hw/acpi/cpu.c

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