target/arm/kvm.c

   1 /*
   2  * ARM implementation of KVM hooks
   3  *
   4  * Copyright Christoffer Dall 2009-2010
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7  * See the COPYING file in the top-level directory.
   8  *
   9  */
  10
  11 #include "qemu/osdep.h"
  12 #include <sys/ioctl.h>
  13
  14 #include <linux/kvm.h>
  15
  16 #include "qemu-common.h"
  17 #include "qemu/timer.h"
  18 #include "qemu/error-report.h"
  19 #include "sysemu/sysemu.h"
  20 #include "sysemu/kvm.h"
  21 #include "kvm_arm.h"
  22 #include "cpu.h"
  23 #include "internals.h"
  24 #include "hw/arm/arm.h"
  25 #include "exec/memattrs.h"
  26 #include "exec/address-spaces.h"
  27 #include "hw/boards.h"
  28 #include "qemu/log.h"
  29
  30 const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
  31     KVM_CAP_LAST_INFO
  32 };
  33
  34 static bool cap_has_mp_state;
  35
  36 static ARMHostCPUFeatures arm_host_cpu_features;
  37
  38 int kvm_arm_vcpu_init(CPUState *cs)
  39 {
  40     ARMCPU *cpu = ARM_CPU(cs);
  41     struct kvm_vcpu_init init;
  42
  43     init.target = cpu->kvm_target;
  44     memcpy(init.features, cpu->kvm_init_features, sizeof(init.features));
  45
  46     return kvm_vcpu_ioctl(cs, KVM_ARM_VCPU_INIT, &init);
  47 }
  48
  49 bool kvm_arm_create_scratch_host_vcpu(const uint32_t *cpus_to_try,
  50                                       int *fdarray,
  51                                       struct kvm_vcpu_init *init)
  52 {
  53     int ret, kvmfd = -1, vmfd = -1, cpufd = -1;
  54
  55     kvmfd = qemu_open("/dev/kvm", O_RDWR);
  56     if (kvmfd < 0) {
  57         goto err;
  58     }
  59     vmfd = ioctl(kvmfd, KVM_CREATE_VM, 0);
  60     if (vmfd < 0) {
  61         goto err;
  62     }
  63     cpufd = ioctl(vmfd, KVM_CREATE_VCPU, 0);
  64     if (cpufd < 0) {
  65         goto err;
  66     }
  67
  68     if (!init) {
  69         /* Caller doesn't want the VCPU to be initialized, so skip it */
  70         goto finish;
  71     }
  72
  73     ret = ioctl(vmfd, KVM_ARM_PREFERRED_TARGET, init);
  74     if (ret >= 0) {
  75         ret = ioctl(cpufd, KVM_ARM_VCPU_INIT, init);
  76         if (ret < 0) {
  77             goto err;
  78         }
  79     } else if (cpus_to_try) {
  80         /* Old kernel which doesn't know about the
  81          * PREFERRED_TARGET ioctl: we know it will only support
  82          * creating one kind of guest CPU which is its preferred
  83          * CPU type.
  84          */
  85         while (*cpus_to_try != QEMU_KVM_ARM_TARGET_NONE) {
  86             init->target = *cpus_to_try++;
  87             memset(init->features, 0, sizeof(init->features));
  88             ret = ioctl(cpufd, KVM_ARM_VCPU_INIT, init);
  89             if (ret >= 0) {
  90                 break;
  91             }
  92         }
  93         if (ret < 0) {
  94             goto err;
  95         }
  96     } else {
  97         /* Treat a NULL cpus_to_try argument the same as an empty
  98          * list, which means we will fail the call since this must
  99          * be an old kernel which doesn't support PREFERRED_TARGET.
