tools/testing/selftests/kvm/x86_64/smm_test.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2018, Red Hat, Inc.
   4  *
   5  * Tests for SMM.
   6  */
   7 #define _GNU_SOURCE /* for program_invocation_short_name */
   8 #include <fcntl.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <stdint.h>
  12 #include <string.h>
  13 #include <sys/ioctl.h>
  14
  15 #include "test_util.h"
  16
  17 #include "kvm_util.h"
  18
  19 #include "vmx.h"
  20 #include "svm_util.h"
  21
  22 #define VCPU_ID       1
  23
  24 #define PAGE_SIZE  4096
  25
  26 #define SMRAM_SIZE 65536
  27 #define SMRAM_MEMSLOT ((1 << 16) | 1)
  28 #define SMRAM_PAGES (SMRAM_SIZE / PAGE_SIZE)
  29 #define SMRAM_GPA 0x1000000
  30 #define SMRAM_STAGE 0xfe
  31
  32 #define STR(x) #x
  33 #define XSTR(s) STR(s)
  34
  35 #define SYNC_PORT 0xe
  36 #define DONE 0xff
  37
  38 /*
  39  * This is compiled as normal 64-bit code, however, SMI handler is executed
  40  * in real-address mode. To stay simple we're limiting ourselves to a mode
  41  * independent subset of asm here.
  42  * SMI handler always report back fixed stage SMRAM_STAGE.
  43  */
  44 uint8_t smi_handler[] = {
  45         0xb0, SMRAM_STAGE,    /* mov $SMRAM_STAGE, %al */
  46         0xe4, SYNC_PORT,      /* in $SYNC_PORT, %al */
  47         0x0f, 0xaa,           /* rsm */
  48 };
  49
  50 static inline void sync_with_host(uint64_t phase)
  51 {
  52         asm volatile("in $" XSTR(SYNC_PORT)", %%al \n"
  53                      : "+a" (phase));
  54 }
  55
  56 static void self_smi(void)
  57 {
  58         x2apic_write_reg(APIC_ICR,
  59                          APIC_DEST_SELF | APIC_INT_ASSERT | APIC_DM_SMI);
  60 }
  61
  62 static void l2_guest_code(void)
  63 {
  64         sync_with_host(8);
  65
  66         sync_with_host(10);
  67
  68         vmcall();
  69 }
  70
  71 static void guest_code(void *arg)
  72 {
  73         #define L2_GUEST_STACK_SIZE 64
  74         unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
  75         uint64_t apicbase = rdmsr(MSR_IA32_APICBASE);
  76         struct svm_test_data *svm = arg;
  77         struct vmx_pages *vmx_pages = arg;
  78
  79         sync_with_host(1);
  80
  81         wrmsr(MSR_IA32_APICBASE, apicbase | X2APIC_ENABLE);
  82
  83         sync_with_host(2);
  84
  85         self_smi();
  86
  87         sync_with_host(4);
  88
  89         if (arg) {
  90                 if (cpu_has_svm()) {
  91                         generic_svm_setup(svm, l2_guest_code,
  92                                           &l2_guest_stack[L2_GUEST_STACK_SIZE]);
  93                 } else {
  94                         GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
  95                         GUEST_ASSERT(load_vmcs(vmx_pages));
  96                         prepare_vmcs(vmx_pages, l2_guest_code,
  97                                      &l2_guest_stack[L2_GUEST_STACK_SIZE]);
  98                 }
  99
 100                 sync_with_host(5);
 101
 102                 self_smi();
 103
 104                 sync_with_host(7);
 105
 106                 if (cpu_has_svm()) {
 107                         run_guest(svm->vmcb, svm->vmcb_gpa);
 108                         run_guest(svm->vmcb, svm->vmcb_gpa);
 109                 } else {
 110                         vmlaunch();
 111                         vmresume();
 112                 }
 113
 114                 /* Stages 8-11 are eaten by SMM (SMRAM_STAGE reported instead) */
 115                 sync_with_host(12);
 116         }
 117
 118         sync_with_host(DONE);
 119 }
 120
 121 void inject_smi(struct kvm_vm *vm)
 122 {
 123         struct kvm_vcpu_events events;
 124
