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

   1 /*
   2  * vmx_set_nested_state_test
   3  *
   4  * Copyright (C) 2019, Google LLC.
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2.
   7  *
   8  * This test verifies the integrity of calling the ioctl KVM_SET_NESTED_STATE.
   9  */
  10
  11 #include "test_util.h"
  12 #include "kvm_util.h"
  13 #include "processor.h"
  14 #include "vmx.h"
  15
  16 #include <errno.h>
  17 #include <linux/kvm.h>
  18 #include <string.h>
  19 #include <sys/ioctl.h>
  20 #include <unistd.h>
  21
  22 /*
  23  * Mirror of VMCS12_REVISION in arch/x86/kvm/vmx/vmcs12.h. If that value
  24  * changes this should be updated.
  25  */
  26 #define VMCS12_REVISION 0x11e57ed0
  27 #define VCPU_ID 5
  28
  29 void test_nested_state(struct kvm_vm *vm, struct kvm_nested_state *state)
  30 {
  31         volatile struct kvm_run *run;
  32
  33         vcpu_nested_state_set(vm, VCPU_ID, state, false);
  34         run = vcpu_state(vm, VCPU_ID);
  35         vcpu_run(vm, VCPU_ID);
  36         TEST_ASSERT(run->exit_reason == KVM_EXIT_SHUTDOWN,
  37                 "Got exit_reason other than KVM_EXIT_SHUTDOWN: %u (%s),\n",
  38                 run->exit_reason,
  39                 exit_reason_str(run->exit_reason));
  40 }
  41
  42 void test_nested_state_expect_errno(struct kvm_vm *vm,
  43                                     struct kvm_nested_state *state,
  44                                     int expected_errno)
  45 {
  46         volatile struct kvm_run *run;
  47         int rv;
  48
  49         rv = vcpu_nested_state_set(vm, VCPU_ID, state, true);
  50         TEST_ASSERT(rv == -1 && errno == expected_errno,
  51                 "Expected %s (%d) from vcpu_nested_state_set but got rv: %i errno: %s (%d)",
  52                 strerror(expected_errno), expected_errno, rv, strerror(errno),
  53                 errno);
  54         run = vcpu_state(vm, VCPU_ID);
  55         vcpu_run(vm, VCPU_ID);
  56         TEST_ASSERT(run->exit_reason == KVM_EXIT_SHUTDOWN,
  57                 "Got exit_reason other than KVM_EXIT_SHUTDOWN: %u (%s),\n",
  58                 run->exit_reason,
  59                 exit_reason_str(run->exit_reason));
  60 }
  61
  62 void test_nested_state_expect_einval(struct kvm_vm *vm,
  63                                      struct kvm_nested_state *state)
  64 {
  65         test_nested_state_expect_errno(vm, state, EINVAL);
  66 }
  67
  68 void test_nested_state_expect_efault(struct kvm_vm *vm,
  69                                      struct kvm_nested_state *state)
  70 {
  71         test_nested_state_expect_errno(vm, state, EFAULT);
  72 }
  73
  74 void set_revision_id_for_vmcs12(struct kvm_nested_state *state,
  75                                 u32 vmcs12_revision)
  76 {
  77         /* Set revision_id in vmcs12 to vmcs12_revision. */
  78         memcpy(&state->data, &vmcs12_revision, sizeof(u32));
  79 }
  80
  81 void set_default_state(struct kvm_nested_state *state)
  82 {
  83         memset(state, 0, sizeof(*state));
  84         state->flags = KVM_STATE_NESTED_RUN_PENDING |
  85                        KVM_STATE_NESTED_GUEST_MODE;
  86         state->format = 0;
  87         state->size = sizeof(*state);
  88 }
  89
  90 void set_default_vmx_state(struct kvm_nested_state *state, int size)
  91 {
  92         memset(state, 0, size);
  93         state->flags = KVM_STATE_NESTED_GUEST_MODE  |
  94                         KVM_STATE_NESTED_RUN_PENDING |
  95                         KVM_STATE_NESTED_EVMCS;
  96         state->format = 0;
  97         state->size = size;
  98         state->hdr.vmx.vmxon_pa = 0x1000;
  99         state->hdr.vmx.vmcs12_pa = 0x2000;
 100         state->hdr.vmx.smm.flags = 0;
 101         set_revision_id_for_vmcs12(state, VMCS12_REVISION);
 102 }
 103
 104 void test_vmx_nested_state(struct kvm_vm *vm)
 105 {
 106         /* Add a page for VMCS12. */
 107         const int state_sz = sizeof(struct kvm_nested_state) + getpagesize();
 108         struct kvm_nested_state *state =
 109                 (struct kvm_nested_state *)malloc(state_sz);
 110
 111         /* The format must be set to 0. 0 for VMX, 1 for SVM. */
 112         set_default_vmx_state(state, state_sz);
 113         state->format = 1;
 114         test_nested_state_expect_einval(vm, state);
 115
 116         /*
 117          * We cannot virtualize anything if the guest does not have VMX
 118          * enabled.
