qemu/hw/acpi/cpu.c
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   1#include "qemu/osdep.h"
   2#include "migration/vmstate.h"
   3#include "hw/acpi/cpu.h"
   4#include "qapi/error.h"
   5#include "qapi/qapi-events-acpi.h"
   6#include "trace.h"
   7#include "sysemu/numa.h"
   8
   9#define ACPI_CPU_HOTPLUG_REG_LEN 12
  10#define ACPI_CPU_SELECTOR_OFFSET_WR 0
  11#define ACPI_CPU_FLAGS_OFFSET_RW 4
  12#define ACPI_CPU_CMD_OFFSET_WR 5
  13#define ACPI_CPU_CMD_DATA_OFFSET_RW 8
  14#define ACPI_CPU_CMD_DATA2_OFFSET_R 0
  15
  16#define OVMF_CPUHP_SMI_CMD 4
  17
  18enum {
  19    CPHP_GET_NEXT_CPU_WITH_EVENT_CMD = 0,
  20    CPHP_OST_EVENT_CMD = 1,
  21    CPHP_OST_STATUS_CMD = 2,
  22    CPHP_GET_CPU_ID_CMD = 3,
  23    CPHP_CMD_MAX
  24};
  25
  26static ACPIOSTInfo *acpi_cpu_device_status(int idx, AcpiCpuStatus *cdev)
  27{
  28    ACPIOSTInfo *info = g_new0(ACPIOSTInfo, 1);
  29
  30    info->slot_type = ACPI_SLOT_TYPE_CPU;
  31    info->slot = g_strdup_printf("%d", idx);
  32    info->source = cdev->ost_event;
  33    info->status = cdev->ost_status;
  34    if (cdev->cpu) {
  35        DeviceState *dev = DEVICE(cdev->cpu);
  36        if (dev->id) {
  37            info->device = g_strdup(dev->id);
  38            info->has_device = true;
  39        }
  40    }
  41    return info;
  42}
  43
  44void acpi_cpu_ospm_status(CPUHotplugState *cpu_st, ACPIOSTInfoList ***list)
  45{
  46    ACPIOSTInfoList ***tail = list;
  47    int i;
  48
  49    for (i = 0; i < cpu_st->dev_count; i++) {
  50        QAPI_LIST_APPEND(*tail, acpi_cpu_device_status(i, &cpu_st->devs[i]));
  51    }
  52}
  53
  54static uint64_t cpu_hotplug_rd(void *opaque, hwaddr addr, unsigned size)
  55{
  56    uint64_t val = 0;
  57    CPUHotplugState *cpu_st = opaque;
  58    AcpiCpuStatus *cdev;
  59
  60    if (cpu_st->selector >= cpu_st->dev_count) {
  61        return val;
  62    }
  63
  64    cdev = &cpu_st->devs[cpu_st->selector];
  65    switch (addr) {
  66    case ACPI_CPU_FLAGS_OFFSET_RW: /* pack and return is_* fields */
  67        val |= cdev->cpu ? 1 : 0;
  68        val |= cdev->is_inserting ? 2 : 0;
  69        val |= cdev->is_removing  ? 4 : 0;
  70        val |= cdev->fw_remove  ? 16 : 0;
  71        trace_cpuhp_acpi_read_flags(cpu_st->selector, val);
  72        break;
  73    case ACPI_CPU_CMD_DATA_OFFSET_RW:
  74        switch (cpu_st->command) {
  75        case CPHP_GET_NEXT_CPU_WITH_EVENT_CMD:
  76           val = cpu_st->selector;
  77           break;
  78        case CPHP_GET_CPU_ID_CMD:
  79           val = cdev->arch_id & 0xFFFFFFFF;
  80           break;
  81        default:
  82           break;
  83        }
  84        trace_cpuhp_acpi_read_cmd_data(cpu_st->selector, val);
  85        break;
  86    case ACPI_CPU_CMD_DATA2_OFFSET_R:
  87        switch (cpu_st->command) {
  88        case CPHP_GET_NEXT_CPU_WITH_EVENT_CMD:
  89           val = 0;
  90           break;
  91        case CPHP_GET_CPU_ID_CMD:
  92           val = cdev->arch_id >> 32;
  93           break;
  94        default:
  95           break;
  96        }
  97        trace_cpuhp_acpi_read_cmd_data2(cpu_st->selector, val);
  98        break;
  99    default:
 100        break;
 101    }
 102    return val;
 103}
 104
 105static void cpu_hotplug_wr(void *opaque, hwaddr addr, uint64_t data,
 106                           unsigned int size)
 107{
 108    CPUHotplugState *cpu_st = opaque;
 109    AcpiCpuStatus *cdev;
 110    ACPIOSTInfo *info;
 111
 112    assert(cpu_st->dev_count);
 113
 114    if (addr) {
 115        if (cpu_st->selector >= cpu_st->dev_count) {