 100          */
 101         goto err;
 102     }
 103
 104 finish:
 105     fdarray[0] = kvmfd;
 106     fdarray[1] = vmfd;
 107     fdarray[2] = cpufd;
 108
 109     return true;
 110
 111 err:
 112     if (cpufd >= 0) {
 113         close(cpufd);
 114     }
 115     if (vmfd >= 0) {
 116         close(vmfd);
 117     }
 118     if (kvmfd >= 0) {
 119         close(kvmfd);
 120     }
 121
 122     return false;
 123 }
 124
 125 void kvm_arm_destroy_scratch_host_vcpu(int *fdarray)
 126 {
 127     int i;
 128
 129     for (i = 2; i >= 0; i--) {
 130         close(fdarray[i]);
 131     }
 132 }
 133
 134 void kvm_arm_set_cpu_features_from_host(ARMCPU *cpu)
 135 {
 136     CPUARMState *env = &cpu->env;
 137
 138     if (!arm_host_cpu_features.dtb_compatible) {
 139         if (!kvm_enabled() ||
 140             !kvm_arm_get_host_cpu_features(&arm_host_cpu_features)) {
 141             /* We can't report this error yet, so flag that we need to
 142              * in arm_cpu_realizefn().
 143              */
 144             cpu->kvm_target = QEMU_KVM_ARM_TARGET_NONE;
 145             cpu->host_cpu_probe_failed = true;
 146             return;
 147         }
 148     }
 149
 150     cpu->kvm_target = arm_host_cpu_features.target;
 151     cpu->dtb_compatible = arm_host_cpu_features.dtb_compatible;
 152     env->features = arm_host_cpu_features.features;
 153 }
 154
 155 static void kvm_arm_host_cpu_initfn(Object *obj)
 156 {
 157     ARMCPU *cpu = ARM_CPU(obj);
 158
 159     kvm_arm_set_cpu_features_from_host(cpu);
 160 }
 161
 162 static const TypeInfo host_arm_cpu_type_info = {
 163     .name = TYPE_ARM_HOST_CPU,
 164 #ifdef TARGET_AARCH64
 165     .parent = TYPE_AARCH64_CPU,
 166 #else
 167     .parent = TYPE_ARM_CPU,
 168 #endif
 169     .instance_init = kvm_arm_host_cpu_initfn,
 170 };
 171
 172 int kvm_arch_init(MachineState *ms, KVMState *s)
 173 {
 174     /* For ARM interrupt delivery is always asynchronous,
 175      * whether we are using an in-kernel VGIC or not.
 176      */
 177     kvm_async_interrupts_allowed = true;
 178
 179     /*
 180      * PSCI wakes up secondary cores, so we always need to
 181      * have vCPUs waiting in kernel space
 182      */
 183     kvm_halt_in_kernel_allowed = true;
 184
 185     cap_has_mp_state = kvm_check_extension(s, KVM_CAP_MP_STATE);
 186
 187     type_register_static(&host_arm_cpu_type_info);
 188
 189     return 0;
 190 }
 191
 192 unsigned long kvm_arch_vcpu_id(CPUState *cpu)
 193 {
 194     return cpu->cpu_index;
 195 }
 196
 197 /* We track all the KVM devices which need their memory addresses
 198  * passing to the kernel in a list of these structures.
 199  * When board init is complete we run through the list and
 200  * tell the kernel the base addresses of the memory regions.
 201  * We use a MemoryListener to track mapping and unmapping of
 202  * the regions during board creation, so the board models don't
 203  * need to do anything special for the KVM case.
 204  */
 205 typedef struct KVMDevice {
 206     struct kvm_arm_device_addr kda;
 207     struct kvm_device_attr kdattr;
 208     MemoryRegion *mr;
 209     QSLIST_ENTRY(KVMDevice) entries;
 210     int dev_fd;
 211 } KVMDevice;
 212
 213 static QSLIST_HEAD(kvm_devices_head, KVMDevice) kvm_devices_head;
 214
 215 static void kvm_arm_devlistener_add(MemoryListener *listener,
 216                                     MemoryRegionSection *section)
 217 {
 218     KVMDevice *kd;
 219
 220     QSLIST_FOREACH(kd, &kvm_devices_head, entries) {
 221         if (section->mr == kd->mr) {
 222             kd->kda.addr = section->offset_within_address_space;
 223         }
 224     }
 225 }
 226