 119          */
 120         set_default_vmx_state(state, state_sz);
 121         test_nested_state_expect_einval(vm, state);
 122
 123         /*
 124          * We cannot virtualize anything if the guest does not have VMX
 125          * enabled.  We expect KVM_SET_NESTED_STATE to return 0 if vmxon_pa
 126          * is set to -1ull.
 127          */
 128         set_default_vmx_state(state, state_sz);
 129         state->hdr.vmx.vmxon_pa = -1ull;
 130         test_nested_state(vm, state);
 131
 132         /* Enable VMX in the guest CPUID. */
 133         vcpu_set_cpuid(vm, VCPU_ID, kvm_get_supported_cpuid());
 134
 135         /* It is invalid to have vmxon_pa == -1ull and SMM flags non-zero. */
 136         set_default_vmx_state(state, state_sz);
 137         state->hdr.vmx.vmxon_pa = -1ull;
 138         state->hdr.vmx.smm.flags = 1;
 139         test_nested_state_expect_einval(vm, state);
 140
 141         /* It is invalid to have vmxon_pa == -1ull and vmcs_pa != -1ull. */
 142         set_default_vmx_state(state, state_sz);
 143         state->hdr.vmx.vmxon_pa = -1ull;
 144         state->hdr.vmx.vmcs12_pa = 0;
 145         test_nested_state_expect_einval(vm, state);
 146
 147         /*
 148          * Setting vmxon_pa == -1ull and vmcs_pa == -1ull exits early without
 149          * setting the nested state.
 150          */
 151         set_default_vmx_state(state, state_sz);
 152         state->hdr.vmx.vmxon_pa = -1ull;
 153         state->hdr.vmx.vmcs12_pa = -1ull;
 154         test_nested_state(vm, state);
 155
 156         /* It is invalid to have vmxon_pa set to a non-page aligned address. */
 157         set_default_vmx_state(state, state_sz);
 158         state->hdr.vmx.vmxon_pa = 1;
 159         test_nested_state_expect_einval(vm, state);
 160
 161         /*
 162          * It is invalid to have KVM_STATE_NESTED_SMM_GUEST_MODE and
 163          * KVM_STATE_NESTED_GUEST_MODE set together.
 164          */
 165         set_default_vmx_state(state, state_sz);
 166         state->flags = KVM_STATE_NESTED_GUEST_MODE  |
 167                       KVM_STATE_NESTED_RUN_PENDING;
 168         state->hdr.vmx.smm.flags = KVM_STATE_NESTED_SMM_GUEST_MODE;
 169         test_nested_state_expect_einval(vm, state);
 170
 171         /*
 172          * It is invalid to have any of the SMM flags set besides:
 173          *      KVM_STATE_NESTED_SMM_GUEST_MODE
 174          *      KVM_STATE_NESTED_SMM_VMXON
 175          */
 176         set_default_vmx_state(state, state_sz);
 177         state->hdr.vmx.smm.flags = ~(KVM_STATE_NESTED_SMM_GUEST_MODE |
 178                                 KVM_STATE_NESTED_SMM_VMXON);
 179         test_nested_state_expect_einval(vm, state);
 180
 181         /* Outside SMM, SMM flags must be zero. */
 182         set_default_vmx_state(state, state_sz);
 183         state->flags = 0;
 184         state->hdr.vmx.smm.flags = KVM_STATE_NESTED_SMM_GUEST_MODE;
 185         test_nested_state_expect_einval(vm, state);
 186
 187         /* Size must be large enough to fit kvm_nested_state and vmcs12. */
 188         set_default_vmx_state(state, state_sz);
 189         state->size = sizeof(*state);
 190         test_nested_state(vm, state);
 191
 192         /* vmxon_pa cannot be the same address as vmcs_pa. */
 193         set_default_vmx_state(state, state_sz);
 194         state->hdr.vmx.vmxon_pa = 0;
 195         state->hdr.vmx.vmcs12_pa = 0;
 196         test_nested_state_expect_einval(vm, state);
 197
 198         /* The revision id for vmcs12 must be VMCS12_REVISION. */
 199         set_default_vmx_state(state, state_sz);
 200         set_revision_id_for_vmcs12(state, 0);
 201         test_nested_state_expect_einval(vm, state);
 202
 203         /*
 204          * Test that if we leave nesting the state reflects that when we get
 205          * it again.