 125         vcpu_events_get(vm, VCPU_ID, &events);
 126
 127         events.smi.pending = 1;
 128         events.flags |= KVM_VCPUEVENT_VALID_SMM;
 129
 130         vcpu_events_set(vm, VCPU_ID, &events);
 131 }
 132
 133 int main(int argc, char *argv[])
 134 {
 135         vm_vaddr_t nested_gva = 0;
 136
 137         struct kvm_regs regs;
 138         struct kvm_vm *vm;
 139         struct kvm_run *run;
 140         struct kvm_x86_state *state;
 141         int stage, stage_reported;
 142
 143         /* Create VM */
 144         vm = vm_create_default(VCPU_ID, 0, guest_code);
 145
 146         run = vcpu_state(vm, VCPU_ID);
 147
 148         vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, SMRAM_GPA,
 149                                     SMRAM_MEMSLOT, SMRAM_PAGES, 0);
 150         TEST_ASSERT(vm_phy_pages_alloc(vm, SMRAM_PAGES, SMRAM_GPA, SMRAM_MEMSLOT)
 151                     == SMRAM_GPA, "could not allocate guest physical addresses?");
 152
 153         memset(addr_gpa2hva(vm, SMRAM_GPA), 0x0, SMRAM_SIZE);
 154         memcpy(addr_gpa2hva(vm, SMRAM_GPA) + 0x8000, smi_handler,
 155                sizeof(smi_handler));
 156
 157         vcpu_set_msr(vm, VCPU_ID, MSR_IA32_SMBASE, SMRAM_GPA);
 158
 159         if (kvm_check_cap(KVM_CAP_NESTED_STATE)) {
 160                 if (nested_svm_supported())
 161                         vcpu_alloc_svm(vm, &nested_gva);
 162                 else if (nested_vmx_supported())
 163                         vcpu_alloc_vmx(vm, &nested_gva);
 164         }
 165
 166         if (!nested_gva)
 167                 pr_info("will skip SMM test with VMX enabled\n");
 168
 169         vcpu_args_set(vm, VCPU_ID, 1, nested_gva);
 170
 171         for (stage = 1;; stage++) {
 172                 _vcpu_run(vm, VCPU_ID);
 173                 TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
 174                             "Stage %d: unexpected exit reason: %u (%s),\n",
 175                             stage, run->exit_reason,
 176                             exit_reason_str(run->exit_reason));
 177
 178                 memset(&regs, 0, sizeof(regs));
 179                 vcpu_regs_get(vm, VCPU_ID, &regs);
 180
 181                 stage_reported = regs.rax & 0xff;
 182
 183                 if (stage_reported == DONE)
 184                         goto done;
 185
 186                 TEST_ASSERT(stage_reported == stage ||
 187                             stage_reported == SMRAM_STAGE,
 188                             "Unexpected stage: #%x, got %x",
 189                             stage, stage_reported);
 190
 191                 /*
 192                  * Enter SMM during L2 execution and check that we correctly
 193                  * return from it. Do not perform save/restore while in SMM yet.
 194                  */
 195                 if (stage == 8) {
 196                         inject_smi(vm);
 197                         continue;
 198                 }
 199
 200                 /*
 201                  * Perform save/restore while the guest is in SMM triggered
 202                  * during L2 execution.
 203                  */
 204                 if (stage == 10)
 205                         inject_smi(vm);
 206
 207                 state = vcpu_save_state(vm, VCPU_ID);
 208                 kvm_vm_release(vm);
 209                 kvm_vm_restart(vm, O_RDWR);
 210                 vm_vcpu_add(vm, VCPU_ID);
 211                 vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
 212                 vcpu_load_state(vm, VCPU_ID, state);
 213                 run = vcpu_state(vm, VCPU_ID);
 214                 kvm_x86_state_cleanup(state);
 215         }
 216
 217 done:
 218         kvm_vm_free(vm);
 219 }