 227 static void kvm_arm_devlistener_del(MemoryListener *listener,
 228                                     MemoryRegionSection *section)
 229 {
 230     KVMDevice *kd;
 231
 232     QSLIST_FOREACH(kd, &kvm_devices_head, entries) {
 233         if (section->mr == kd->mr) {
 234             kd->kda.addr = -1;
 235         }
 236     }
 237 }
 238
 239 static MemoryListener devlistener = {
 240     .region_add = kvm_arm_devlistener_add,
 241     .region_del = kvm_arm_devlistener_del,
 242 };
 243
 244 static void kvm_arm_set_device_addr(KVMDevice *kd)
 245 {
 246     struct kvm_device_attr *attr = &kd->kdattr;
 247     int ret;
 248
 249     /* If the device control API is available and we have a device fd on the
 250      * KVMDevice struct, let's use the newer API
 251      */
 252     if (kd->dev_fd >= 0) {
 253         uint64_t addr = kd->kda.addr;
 254         attr->addr = (uintptr_t)&addr;
 255         ret = kvm_device_ioctl(kd->dev_fd, KVM_SET_DEVICE_ATTR, attr);
 256     } else {
 257         ret = kvm_vm_ioctl(kvm_state, KVM_ARM_SET_DEVICE_ADDR, &kd->kda);
 258     }
 259
 260     if (ret < 0) {
 261         fprintf(stderr, "Failed to set device address: %s\n",
 262                 strerror(-ret));
 263         abort();
 264     }
 265 }
 266
 267 static void kvm_arm_machine_init_done(Notifier *notifier, void *data)
 268 {
 269     KVMDevice *kd, *tkd;
 270
 271     QSLIST_FOREACH_SAFE(kd, &kvm_devices_head, entries, tkd) {
 272         if (kd->kda.addr != -1) {
 273             kvm_arm_set_device_addr(kd);
 274         }
 275         memory_region_unref(kd->mr);
 276         g_free(kd);
 277     }
 278     memory_listener_unregister(&devlistener);
 279 }
 280
 281 static Notifier notify = {
 282     .notify = kvm_arm_machine_init_done,
 283 };
 284
 285 void kvm_arm_register_device(MemoryRegion *mr, uint64_t devid, uint64_t group,
 286                              uint64_t attr, int dev_fd)
 287 {
 288     KVMDevice *kd;
 289
 290     if (!kvm_irqchip_in_kernel()) {
 291         return;
 292     }
 293
 294     if (QSLIST_EMPTY(&kvm_devices_head)) {
 295         memory_listener_register(&devlistener, &address_space_memory);
 296         qemu_add_machine_init_done_notifier(&notify);
 297     }
 298     kd = g_new0(KVMDevice, 1);
 299     kd->mr = mr;
 300     kd->kda.id = devid;
 301     kd->kda.addr = -1;
 302     kd->kdattr.flags = 0;
 303     kd->kdattr.group = group;
 304     kd->kdattr.attr = attr;
 305     kd->dev_fd = dev_fd;
 306     QSLIST_INSERT_HEAD(&kvm_devices_head, kd, entries);
 307     memory_region_ref(kd->mr);
 308 }
 309
 310 static int compare_u64(const void *a, const void *b)
 311 {
 312     if (*(uint64_t *)a > *(uint64_t *)b) {
 313         return 1;
 314     }
 315     if (*(uint64_t *)a < *(uint64_t *)b) {
 316         return -1;
 317     }
 318     return 0;
 319 }
 320
 321 /* Initialize the CPUState's cpreg list according to the kernel's
 322  * definition of what CPU registers it knows about (and throw away
 323  * the previous TCG-created cpreg list).
 324  */
 325 int kvm_arm_init_cpreg_list(ARMCPU *cpu)
 326 {
 327     struct kvm_reg_list rl;
 328     struct kvm_reg_list *rlp;
 329     int i, ret, arraylen;
 330     CPUState *cs = CPU(cpu);
 331
 332     rl.n = 0;
 333     ret = kvm_vcpu_ioctl(cs, KVM_GET_REG_LIST, &rl);
 334     if (ret != -E2BIG) {
 335         return ret;
 336     }
 337     rlp = g_malloc(sizeof(struct kvm_reg_list) + rl.n * sizeof(uint64_t));
 338     rlp->n = rl.n;
 339     ret = kvm_vcpu_ioctl(cs, KVM_GET_REG_LIST, rlp);
 340     if (ret) {
 341         goto out;
 342     }
 343     /* Sort the list we get back from the kernel, since cpreg_tuples
 344      * must be in strictly ascending order.