 206          */
 207         set_default_vmx_state(state, state_sz);
 208         state->hdr.vmx.vmxon_pa = -1ull;
 209         state->hdr.vmx.vmcs12_pa = -1ull;
 210         state->flags = 0;
 211         test_nested_state(vm, state);
 212         vcpu_nested_state_get(vm, VCPU_ID, state);
 213         TEST_ASSERT(state->size >= sizeof(*state) && state->size <= state_sz,
 214                     "Size must be between %d and %d.  The size returned was %d.",
 215                     sizeof(*state), state_sz, state->size);
 216         TEST_ASSERT(state->hdr.vmx.vmxon_pa == -1ull, "vmxon_pa must be -1ull.");
 217         TEST_ASSERT(state->hdr.vmx.vmcs12_pa == -1ull, "vmcs_pa must be -1ull.");
 218
 219         free(state);
 220 }
 221
 222 int main(int argc, char *argv[])
 223 {
 224         struct kvm_vm *vm;
 225         struct kvm_nested_state state;
 226         struct kvm_cpuid_entry2 *entry = kvm_get_supported_cpuid_entry(1);
 227
 228         if (!kvm_check_cap(KVM_CAP_NESTED_STATE)) {
 229                 printf("KVM_CAP_NESTED_STATE not available, skipping test\n");
 230                 exit(KSFT_SKIP);
 231         }
 232
 233         /*
 234          * AMD currently does not implement set_nested_state, so for now we
 235          * just early out.
 236          */
 237         if (!(entry->ecx & CPUID_VMX)) {
 238                 fprintf(stderr, "nested VMX not enabled, skipping test\n");
 239                 exit(KSFT_SKIP);
 240         }
 241
 242         vm = vm_create_default(VCPU_ID, 0, 0);
 243
 244         /* Passing a NULL kvm_nested_state causes a EFAULT. */
 245         test_nested_state_expect_efault(vm, NULL);
 246
 247         /* 'size' cannot be smaller than sizeof(kvm_nested_state). */
 248         set_default_state(&state);
 249         state.size = 0;
 250         test_nested_state_expect_einval(vm, &state);
 251
 252         /*
 253          * Setting the flags 0xf fails the flags check.  The only flags that
 254          * can be used are:
 255          *     KVM_STATE_NESTED_GUEST_MODE
 256          *     KVM_STATE_NESTED_RUN_PENDING
 257          *     KVM_STATE_NESTED_EVMCS
 258          */
 259         set_default_state(&state);
 260         state.flags = 0xf;
 261         test_nested_state_expect_einval(vm, &state);
 262
 263         /*
 264          * If KVM_STATE_NESTED_RUN_PENDING is set then
 265          * KVM_STATE_NESTED_GUEST_MODE has to be set as well.
 266          */
 267         set_default_state(&state);
 268         state.flags = KVM_STATE_NESTED_RUN_PENDING;
 269         test_nested_state_expect_einval(vm, &state);
 270
 271         /*
 272          * TODO: When SVM support is added for KVM_SET_NESTED_STATE
 273          *       add tests here to support it like VMX.
 274          */
 275         if (entry->ecx & CPUID_VMX)
 276                 test_vmx_nested_state(vm);
 277
 278         kvm_vm_free(vm);
 279         return 0;
 280 }