 116            trace_cpuhp_acpi_invalid_idx_selected(cpu_st->selector);
 117            return;
 118        }
 119    }
 120
 121    switch (addr) {
 122    case ACPI_CPU_SELECTOR_OFFSET_WR: /* current CPU selector */
 123        cpu_st->selector = data;
 124        trace_cpuhp_acpi_write_idx(cpu_st->selector);
 125        break;
 126    case ACPI_CPU_FLAGS_OFFSET_RW: /* set is_* fields  */
 127        cdev = &cpu_st->devs[cpu_st->selector];
 128        if (data & 2) { /* clear insert event */
 129            cdev->is_inserting = false;
 130            trace_cpuhp_acpi_clear_inserting_evt(cpu_st->selector);
 131        } else if (data & 4) { /* clear remove event */
 132            cdev->is_removing = false;
 133            trace_cpuhp_acpi_clear_remove_evt(cpu_st->selector);
 134        } else if (data & 8) {
 135            DeviceState *dev = NULL;
 136            HotplugHandler *hotplug_ctrl = NULL;
 137
 138            if (!cdev->cpu || cdev->cpu == first_cpu) {
 139                trace_cpuhp_acpi_ejecting_invalid_cpu(cpu_st->selector);
 140                break;
 141            }
 142
 143            trace_cpuhp_acpi_ejecting_cpu(cpu_st->selector);
 144            dev = DEVICE(cdev->cpu);
 145            hotplug_ctrl = qdev_get_hotplug_handler(dev);
 146            hotplug_handler_unplug(hotplug_ctrl, dev, NULL);
 147            object_unparent(OBJECT(dev));
 148            cdev->fw_remove = false;
 149        } else if (data & 16) {
 150            if (!cdev->cpu || cdev->cpu == first_cpu) {
 151                trace_cpuhp_acpi_fw_remove_invalid_cpu(cpu_st->selector);
 152                break;
 153            }
 154            trace_cpuhp_acpi_fw_remove_cpu(cpu_st->selector);
 155            cdev->fw_remove = true;
 156        }
 157        break;
 158    case ACPI_CPU_CMD_OFFSET_WR:
 159        trace_cpuhp_acpi_write_cmd(cpu_st->selector, data);
 160        if (data < CPHP_CMD_MAX) {
 161            cpu_st->command = data;
 162            if (cpu_st->command == CPHP_GET_NEXT_CPU_WITH_EVENT_CMD) {
 163                uint32_t iter = cpu_st->selector;
 164
 165                do {
 166                    cdev = &cpu_st->devs[iter];
 167                    if (cdev->is_inserting || cdev->is_removing ||
 168                        cdev->fw_remove) {
 169                        cpu_st->selector = iter;
 170                        trace_cpuhp_acpi_cpu_has_events(cpu_st->selector,
 171                            cdev->is_inserting, cdev->is_removing);
 172                        break;
 173                    }
 174                    iter = iter + 1 < cpu_st->dev_count ? iter + 1 : 0;
 175                } while (iter != cpu_st->selector);
 176            }
 177        }
 178        break;
 179    case ACPI_CPU_CMD_DATA_OFFSET_RW:
 180        switch (cpu_st->command) {
 181        case CPHP_OST_EVENT_CMD: {
 182           cdev = &cpu_st->devs[cpu_st->selector];
 183           cdev->ost_event = data;
 184           trace_cpuhp_acpi_write_ost_ev(cpu_st->selector, cdev->ost_event);
 185           break;
 186        }
 187        case CPHP_OST_STATUS_CMD: {
 188           cdev = &cpu_st->devs[cpu_st->selector];
 189           cdev->ost_status = data;
 190           info = acpi_cpu_device_status(cpu_st->selector, cdev);
 191           qapi_event_send_acpi_device_ost(info);
 192           qapi_free_ACPIOSTInfo(info);
 193           trace_cpuhp_acpi_write_ost_status(cpu_st->selector,
 194                                             cdev->ost_status);
 195           break;
 196        }
 197        default:
