Quelle  psci_test.c   Sprache: C

// 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;
}