = psci_system_off2(PSCI_1_3_OFF_TYPE_HIBERNATE_OFF, 0);
+	GUEST_ASSERT(ret == PSCI_RET_INTERNAL_FAILURE);
+
+	/*
+	 * Revision F.b of the PSCI v1.3 specification documents zero as an
+	 * alias for HIBERNATE_OFF, since that's the value used in earlier
+	 * revisions of the spec and some implementations in the field.
+	 */
+	ret = psci_system_off2(0, 1);
+	GUEST_ASSERT(ret == PSCI_RET_INVALID_PARAMS);
+
+	ret = psci_system_off2(0, 0);
+	GUEST_ASSERT(ret == PSCI_RET_INTERNAL_FAILURE);
+
+	GUEST_DONE();
+}
+
+static void host_test_system_off2(void)
+{
+	struct kvm_vcpu *source, *target;
+	struct kvm_mp_state mps;
+	uint64_t psci_version = 0;
+	int nr_shutdowns = 0;
+	struct kvm_run *run;
+	struct ucall uc;
+
+	setup_vm(guest_test_system_off2, &source, &target);
+
+	psci_version = vcpu_get_reg(target, KVM_REG_ARM_PSCI_VERSION);
+
+	TEST_ASSERT(psci_version >= PSCI_VERSION(1, 3),
+		    "Unexpected PSCI version %lu.%lu",
+		    PSCI_VERSION_MAJOR(psci_version),
+		    PSCI_VERSION_MINOR(psci_version));
+
+	vcpu_power_off(target);
+	run = source->run;
+
+	enter_guest(source);
+	while (run->exit_reason == KVM_EXIT_SYSTEM_EVENT) {
+		TEST_ASSERT(run->system_event.type == KVM_SYSTEM_EVENT_SHUTDOWN,
+			    "Unhandled system event: %u (expected: %u)",
+			    run->system_event.type, KVM_SYSTEM_EVENT_SHUTDOWN);
+		TEST_ASSERT(run->system_event.ndata >= 1,
+			    "Unexpected amount of system event data: %u (expected, >= 1)",
+			    run->system_event.ndata);
+		TEST_ASSERT(run->system_event.data[0] & KVM_SYSTEM_EVENT_SHUTDOWN_FLAG_PSCI_OFF2,
+			    "PSCI_OFF2 flag not set. Flags %llu (expected %llu)",
+			    run->system_event.data[0], KVM_SYSTEM_EVENT_SHUTDOWN_FLAG_PSCI_OFF2);
+
+		nr_shutdowns++;
+
+		/* Restart the vCPU */
+	        mps.mp_state = KVM_MP_STATE_RUNNABLE;
+		vcpu_mp_state_set(source, &mps);
+
+		enter_guest(source);
+	}
+
+	TEST_ASSERT(get_ucall(source, &uc) == UCALL_DONE, "Guest did not exit cleanly");
+	TEST_ASSERT(nr_shutdowns == 2, "Two shutdown events were expected, but saw %d", nr_shutdowns);
+}
+
+int main(void)
+{
+	TEST_REQUIRE(kvm_has_cap(KVM_CAP_ARM_SYSTEM_SUSPEND));
+
+	host_test_cpu_on();
+	host_test_system_suspend();
+	host_test_system_off2();
+	return 0;
+}