 198           break;
 199        }
 200        break;
 201    default:
 202        break;
 203    }
 204}
 205
 206static const MemoryRegionOps cpu_hotplug_ops = {
 207    .read = cpu_hotplug_rd,
 208    .write = cpu_hotplug_wr,
 209    .endianness = DEVICE_LITTLE_ENDIAN,
 210    .valid = {
 211        .min_access_size = 1,
 212        .max_access_size = 4,
 213    },
 214};
 215
 216void cpu_hotplug_hw_init(MemoryRegion *as, Object *owner,
 217                         CPUHotplugState *state, hwaddr base_addr)
 218{
 219    MachineState *machine = MACHINE(qdev_get_machine());
 220    MachineClass *mc = MACHINE_GET_CLASS(machine);
 221    const CPUArchIdList *id_list;
 222    int i;
 223
 224    assert(mc->possible_cpu_arch_ids);
 225    id_list = mc->possible_cpu_arch_ids(machine);
 226    state->dev_count = id_list->len;
 227    state->devs = g_new0(typeof(*state->devs), state->dev_count);
 228    for (i = 0; i < id_list->len; i++) {
 229        state->devs[i].cpu =  CPU(id_list->cpus[i].cpu);
 230        state->devs[i].arch_id = id_list->cpus[i].arch_id;
 231    }
 232    memory_region_init_io(&state->ctrl_reg, owner, &cpu_hotplug_ops, state,
 233                          "acpi-cpu-hotplug", ACPI_CPU_HOTPLUG_REG_LEN);
 234    memory_region_add_subregion(as, base_addr, &state->ctrl_reg);
 235}
 236
 237static AcpiCpuStatus *get_cpu_status(CPUHotplugState *cpu_st, DeviceState *dev)
 238{
 239    CPUClass *k = CPU_GET_CLASS(dev);
 240    uint64_t cpu_arch_id = k->get_arch_id(CPU(dev));
 241    int i;
 242
 243    for (i = 0; i < cpu_st->dev_count; i++) {
 244        if (cpu_arch_id == cpu_st->devs[i].arch_id) {
 245            return &cpu_st->devs[i];
 246        }
 247    }
 248    return NULL;
 249}
 250
 251void acpi_cpu_plug_cb(HotplugHandler *hotplug_dev,
 252                      CPUHotplugState *cpu_st, DeviceState *dev, Error **errp)
 253{
 254    AcpiCpuStatus *cdev;
 255
 256    cdev = get_cpu_status(cpu_st, dev);
 257    if (!cdev) {
 258        return;
 259    }
 260
 261    cdev->cpu = CPU(dev);
 262    if (dev->hotplugged) {
 263        cdev->is_inserting = true;
 264        acpi_send_event(DEVICE(hotplug_dev), ACPI_CPU_HOTPLUG_STATUS);
 265    }
 266}
 267
 268void acpi_cpu_unplug_request_cb(HotplugHandler *hotplug_dev,
 269                                CPUHotplugState *cpu_st,
 270                                DeviceState *dev, Error **errp)
 271{
 272    AcpiCpuStatus *cdev;
 273
 274    cdev = get_cpu_status(cpu_st, dev);
 275    if (!cdev) {
 276        return;
 277    }
 278
 279    cdev->is_removing = true;
 280    acpi_send_event(DEVICE(hotplug_dev), ACPI_CPU_HOTPLUG_STATUS);
 281}
 282
 283void acpi_cpu_unplug_cb(CPUHotplugState *cpu_st,
 284                        DeviceState *dev, Error **errp)
 285{
 286    AcpiCpuStatus *cdev;
 287
 288    cdev = get_cpu_status(cpu_st, dev);
 289    if (!cdev) {
 290        return;
 291    }
 292
 293    cdev->cpu = NULL;
 294}
 295
 296static const VMStateDescription vmstate_cpuhp_sts = {
 297    .name = "CPU hotplug device state",
 298    .version_id = 1,
 299    .minimum_version_id = 1,
 300    .minimum_version_id_old = 1,
 301    .fields      = (VMStateField[]) {
 302        VMSTATE_BOOL(is_inserting, AcpiCpuStatus),
 303        VMSTATE_BOOL(is_removing, AcpiCpuStatus),
 304        VMSTATE_UINT32(ost_event, AcpiCpuStatus),
 305        VMSTATE_UINT32(ost_status, AcpiCpuStatus),
 306        VMSTATE_END_OF_LIST()
 307    }
 308};
 309
 310const VMStateDescription vmstate_cpu_hotplug = {
 311    .name = "CPU hotplug state",
 312    .version_id = 1,
