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 void self_smi(void)
  57 {
  58         x2apic_write_reg(APIC_ICR,
  59                          APIC_DEST_SELF | APIC_INT_ASSERT | APIC_DM_SMI);
  60 }
  61
  62 void guest_code(void *arg)
  63 {
  64         uint64_t apicbase = rdmsr(MSR_IA32_APICBASE);
  65
  66         sync_with_host(1);
  67
  68         wrmsr(MSR_IA32_APICBASE, apicbase | X2APIC_ENABLE);
  69
  70         sync_with_host(2);
  71
  72         self_smi();
  73
  74         sync_with_host(4);
  75
  76         if (arg) {
  77                 if (cpu_has_svm())
  78                         generic_svm_setup(arg, NULL, NULL);
  79                 else
  80                         GUEST_ASSERT(prepare_for_vmx_operation(arg));
  81
  82                 sync_with_host(5);
  83
  84                 self_smi();
  85
  86                 sync_with_host(7);
  87         }
  88
  89         sync_with_host(DONE);
  90 }
  91
  92 int main(int argc, char *argv[])
  93 {
  94         vm_vaddr_t nested_gva = 0;
  95
  96         struct kvm_regs regs;
  97         struct kvm_vm *vm;
  98         struct kvm_run *run;
  99         struct kvm_x86_state *state;
 100         int stage, stage_reported;
 101
 102         /* Create VM */
 103         vm = vm_create_default(VCPU_ID, 0, guest_code);
 104
 105         run = vcpu_state(vm, VCPU_ID);
 106
 107         vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, SMRAM_GPA,
 108                                     SMRAM_MEMSLOT, SMRAM_PAGES, 0);
 109         TEST_ASSERT(vm_phy_pages_alloc(vm, SMRAM_PAGES, SMRAM_GPA, SMRAM_MEMSLOT)
 110                     == SMRAM_GPA, "could not allocate guest physical addresses?");
 111
 112         memset(addr_gpa2hva(vm, SMRAM_GPA), 0x0, SMRAM_SIZE);
 113         memcpy(addr_gpa2hva(vm, SMRAM_GPA) + 0x8000, smi_handler,
 114                sizeof(smi_handler));
 115
 116         vcpu_set_msr(vm, VCPU_ID, MSR_IA32_SMBASE, SMRAM_GPA);
 117
 118         if (kvm_check_cap(KVM_CAP_NESTED_STATE)) {
 119                 if (nested_svm_supported())
 120                         vcpu_alloc_svm(vm, &nested_gva);
 121                 else if (nested_vmx_supported())
 122                         vcpu_alloc_vmx(vm, &nested_gva);
 123         }
 124
 125         if (!nested_gva)
 126                 pr_info("will skip SMM test with VMX enabled\n");
 127
 128         vcpu_args_set(vm, VCPU_ID, 1, nested_gva);
 129
 130         for (stage = 1;; stage++) {
 131                 _vcpu_run(vm, VCPU_ID);
 132                 TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
 133                             "Stage %d: unexpected exit reason: %u (%s),\n",
 134                             stage, run->exit_reason,
 135                             exit_reason_str(run->exit_reason));
 136
 137                 memset(&regs, 0, sizeof(regs));
 138                 vcpu_regs_get(vm, VCPU_ID, &regs);
 139
 140                 stage_reported = regs.rax & 0xff;
 141
 142                 if (stage_reported == DONE)
 143                         goto done;
 144
 145                 TEST_ASSERT(stage_reported == stage ||
 146                             stage_reported == SMRAM_STAGE,
 147                             "Unexpected stage: #%x, got %x",
 148                             stage, stage_reported);
 149
 150                 state = vcpu_save_state(vm, VCPU_ID);
 151                 kvm_vm_release(vm);
 152                 kvm_vm_restart(vm, O_RDWR);
 153                 vm_vcpu_add(vm, VCPU_ID);
 154                 vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
 155                 vcpu_load_state(vm, VCPU_ID, state);
 156                 run = vcpu_state(vm, VCPU_ID);
 157                 free(state);
 158         }
 159
 160 done:
 161         kvm_vm_free(vm);
 162 }