 345      */
 346     qsort(&rlp->reg, rlp->n, sizeof(rlp->reg[0]), compare_u64);
 347
 348     for (i = 0, arraylen = 0; i < rlp->n; i++) {
 349         if (!kvm_arm_reg_syncs_via_cpreg_list(rlp->reg[i])) {
 350             continue;
 351         }
 352         switch (rlp->reg[i] & KVM_REG_SIZE_MASK) {
 353         case KVM_REG_SIZE_U32:
 354         case KVM_REG_SIZE_U64:
 355             break;
 356         default:
 357             fprintf(stderr, "Can't handle size of register in kernel list\n");
 358             ret = -EINVAL;
 359             goto out;
 360         }
 361
 362         arraylen++;
 363     }
 364
 365     cpu->cpreg_indexes = g_renew(uint64_t, cpu->cpreg_indexes, arraylen);
 366     cpu->cpreg_values = g_renew(uint64_t, cpu->cpreg_values, arraylen);
 367     cpu->cpreg_vmstate_indexes = g_renew(uint64_t, cpu->cpreg_vmstate_indexes,
 368                                          arraylen);
 369     cpu->cpreg_vmstate_values = g_renew(uint64_t, cpu->cpreg_vmstate_values,
 370                                         arraylen);
 371     cpu->cpreg_array_len = arraylen;
 372     cpu->cpreg_vmstate_array_len = arraylen;
 373
 374     for (i = 0, arraylen = 0; i < rlp->n; i++) {
 375         uint64_t regidx = rlp->reg[i];
 376         if (!kvm_arm_reg_syncs_via_cpreg_list(regidx)) {
 377             continue;
 378         }
 379         cpu->cpreg_indexes[arraylen] = regidx;
 380         arraylen++;
 381     }
 382     assert(cpu->cpreg_array_len == arraylen);
 383
 384     if (!write_kvmstate_to_list(cpu)) {
 385         /* Shouldn't happen unless kernel is inconsistent about
 386          * what registers exist.
 387          */
 388         fprintf(stderr, "Initial read of kernel register state failed\n");
 389         ret = -EINVAL;
 390         goto out;
 391     }
 392
 393 out:
 394     g_free(rlp);
 395     return ret;
 396 }
 397
 398 bool write_kvmstate_to_list(ARMCPU *cpu)
 399 {
 400     CPUState *cs = CPU(cpu);
 401     int i;
 402     bool ok = true;
 403
 404     for (i = 0; i < cpu->cpreg_array_len; i++) {
 405         struct kvm_one_reg r;
 406         uint64_t regidx = cpu->cpreg_indexes[i];
 407         uint32_t v32;
 408         int ret;
 409
 410         r.id = regidx;
 411
 412         switch (regidx & KVM_REG_SIZE_MASK) {
 413         case KVM_REG_SIZE_U32:
 414             r.addr = (uintptr_t)&v32;
 415             ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &r);
 416             if (!ret) {
 417                 cpu->cpreg_values[i] = v32;
 418             }
 419             break;
 420         case KVM_REG_SIZE_U64:
 421             r.addr = (uintptr_t)(cpu->cpreg_values + i);
 422             ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &r);
 423             break;
 424         default:
 425             abort();
 426         }
 427         if (ret) {
 428             ok = false;
 429         }
 430     }
 431     return ok;
 432 }
 433
 434 bool write_list_to_kvmstate(ARMCPU *cpu, int level)
 435 {
 436     CPUState *cs = CPU(cpu);
 437     int i;
 438     bool ok = true;
 439
 440     for (i = 0; i < cpu->cpreg_array_len; i++) {
 441         struct kvm_one_reg r;
 442         uint64_t regidx = cpu->cpreg_indexes[i];
 443         uint32_t v32;
 444         int ret;
 445
 446         if (kvm_arm_cpreg_level(regidx) > level) {
 447             continue;
 448         }
 449
 450         r.id = regidx;
 451         switch (regidx & KVM_REG_SIZE_MASK) {
 452         case KVM_REG_SIZE_U32:
 453             v32 = cpu->cpreg_values[i];
 454             r.addr = (uintptr_t)&v32;
 455             break;
 456         case KVM_REG_SIZE_U64:
 457             r.addr = (uintptr_t)(cpu->cpreg_values + i);
 458             break;
 459         default:
 460             abort();
 461         }
 462         ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &r);
 463         if (ret) {
 464             /* We might fail for "unknown register" and also for
 465              * "you tried to set a register which is constant with
 466              * a different value from what it actually contains".