 313    .minimum_version_id = 1,
 314    .minimum_version_id_old = 1,
 315    .fields      = (VMStateField[]) {
 316        VMSTATE_UINT32(selector, CPUHotplugState),
 317        VMSTATE_UINT8(command, CPUHotplugState),
 318        VMSTATE_STRUCT_VARRAY_POINTER_UINT32(devs, CPUHotplugState, dev_count,
 319                                             vmstate_cpuhp_sts, AcpiCpuStatus),
 320        VMSTATE_END_OF_LIST()
 321    }
 322};
 323
 324#define CPU_NAME_FMT      "C%.03X"
 325#define CPUHP_RES_DEVICE  "PRES"
 326#define CPU_LOCK          "CPLK"
 327#define CPU_STS_METHOD    "CSTA"
 328#define CPU_SCAN_METHOD   "CSCN"
 329#define CPU_NOTIFY_METHOD "CTFY"
 330#define CPU_EJECT_METHOD  "CEJ0"
 331#define CPU_OST_METHOD    "COST"
 332#define CPU_ADDED_LIST    "CNEW"
 333
 334#define CPU_ENABLED       "CPEN"
 335#define CPU_SELECTOR      "CSEL"
 336#define CPU_COMMAND       "CCMD"
 337#define CPU_DATA          "CDAT"
 338#define CPU_INSERT_EVENT  "CINS"
 339#define CPU_REMOVE_EVENT  "CRMV"
 340#define CPU_EJECT_EVENT   "CEJ0"
 341#define CPU_FW_EJECT_EVENT "CEJF"
 342
 343void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts,
 344                    hwaddr io_base,
 345                    const char *res_root,
 346                    const char *event_handler_method)
 347{
 348    Aml *ifctx;
 349    Aml *field;
 350    Aml *method;
 351    Aml *cpu_ctrl_dev;
 352    Aml *cpus_dev;
 353    Aml *zero = aml_int(0);
 354    Aml *one = aml_int(1);
 355    Aml *sb_scope = aml_scope("_SB");
 356    MachineClass *mc = MACHINE_GET_CLASS(machine);
 357    const CPUArchIdList *arch_ids = mc->possible_cpu_arch_ids(machine);
 358    char *cphp_res_path = g_strdup_printf("%s." CPUHP_RES_DEVICE, res_root);
 359    Object *obj = object_resolve_path_type("", TYPE_ACPI_DEVICE_IF, NULL);
 360    AcpiDeviceIfClass *adevc = ACPI_DEVICE_IF_GET_CLASS(obj);
 361    AcpiDeviceIf *adev = ACPI_DEVICE_IF(obj);
 362
 363    cpu_ctrl_dev = aml_device("%s", cphp_res_path);
 364    {
 365        Aml *crs;
 366
 367        aml_append(cpu_ctrl_dev,
 368            aml_name_decl("_HID", aml_eisaid("PNP0A06")));
 369        aml_append(cpu_ctrl_dev,
 370            aml_name_decl("_UID", aml_string("CPU Hotplug resources")));
 371        aml_append(cpu_ctrl_dev, aml_mutex(CPU_LOCK, 0));
 372
 373        crs = aml_resource_template();
 374        aml_append(crs, aml_io(AML_DECODE16, io_base, io_base, 1,
 375                               ACPI_CPU_HOTPLUG_REG_LEN));
 376        aml_append(cpu_ctrl_dev, aml_name_decl("_CRS", crs));
 377
 378        /* declare CPU hotplug MMIO region with related access fields */
 379        aml_append(cpu_ctrl_dev,
 380            aml_operation_region("PRST", AML_SYSTEM_IO, aml_int(io_base),
 381                                 ACPI_CPU_HOTPLUG_REG_LEN));
 382
 383        field = aml_field("PRST", AML_BYTE_ACC, AML_NOLOCK,
 384                          AML_WRITE_AS_ZEROS);
 385        aml_append(field, aml_reserved_field(ACPI_CPU_FLAGS_OFFSET_RW * 8));
 386        /* 1 if enabled, read only */
 387        aml_append(field, aml_named_field(CPU_ENABLED, 1));
 388        /* (read) 1 if has a insert event. (write) 1 to clear event */
 389        aml_append(field, aml_named_field(CPU_INSERT_EVENT, 1));
 390        /* (read) 1 if has a remove event. (write) 1 to clear event */
 391        aml_append(field, aml_named_field(CPU_REMOVE_EVENT, 1));
 392        /* initiates device eject, write only */
 393        aml_append(field, aml_named_field(CPU_EJECT_EVENT, 1));
 394        /* tell firmware to do device eject, write only */
