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 #include <fcntl.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <stdint.h>
  11 #include <string.h>
  12 #include <sys/ioctl.h>
  13
  14 #include "test_util.h"
  15
  16 #include "kvm_util.h"
  17
  18 #include "vmx.h"
  19 #include "svm_util.h"
  20
  21 #define SMRAM_SIZE 65536
  22 #define SMRAM_MEMSLOT ((1 << 16) | 1)
  23 #define SMRAM_PAGES (SMRAM_SIZE / PAGE_SIZE)
  24 #define SMRAM_GPA 0x1000000
  25 #define SMRAM_STAGE 0xfe
  26
  27 #define STR(x) #x
  28 #define XSTR(s) STR(s)
  29
  30 #define SYNC_PORT 0xe
  31 #define DONE 0xff
  32
  33 /*
  34  * This is compiled as normal 64-bit code, however, SMI handler is executed
  35  * in real-address mode. To stay simple we're limiting ourselves to a mode
  36  * independent subset of asm here.
  37  * SMI handler always report back fixed stage SMRAM_STAGE.
  38  */
  39 uint8_t smi_handler[] = {
  40         0xb0, SMRAM_STAGE,    /* mov $SMRAM_STAGE, %al */
  41         0xe4, SYNC_PORT,      /* in $SYNC_PORT, %al */
  42         0x0f, 0xaa,           /* rsm */
  43 };
  44
  45 static inline void sync_with_host(uint64_t phase)
  46 {
  47         asm volatile("in $" XSTR(SYNC_PORT)", %%al \n"
  48                      : "+a" (phase));
  49 }
  50
  51 static void self_smi(void)
  52 {
  53         x2apic_write_reg(APIC_ICR,
  54                          APIC_DEST_SELF | APIC_INT_ASSERT | APIC_DM_SMI);
  55 }
  56
  57 static void l2_guest_code(void)
  58 {
  59         sync_with_host(8);
  60
  61         sync_with_host(10);
  62
  63         vmcall();
  64 }
  65
  66 static void guest_code(void *arg)
  67 {
  68         #define L2_GUEST_STACK_SIZE 64
  69         unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
  70         uint64_t apicbase = rdmsr(MSR_IA32_APICBASE);
  71         struct svm_test_data *svm = arg;
  72         struct vmx_pages *vmx_pages = arg;
  73
  74         sync_with_host(1);
  75
  76         wrmsr(MSR_IA32_APICBASE, apicbase | X2APIC_ENABLE);
  77
  78         sync_with_host(2);
  79
  80         self_smi();
  81
  82         sync_with_host(4);
  83
  84         if (arg) {
  85                 if (this_cpu_has(X86_FEATURE_SVM)) {
  86                         generic_svm_setup(svm, l2_guest_code,
  87                                           &l2_guest_stack[L2_GUEST_STACK_SIZE]);
  88                 } else {
  89                         GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
  90                         GUEST_ASSERT(load_vmcs(vmx_pages));
  91                         prepare_vmcs(vmx_pages, l2_guest_code,
  92                                      &l2_guest_stack[L2_GUEST_STACK_SIZE]);
  93                 }
  94
  95                 sync_with_host(5);
  96
  97                 self_smi();
  98
  99                 sync_with_host(7);
 100
 101                 if (this_cpu_has(X86_FEATURE_SVM)) {
 102                         run_guest(svm->vmcb, svm->vmcb_gpa);
 103                         run_guest(svm->vmcb, svm->vmcb_gpa);
 104                 } else {
 105                         vmlaunch();
 106                         vmresume();
 107                 }
 108
 109                 /* Stages 8-11 are eaten by SMM (SMRAM_STAGE reported instead) */
 110                 sync_with_host(12);
 111         }
 112
 113         sync_with_host(DONE);
 114 }
 115
 116 void inject_smi(struct kvm_vcpu *vcpu)
 117 {
 118         struct kvm_vcpu_events events;
 119
 120         vcpu_events_get(vcpu, &events);
 121
 122         events.smi.pending = 1;
 123         events.flags |= KVM_VCPUEVENT_VALID_SMM;
 124
 125         vcpu_events_set(vcpu, &events);
 126 }
 127
 128 int main(int argc, char *argv[])
 129 {
 130         vm_vaddr_t nested_gva = 0;
 131
 132         struct kvm_vcpu *vcpu;
 133         struct kvm_regs regs;
 134         struct kvm_vm *vm;
 135         struct kvm_x86_state *state;
 136         int stage, stage_reported;
 137
 138         TEST_REQUIRE(kvm_has_cap(KVM_CAP_X86_SMM));
 139
 140         /* Create VM */
 141         vm = vm_create_with_one_vcpu(&vcpu, guest_code);
 142
 143         vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, SMRAM_GPA,
 144                                     SMRAM_MEMSLOT, SMRAM_PAGES, 0);
 145         TEST_ASSERT(vm_phy_pages_alloc(vm, SMRAM_PAGES, SMRAM_GPA, SMRAM_MEMSLOT)
 146                     == SMRAM_GPA, "could not allocate guest physical addresses?");
 147
 148         memset(addr_gpa2hva(vm, SMRAM_GPA), 0x0, SMRAM_SIZE);
 149         memcpy(addr_gpa2hva(vm, SMRAM_GPA) + 0x8000, smi_handler,
 150                sizeof(smi_handler));
 151
 152         vcpu_set_msr(vcpu, MSR_IA32_SMBASE, SMRAM_GPA);
 153
 154         if (kvm_has_cap(KVM_CAP_NESTED_STATE)) {
 155                 if (kvm_cpu_has(X86_FEATURE_SVM))
 156                         vcpu_alloc_svm(vm, &nested_gva);
 157                 else if (kvm_cpu_has(X86_FEATURE_VMX))
 158                         vcpu_alloc_vmx(vm, &nested_gva);
 159         }
 160
 161         if (!nested_gva)
 162                 pr_info("will skip SMM test with VMX enabled\n");
 163
 164         vcpu_args_set(vcpu, 1, nested_gva);
 165
 166         for (stage = 1;; stage++) {
 167                 vcpu_run(vcpu);
 168                 TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
 169
 170                 memset(&regs, 0, sizeof(regs));
 171                 vcpu_regs_get(vcpu, &regs);
 172
 173                 stage_reported = regs.rax & 0xff;
 174
 175                 if (stage_reported == DONE)
 176                         goto done;
 177
 178                 TEST_ASSERT(stage_reported == stage ||
 179                             stage_reported == SMRAM_STAGE,
 180                             "Unexpected stage: #%x, got %x",
 181                             stage, stage_reported);
 182
 183                 /*
 184                  * Enter SMM during L2 execution and check that we correctly
 185                  * return from it. Do not perform save/restore while in SMM yet.
 186                  */
 187                 if (stage == 8) {
 188                         inject_smi(vcpu);
 189                         continue;
 190                 }
 191
 192                 /*
 193                  * Perform save/restore while the guest is in SMM triggered
 194                  * during L2 execution.
 195                  */
 196                 if (stage == 10)
 197                         inject_smi(vcpu);
 198
 199                 state = vcpu_save_state(vcpu);
 200                 kvm_vm_release(vm);
 201
 202                 vcpu = vm_recreate_with_one_vcpu(vm);
 203                 vcpu_load_state(vcpu, state);
 204                 kvm_x86_state_cleanup(state);
 205         }
 206
 207 done:
 208         kvm_vm_free(vm);
 209 }