 467              */
 468             ok = false;
 469         }
 470     }
 471     return ok;
 472 }
 473
 474 void kvm_arm_reset_vcpu(ARMCPU *cpu)
 475 {
 476     int ret;
 477
 478     /* Re-init VCPU so that all registers are set to
 479      * their respective reset values.
 480      */
 481     ret = kvm_arm_vcpu_init(CPU(cpu));
 482     if (ret < 0) {
 483         fprintf(stderr, "kvm_arm_vcpu_init failed: %s\n", strerror(-ret));
 484         abort();
 485     }
 486     if (!write_kvmstate_to_list(cpu)) {
 487         fprintf(stderr, "write_kvmstate_to_list failed\n");
 488         abort();
 489     }
 490 }
 491
 492 /*
 493  * Update KVM's MP_STATE based on what QEMU thinks it is
 494  */
 495 int kvm_arm_sync_mpstate_to_kvm(ARMCPU *cpu)
 496 {
 497     if (cap_has_mp_state) {
 498         struct kvm_mp_state mp_state = {
 499             .mp_state = (cpu->power_state == PSCI_OFF) ?
 500             KVM_MP_STATE_STOPPED : KVM_MP_STATE_RUNNABLE
 501         };
 502         int ret = kvm_vcpu_ioctl(CPU(cpu), KVM_SET_MP_STATE, &mp_state);
 503         if (ret) {
 504             fprintf(stderr, "%s: failed to set MP_STATE %d/%s\n",
 505                     __func__, ret, strerror(-ret));
 506             return -1;
 507         }
 508     }
 509
 510     return 0;
 511 }
 512
 513 /*
 514  * Sync the KVM MP_STATE into QEMU
 515  */
 516 int kvm_arm_sync_mpstate_to_qemu(ARMCPU *cpu)
 517 {
 518     if (cap_has_mp_state) {
 519         struct kvm_mp_state mp_state;
 520         int ret = kvm_vcpu_ioctl(CPU(cpu), KVM_GET_MP_STATE, &mp_state);
 521         if (ret) {
 522             fprintf(stderr, "%s: failed to get MP_STATE %d/%s\n",
 523                     __func__, ret, strerror(-ret));
 524             abort();
 525         }
 526         cpu->power_state = (mp_state.mp_state == KVM_MP_STATE_STOPPED) ?
 527             PSCI_OFF : PSCI_ON;
 528     }
 529
 530     return 0;
 531 }
 532
 533 void kvm_arch_pre_run(CPUState *cs, struct kvm_run *run)
 534 {
 535 }
 536
 537 MemTxAttrs kvm_arch_post_run(CPUState *cs, struct kvm_run *run)
 538 {
 539     ARMCPU *cpu;
 540     uint32_t switched_level;
 541
 542     if (kvm_irqchip_in_kernel()) {
 543         /*
 544          * We only need to sync timer states with user-space interrupt
 545          * controllers, so return early and save cycles if we don't.