 395        aml_append(field, aml_named_field(CPU_FW_EJECT_EVENT, 1));
 396        aml_append(field, aml_reserved_field(3));
 397        aml_append(field, aml_named_field(CPU_COMMAND, 8));
 398        aml_append(cpu_ctrl_dev, field);
 399
 400        field = aml_field("PRST", AML_DWORD_ACC, AML_NOLOCK, AML_PRESERVE);
 401        /* CPU selector, write only */
 402        aml_append(field, aml_named_field(CPU_SELECTOR, 32));
 403        /* flags + cmd + 2byte align */
 404        aml_append(field, aml_reserved_field(4 * 8));
 405        aml_append(field, aml_named_field(CPU_DATA, 32));
 406        aml_append(cpu_ctrl_dev, field);
 407
 408        if (opts.has_legacy_cphp) {
 409            method = aml_method("_INI", 0, AML_SERIALIZED);
 410            /* switch off legacy CPU hotplug HW and use new one,
 411             * on reboot system is in new mode and writing 0
 412             * in CPU_SELECTOR selects BSP, which is NOP at
 413             * the time _INI is called */
 414            aml_append(method, aml_store(zero, aml_name(CPU_SELECTOR)));
 415            aml_append(cpu_ctrl_dev, method);
 416        }
 417    }
 418    aml_append(sb_scope, cpu_ctrl_dev);
 419
 420    cpus_dev = aml_device("\\_SB.CPUS");
 421    {
 422        int i;
 423        Aml *ctrl_lock = aml_name("%s.%s", cphp_res_path, CPU_LOCK);
 424        Aml *cpu_selector = aml_name("%s.%s", cphp_res_path, CPU_SELECTOR);
 425        Aml *is_enabled = aml_name("%s.%s", cphp_res_path, CPU_ENABLED);
 426        Aml *cpu_cmd = aml_name("%s.%s", cphp_res_path, CPU_COMMAND);
 427        Aml *cpu_data = aml_name("%s.%s", cphp_res_path, CPU_DATA);
 428        Aml *ins_evt = aml_name("%s.%s", cphp_res_path, CPU_INSERT_EVENT);
 429        Aml *rm_evt = aml_name("%s.%s", cphp_res_path, CPU_REMOVE_EVENT);
 430        Aml *ej_evt = aml_name("%s.%s", cphp_res_path, CPU_EJECT_EVENT);
 431        Aml *fw_ej_evt = aml_name("%s.%s", cphp_res_path, CPU_FW_EJECT_EVENT);
 432
 433        aml_append(cpus_dev, aml_name_decl("_HID", aml_string("ACPI0010")));
 434        aml_append(cpus_dev, aml_name_decl("_CID", aml_eisaid("PNP0A05")));
 435
 436        method = aml_method(CPU_NOTIFY_METHOD, 2, AML_NOTSERIALIZED);
 437        for (i = 0; i < arch_ids->len; i++) {
 438            Aml *cpu = aml_name(CPU_NAME_FMT, i);
 439            Aml *uid = aml_arg(0);
 440            Aml *event = aml_arg(1);
 441
 442            ifctx = aml_if(aml_equal(uid, aml_int(i)));
 443            {
 444                aml_append(ifctx, aml_notify(cpu, event));
 445            }
 446            aml_append(method, ifctx);
 447        }
 448        aml_append(cpus_dev, method);
 449
 450        method = aml_method(CPU_STS_METHOD, 1, AML_SERIALIZED);
 451        {
 452            Aml *idx = aml_arg(0);
 453            Aml *sta = aml_local(0);
 454
 455            aml_append(method, aml_acquire(ctrl_lock, 0xFFFF));
 456            aml_append(method, aml_store(idx, cpu_selector));
 457            aml_append(method, aml_store(zero, sta));
 458            ifctx = aml_if(aml_equal(is_enabled, one));
 459            {
 460                aml_append(ifctx, aml_store(aml_int(0xF), sta));
 461            }
 462            aml_append(method, ifctx);
 463            aml_append(method, aml_release(ctrl_lock));
 464            aml_append(method, aml_return(sta));
 465        }
 466        aml_append(cpus_dev, method);
 467
 468        method = aml_method(CPU_EJECT_METHOD, 1, AML_SERIALIZED);
 469        {
 470            Aml *idx = aml_arg(0);
 471
 472            aml_append(method, aml_acquire(ctrl_lock, 0xFFFF));
