1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * psci_cpu_on_test - Test that the observable state of a vCPU targeted by the 4 * CPU_ON PSCI call matches what the caller requested. 5 * 6 * Copyright (c) 2021 Google LLC. 7 * 8 * This is a regression test for a race between KVM servicing the PSCI call and 9 * userspace reading the vCPUs registers. 10 */ 11 12 #define _GNU_SOURCE 13 14 #include <linux/psci.h> 15 16 #include "kvm_util.h" 17 #include "processor.h" 18 #include "test_util.h" 19 20 #define VCPU_ID_SOURCE 0 21 #define VCPU_ID_TARGET 1 22 23 #define CPU_ON_ENTRY_ADDR 0xfeedf00dul 24 #define CPU_ON_CONTEXT_ID 0xdeadc0deul 25 26 static uint64_t psci_cpu_on(uint64_t target_cpu, uint64_t entry_addr, 27 uint64_t context_id) 28 { 29 register uint64_t x0 asm("x0") = PSCI_0_2_FN64_CPU_ON; 30 register uint64_t x1 asm("x1") = target_cpu; 31 register uint64_t x2 asm("x2") = entry_addr; 32 register uint64_t x3 asm("x3") = context_id; 33 34 asm("hvc #0" 35 : "=r"(x0) 36 : "r"(x0), "r"(x1), "r"(x2), "r"(x3) 37 : "memory"); 38 39 return x0; 40 } 41 42 static uint64_t psci_affinity_info(uint64_t target_affinity, 43 uint64_t lowest_affinity_level) 44 { 45 register uint64_t x0 asm("x0") = PSCI_0_2_FN64_AFFINITY_INFO; 46 register uint64_t x1 asm("x1") = target_affinity; 47 register uint64_t x2 asm("x2") = lowest_affinity_level; 48 49 asm("hvc #0" 50 : "=r"(x0) 51 : "r"(x0), "r"(x1), "r"(x2) 52 : "memory"); 53 54 return x0; 55 } 56 57 static void guest_main(uint64_t target_cpu) 58 { 59 GUEST_ASSERT(!psci_cpu_on(target_cpu, CPU_ON_ENTRY_ADDR, CPU_ON_CONTEXT_ID)); 60 uint64_t target_state; 61 62 do { 63 target_state = psci_affinity_info(target_cpu, 0); 64 65 GUEST_ASSERT((target_state == PSCI_0_2_AFFINITY_LEVEL_ON) || 66 (target_state == PSCI_0_2_AFFINITY_LEVEL_OFF)); 67 } while (target_state != PSCI_0_2_AFFINITY_LEVEL_ON); 68 69 GUEST_DONE(); 70 } 71 72 int main(void) 73 { 74 uint64_t target_mpidr, obs_pc, obs_x0; 75 struct kvm_vcpu_init init; 76 struct kvm_vm *vm; 77 struct ucall uc; 78 79 vm = vm_create(VM_MODE_DEFAULT, DEFAULT_GUEST_PHY_PAGES, O_RDWR); 80 kvm_vm_elf_load(vm, program_invocation_name); 81 ucall_init(vm, NULL); 82 83 vm_ioctl(vm, KVM_ARM_PREFERRED_TARGET, &init); 84 init.features[0] |= (1 << KVM_ARM_VCPU_PSCI_0_2); 85 86 aarch64_vcpu_add_default(vm, VCPU_ID_SOURCE, &init, guest_main); 87 88 /* 89 * make sure the target is already off when executing the test. 90 */ 91 init.features[0] |= (1 << KVM_ARM_VCPU_POWER_OFF); 92 aarch64_vcpu_add_default(vm, VCPU_ID_TARGET, &init, guest_main); 93 94 get_reg(vm, VCPU_ID_TARGET, KVM_ARM64_SYS_REG(SYS_MPIDR_EL1), &target_mpidr); 95 vcpu_args_set(vm, VCPU_ID_SOURCE, 1, target_mpidr & MPIDR_HWID_BITMASK); 96 vcpu_run(vm, VCPU_ID_SOURCE); 97 98 switch (get_ucall(vm, VCPU_ID_SOURCE, &uc)) { 99 case UCALL_DONE: 100 break; 101 case UCALL_ABORT: 102 TEST_FAIL("%s at %s:%ld", (const char *)uc.args[0], __FILE__, 103 uc.args[1]); 104 break; 105 default: 106 TEST_FAIL("Unhandled ucall: %lu", uc.cmd); 107 } 108 109 get_reg(vm, VCPU_ID_TARGET, ARM64_CORE_REG(regs.pc), &obs_pc); 110 get_reg(vm, VCPU_ID_TARGET, ARM64_CORE_REG(regs.regs[0]), &obs_x0); 111 112 TEST_ASSERT(obs_pc == CPU_ON_ENTRY_ADDR, 113 "unexpected target cpu pc: %lx (expected: %lx)", 114 obs_pc, CPU_ON_ENTRY_ADDR); 115 TEST_ASSERT(obs_x0 == CPU_ON_CONTEXT_ID, 116 "unexpected target context id: %lx (expected: %lx)", 117 obs_x0, CPU_ON_CONTEXT_ID); 118 119 kvm_vm_free(vm); 120 return 0; 121 } 122