 546          */
 547         return MEMTXATTRS_UNSPECIFIED;
 548     }
 549
 550     cpu = ARM_CPU(cs);
 551
 552     /* Synchronize our shadowed in-kernel device irq lines with the kvm ones */
 553     if (run->s.regs.device_irq_level != cpu->device_irq_level) {
 554         switched_level = cpu->device_irq_level ^ run->s.regs.device_irq_level;
 555
 556         qemu_mutex_lock_iothread();
 557
 558         if (switched_level & KVM_ARM_DEV_EL1_VTIMER) {
 559             qemu_set_irq(cpu->gt_timer_outputs[GTIMER_VIRT],
 560                          !!(run->s.regs.device_irq_level &
 561                             KVM_ARM_DEV_EL1_VTIMER));
 562             switched_level &= ~KVM_ARM_DEV_EL1_VTIMER;
 563         }
 564
 565         if (switched_level & KVM_ARM_DEV_EL1_PTIMER) {
 566             qemu_set_irq(cpu->gt_timer_outputs[GTIMER_PHYS],
 567                          !!(run->s.regs.device_irq_level &
 568                             KVM_ARM_DEV_EL1_PTIMER));
 569             switched_level &= ~KVM_ARM_DEV_EL1_PTIMER;
 570         }
 571
 572         if (switched_level & KVM_ARM_DEV_PMU) {
 573             qemu_set_irq(cpu->pmu_interrupt,
 574                          !!(run->s.regs.device_irq_level & KVM_ARM_DEV_PMU));
 575             switched_level &= ~KVM_ARM_DEV_PMU;
 576         }
 577
 578         if (switched_level) {
 579             qemu_log_mask(LOG_UNIMP, "%s: unhandled in-kernel device IRQ %x\n",
 580                           __func__, switched_level);
 581         }
 582
 583         /* We also mark unknown levels as processed to not waste cycles */
 584         cpu->device_irq_level = run->s.regs.device_irq_level;
 585         qemu_mutex_unlock_iothread();
 586     }
 587
 588     return MEMTXATTRS_UNSPECIFIED;
 589 }
 590
 591
 592 int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
 593 {
 594     int ret = 0;
 595
 596     switch (run->exit_reason) {
 597     case KVM_EXIT_DEBUG:
 598         if (kvm_arm_handle_debug(cs, &run->debug.arch)) {
 599             ret = EXCP_DEBUG;
 600         } /* otherwise return to guest */
 601         break;
 602     default:
 603         qemu_log_mask(LOG_UNIMP, "%s: un-handled exit reason %d\n",
 604                       __func__, run->exit_reason);
 605         break;
 606     }
 607     return ret;
 608 }
 609
 610 bool kvm_arch_stop_on_emulation_error(CPUState *cs)
 611 {
 612     return true;
 613 }
 614
 615 int kvm_arch_process_async_events(CPUState *cs)
 616 {
 617     return 0;
 618 }
 619
 620 /* The #ifdef protections are until 32bit headers are imported and can
 621  * be removed once both 32 and 64 bit reach feature parity.
 622  */
 623 void kvm_arch_update_guest_debug(CPUState *cs, struct kvm_guest_debug *dbg)
 624 {
 625 #ifdef KVM_GUESTDBG_USE_SW_BP
 626     if (kvm_sw_breakpoints_active(cs)) {
 627         dbg->control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP;
 628     }
 629 #endif
 630 #ifdef KVM_GUESTDBG_USE_HW
 631     if (kvm_arm_hw_debug_active(cs)) {
 632         dbg->control |= KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_HW;
 633         kvm_arm_copy_hw_debug_data(&dbg->arch);
 634     }
 635 #endif
 636 }
 637
 638 void kvm_arch_init_irq_routing(KVMState *s)
 639 {
 640 }
 641
 642 int kvm_arch_irqchip_create(MachineState *ms, KVMState *s)
 643 {
 644      if (machine_kernel_irqchip_split(ms)) {
 645          perror("-machine kernel_irqchip=split is not supported on ARM.");
 646          exit(1);
 647     }
 648
 649     /* If we can create the VGIC using the newer device control API, we
 650      * let the device do this when it initializes itself, otherwise we
 651      * fall back to the old API */
 652     return kvm_check_extension(s, KVM_CAP_DEVICE_CTRL);
 653 }
 654
 655 int kvm_arm_vgic_probe(void)
 656 {
 657     if (kvm_create_device(kvm_state,
 658                           KVM_DEV_TYPE_ARM_VGIC_V3, true) == 0) {
 659         return 3;
 660     } else if (kvm_create_device(kvm_state,
 661                                  KVM_DEV_TYPE_ARM_VGIC_V2, true) == 0) {
 662         return 2;
 663     } else {
 664         return 0;
 665     }
 666 }
 667
 668 int kvm_arch_fixup_msi_route(struct kvm_irq_routing_entry *route,
 669                              uint64_t address, uint32_t data, PCIDevice *dev)
 670 {
 671     return 0;
 672 }
 673
 674 int kvm_arch_add_msi_route_post(struct kvm_irq_routing_entry *route,
 675                                 int vector, PCIDevice *dev)
 676 {
 677     return 0;
 678 }
 679
 680 int kvm_arch_release_virq_post(int virq)
 681 {
 682     return 0;
 683 }
 684
 685 int kvm_arch_msi_data_to_gsi(uint32_t data)
 686 {
 687     return (data - 32) & 0xffff;
 688 }