 473            aml_append(method, aml_store(idx, cpu_selector));
 474            if (opts.fw_unplugs_cpu) {
 475                aml_append(method, aml_store(one, fw_ej_evt));
 476                aml_append(method, aml_store(aml_int(OVMF_CPUHP_SMI_CMD),
 477                           aml_name("%s", opts.smi_path)));
 478            } else {
 479                aml_append(method, aml_store(one, ej_evt));
 480            }
 481            aml_append(method, aml_release(ctrl_lock));
 482        }
 483        aml_append(cpus_dev, method);
 484
 485        method = aml_method(CPU_SCAN_METHOD, 0, AML_SERIALIZED);
 486        {
 487            const uint8_t max_cpus_per_pass = 255;
 488            Aml *else_ctx;
 489            Aml *while_ctx, *while_ctx2;
 490            Aml *has_event = aml_local(0);
 491            Aml *dev_chk = aml_int(1);
 492            Aml *eject_req = aml_int(3);
 493            Aml *next_cpu_cmd = aml_int(CPHP_GET_NEXT_CPU_WITH_EVENT_CMD);
 494            Aml *num_added_cpus = aml_local(1);
 495            Aml *cpu_idx = aml_local(2);
 496            Aml *uid = aml_local(3);
 497            Aml *has_job = aml_local(4);
 498            Aml *new_cpus = aml_name(CPU_ADDED_LIST);
 499
 500            aml_append(method, aml_acquire(ctrl_lock, 0xFFFF));
 501
 502            /*
 503             * Windows versions newer than XP (including Windows 10/Windows
 504             * Server 2019), do support* VarPackageOp but, it is cripled to hold
 505             * the same elements number as old PackageOp.
 506             * For compatibility with Windows XP (so it won't crash) use ACPI1.0
 507             * PackageOp which can hold max 255 elements.
 508             *
 509             * use named package as old Windows don't support it in local var
 510             */
 511            aml_append(method, aml_name_decl(CPU_ADDED_LIST,
 512                                             aml_package(max_cpus_per_pass)));
 513
 514            aml_append(method, aml_store(zero, uid));
 515            aml_append(method, aml_store(one, has_job));
 516            /*
 517             * CPU_ADDED_LIST can hold limited number of elements, outer loop
 518             * allows to process CPUs in batches which let us to handle more
 519             * CPUs than CPU_ADDED_LIST can hold.
 520             */
 521            while_ctx2 = aml_while(aml_equal(has_job, one));
 522            {
 523                aml_append(while_ctx2, aml_store(zero, has_job));
 524
 525                aml_append(while_ctx2, aml_store(one, has_event));
 526                aml_append(while_ctx2, aml_store(zero, num_added_cpus));
 527
 528                /*
 529                 * Scan CPUs, till there are CPUs with events or
 530                 * CPU_ADDED_LIST capacity is exhausted
 531                 */
 532                while_ctx = aml_while(aml_land(aml_equal(has_event, one),
 533                                      aml_lless(uid, aml_int(arch_ids->len))));
 534                {
 535                     /*
 536                      * clear loop exit condition, ins_evt/rm_evt checks will
 537                      * set it to 1 while next_cpu_cmd returns a CPU with events
 538                      */
 539                     aml_append(while_ctx, aml_store(zero, has_event));
 540
 541                     aml_append(while_ctx, aml_store(uid, cpu_selector));
 542                     aml_append(while_ctx, aml_store(next_cpu_cmd, cpu_cmd));
 543
 544                     /*
 545                      * wrap around case, scan is complete, exit loop.
 546                      * It happens since events are not cleared in scan loop,
 547                      * so next_cpu_cmd continues to find already processed CPUs
 548                      */
 549                     ifctx = aml_if(aml_lless(cpu_data, uid));
 550                     {
 551                         aml_append(ifctx, aml_break());
 552                     }
 553                     aml_append(while_ctx, ifctx);
 554
 555                     /*
 556                      * if CPU_ADDED_LIST is full, exit inner loop and process
 557                      * collected CPUs
 558                      */
 559                     ifctx = aml_if(
 560                         aml_equal(num_added_cpus, aml_int(max_cpus_per_pass)));
 561                     {
 562                         aml_append(ifctx, aml_store(one, has_job));
 563                         aml_append(ifctx, aml_break());
 564                     }
 565                     aml_append(while_ctx, ifctx);
 566
 567                     aml_append(while_ctx, aml_store(cpu_data, uid));
 568                     ifctx = aml_if(aml_equal(ins_evt, one));
 569                     {
 570                         /* cache added CPUs to Notify/Wakeup later */
 571                         aml_append(ifctx, aml_store(uid,
 572                             aml_index(new_cpus, num_added_cpus)));
 573                         aml_append(ifctx, aml_increment(num_added_cpus));
 574                         aml_append(ifctx, aml_store(one, has_event));
 575                     }
 576                     aml_append(while_ctx, ifctx);
 577                     else_ctx = aml_else();
 578                     ifctx = aml_if(aml_equal(rm_evt, one));
 579                     {
 580                         aml_append(ifctx,
 581                             aml_call2(CPU_NOTIFY_METHOD, uid, eject_req));
 582                         aml_append(ifctx, aml_store(one, rm_evt));
 583                         aml_append(ifctx, aml_store(one, has_event));
 584                     }
 585                     aml_append(else_ctx, ifctx);
 586                     aml_append(while_ctx, else_ctx);
 587                     aml_append(while_ctx, aml_increment(uid));
 588                }
 589                aml_append(while_ctx2, while_ctx);
 590
 591                /*
 592                 * in case FW negotiated ICH9_LPC_SMI_F_CPU_HOTPLUG_BIT,
 593                 * make upcall to FW, so it can pull in new CPUs before
 594                 * OS is notified and wakes them up
 595                 */
 596                if (opts.smi_path) {
 597                    ifctx = aml_if(aml_lgreater(num_added_cpus, zero));
 598                    {
 599                        aml_append(ifctx, aml_store(aml_int(OVMF_CPUHP_SMI_CMD),
 600                            aml_name("%s", opts.smi_path)));
 601                    }
 602                    aml_append(while_ctx2, ifctx);
 603                }
 604
 605                /* Notify OSPM about new CPUs and clear insert events */
 606                aml_append(while_ctx2, aml_store(zero, cpu_idx));
 607                while_ctx = aml_while(aml_lless(cpu_idx, num_added_cpus));
 608                {
 609                    aml_append(while_ctx,
 610                        aml_store(aml_derefof(aml_index(new_cpus, cpu_idx)),
 611                                  uid));
 612                    aml_append(while_ctx,
 613                        aml_call2(CPU_NOTIFY_METHOD, uid, dev_chk));
 614                    aml_append(while_ctx, aml_store(uid, aml_debug()));
 615                    aml_append(while_ctx, aml_store(uid, cpu_selector));
 616                    aml_append(while_ctx, aml_store(one, ins_evt));
 617                    aml_append(while_ctx, aml_increment(cpu_idx));
 618                }
 619                aml_append(while_ctx2, while_ctx);
 620                /*
 621                 * If another batch is needed, then it will resume scanning
 622                 * exactly at -- and not after -- the last CPU that's currently
 623                 * in CPU_ADDED_LIST. In other words, the last CPU in
 624                 * CPU_ADDED_LIST is going to be re-checked. That's OK: we've
 625                 * just cleared the insert event for *all* CPUs in
 626                 * CPU_ADDED_LIST, including the last one. So the scan will
 627                 * simply seek past it.
 628                 */
 629            }
 630            aml_append(method, while_ctx2);
 631            aml_append(method, aml_release(ctrl_lock));
 632        }
 633        aml_append(cpus_dev, method);
 634
 635        method = aml_method(CPU_OST_METHOD, 4, AML_SERIALIZED);
 636        {
 637            Aml *uid = aml_arg(0);
 638            Aml *ev_cmd = aml_int(CPHP_OST_EVENT_CMD);
 639            Aml *st_cmd = aml_int(CPHP_OST_STATUS_CMD);
 640
 641            aml_append(method, aml_acquire(ctrl_lock, 0xFFFF));
 642            aml_append(method, aml_store(uid, cpu_selector));
 643            aml_append(method, aml_store(ev_cmd, cpu_cmd));
 644            aml_append(method, aml_store(aml_arg(1), cpu_data));
 645            aml_append(method, aml_store(st_cmd, cpu_cmd));
 646            aml_append(method, aml_store(aml_arg(2), cpu_data));
 647            aml_append(method, aml_release(ctrl_lock));
 648        }
 649        aml_append(cpus_dev, method);
 650
 651        /* build Processor object for each processor */
 652        for (i = 0; i < arch_ids->len; i++) {
 653            Aml *dev;
 654            Aml *uid = aml_int(i);
 655            GArray *madt_buf = g_array_new(0, 1, 1);
 656            int arch_id = arch_ids->cpus[i].arch_id;
 657
 658            if (opts.acpi_1_compatible && arch_id < 255) {
 659                dev = aml_processor(i, 0, 0, CPU_NAME_FMT, i);
 660            } else {
 661                dev = aml_device(CPU_NAME_FMT, i);
 662                aml_append(dev, aml_name_decl("_HID", aml_string("ACPI0007")));
 663                aml_append(dev, aml_name_decl("_UID", uid));
 664            }
 665
 666            method = aml_method("_STA", 0, AML_SERIALIZED);
 667            aml_append(method, aml_return(aml_call1(CPU_STS_METHOD, uid)));
 668            aml_append(dev, method);
 669
 670            /* build _MAT object */
 671            assert(adevc && adevc->madt_cpu);
 672            adevc->madt_cpu(adev, i, arch_ids, madt_buf);
 673            switch (madt_buf->data[0]) {
 674            case ACPI_APIC_PROCESSOR: {
 675                AcpiMadtProcessorApic *apic = (void *)madt_buf->data;
 676                apic->flags = cpu_to_le32(1);
 677                break;
 678            }
 679            case ACPI_APIC_LOCAL_X2APIC: {
 680                AcpiMadtProcessorX2Apic *apic = (void *)madt_buf->data;
 681                apic->flags = cpu_to_le32(1);
 682                break;
 683            }
 684            default:
 685                assert(0);
 686            }
 687            aml_append(dev, aml_name_decl("_MAT",
 688                aml_buffer(madt_buf->len, (uint8_t *)madt_buf->data)));
 689            g_array_free(madt_buf, true);
 690
 691            if (CPU(arch_ids->cpus[i].cpu) != first_cpu) {
 692                method = aml_method("_EJ0", 1, AML_NOTSERIALIZED);
 693                aml_append(method, aml_call1(CPU_EJECT_METHOD, uid));
 694                aml_append(dev, method);
 695            }
 696
 697            method = aml_method("_OST", 3, AML_SERIALIZED);
 698            aml_append(method,
 699                aml_call4(CPU_OST_METHOD, uid, aml_arg(0),
 700                          aml_arg(1), aml_arg(2))
 701            );
 702            aml_append(dev, method);
 703
 704            /* Linux guests discard SRAT info for non-present CPUs
 705             * as a result _PXM is required for all CPUs which might
 706             * be hot-plugged. For simplicity, add it for all CPUs.
 707             */
 708            if (arch_ids->cpus[i].props.has_node_id) {
 709                aml_append(dev, aml_name_decl("_PXM",
 710                           aml_int(arch_ids->cpus[i].props.node_id)));
 711            }
 712
 713            aml_append(cpus_dev, dev);
 714        }
 715    }
 716    aml_append(sb_scope, cpus_dev);
 717    aml_append(table, sb_scope);
 718
 719    method = aml_method(event_handler_method, 0, AML_NOTSERIALIZED);
 720    aml_append(method, aml_call0("\\_SB.CPUS." CPU_SCAN_METHOD));
 721    aml_append(table, method);
 722
 723    g_free(cphp_res_path);
 724}
 725