xref: /openbmc/qemu/hw/acpi/cpu.c (revision e6d0c3ce689585ad8f38c826e69ee04fb2c2257c)
1 #include "qemu/osdep.h"
2 #include "hw/boards.h"
3 #include "migration/vmstate.h"
4 #include "hw/acpi/cpu.h"
5 #include "qapi/error.h"
6 #include "qapi/qapi-events-misc.h"
7 #include "trace.h"
8 #include "sysemu/numa.h"
9 
10 #define ACPI_CPU_HOTPLUG_REG_LEN 12
11 #define ACPI_CPU_SELECTOR_OFFSET_WR 0
12 #define ACPI_CPU_FLAGS_OFFSET_RW 4
13 #define ACPI_CPU_CMD_OFFSET_WR 5
14 #define ACPI_CPU_CMD_DATA_OFFSET_RW 8
15 #define ACPI_CPU_CMD_DATA2_OFFSET_R 0
16 
17 enum {
18     CPHP_GET_NEXT_CPU_WITH_EVENT_CMD = 0,
19     CPHP_OST_EVENT_CMD = 1,
20     CPHP_OST_STATUS_CMD = 2,
21     CPHP_CMD_MAX
22 };
23 
24 static ACPIOSTInfo *acpi_cpu_device_status(int idx, AcpiCpuStatus *cdev)
25 {
26     ACPIOSTInfo *info = g_new0(ACPIOSTInfo, 1);
27 
28     info->slot_type = ACPI_SLOT_TYPE_CPU;
29     info->slot = g_strdup_printf("%d", idx);
30     info->source = cdev->ost_event;
31     info->status = cdev->ost_status;
32     if (cdev->cpu) {
33         DeviceState *dev = DEVICE(cdev->cpu);
34         if (dev->id) {
35             info->device = g_strdup(dev->id);
36             info->has_device = true;
37         }
38     }
39     return info;
40 }
41 
42 void acpi_cpu_ospm_status(CPUHotplugState *cpu_st, ACPIOSTInfoList ***list)
43 {
44     int i;
45 
46     for (i = 0; i < cpu_st->dev_count; i++) {
47         ACPIOSTInfoList *elem = g_new0(ACPIOSTInfoList, 1);
48         elem->value = acpi_cpu_device_status(i, &cpu_st->devs[i]);
49         elem->next = NULL;
50         **list = elem;
51         *list = &elem->next;
52     }
53 }
54 
55 static uint64_t cpu_hotplug_rd(void *opaque, hwaddr addr, unsigned size)
56 {
57     uint64_t val = 0;
58     CPUHotplugState *cpu_st = opaque;
59     AcpiCpuStatus *cdev;
60 
61     if (cpu_st->selector >= cpu_st->dev_count) {
62         return val;
63     }
64 
65     cdev = &cpu_st->devs[cpu_st->selector];
66     switch (addr) {
67     case ACPI_CPU_FLAGS_OFFSET_RW: /* pack and return is_* fields */
68         val |= cdev->cpu ? 1 : 0;
69         val |= cdev->is_inserting ? 2 : 0;
70         val |= cdev->is_removing  ? 4 : 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         default:
79            break;
80         }
81         trace_cpuhp_acpi_read_cmd_data(cpu_st->selector, val);
82         break;
83     case ACPI_CPU_CMD_DATA2_OFFSET_R:
84         switch (cpu_st->command) {
85         case CPHP_GET_NEXT_CPU_WITH_EVENT_CMD:
86            val = 0;
87            break;
88         default:
89            break;
90         }
91         trace_cpuhp_acpi_read_cmd_data2(cpu_st->selector, val);
92         break;
93     default:
94         break;
95     }
96     return val;
97 }
98 
99 static void cpu_hotplug_wr(void *opaque, hwaddr addr, uint64_t data,
100                            unsigned int size)
101 {
102     CPUHotplugState *cpu_st = opaque;
103     AcpiCpuStatus *cdev;
104     ACPIOSTInfo *info;
105 
106     assert(cpu_st->dev_count);
107 
108     if (addr) {
109         if (cpu_st->selector >= cpu_st->dev_count) {
110             trace_cpuhp_acpi_invalid_idx_selected(cpu_st->selector);
111             return;
112         }
113     }
114 
115     switch (addr) {
116     case ACPI_CPU_SELECTOR_OFFSET_WR: /* current CPU selector */
117         cpu_st->selector = data;
118         trace_cpuhp_acpi_write_idx(cpu_st->selector);
119         break;
120     case ACPI_CPU_FLAGS_OFFSET_RW: /* set is_* fields  */
121         cdev = &cpu_st->devs[cpu_st->selector];
122         if (data & 2) { /* clear insert event */
123             cdev->is_inserting = false;
124             trace_cpuhp_acpi_clear_inserting_evt(cpu_st->selector);
125         } else if (data & 4) { /* clear remove event */
126             cdev->is_removing = false;
127             trace_cpuhp_acpi_clear_remove_evt(cpu_st->selector);
128         } else if (data & 8) {
129             DeviceState *dev = NULL;
130             HotplugHandler *hotplug_ctrl = NULL;
131 
132             if (!cdev->cpu || cdev->cpu == first_cpu) {
133                 trace_cpuhp_acpi_ejecting_invalid_cpu(cpu_st->selector);
134                 break;
135             }
136 
137             trace_cpuhp_acpi_ejecting_cpu(cpu_st->selector);
138             dev = DEVICE(cdev->cpu);
139             hotplug_ctrl = qdev_get_hotplug_handler(dev);
140             hotplug_handler_unplug(hotplug_ctrl, dev, NULL);
141             object_unparent(OBJECT(dev));
142         }
143         break;
144     case ACPI_CPU_CMD_OFFSET_WR:
145         trace_cpuhp_acpi_write_cmd(cpu_st->selector, data);
146         if (data < CPHP_CMD_MAX) {
147             cpu_st->command = data;
148             if (cpu_st->command == CPHP_GET_NEXT_CPU_WITH_EVENT_CMD) {
149                 uint32_t iter = cpu_st->selector;
150 
151                 do {
152                     cdev = &cpu_st->devs[iter];
153                     if (cdev->is_inserting || cdev->is_removing) {
154                         cpu_st->selector = iter;
155                         trace_cpuhp_acpi_cpu_has_events(cpu_st->selector,
156                             cdev->is_inserting, cdev->is_removing);
157                         break;
158                     }
159                     iter = iter + 1 < cpu_st->dev_count ? iter + 1 : 0;
160                 } while (iter != cpu_st->selector);
161             }
162         }
163         break;
164     case ACPI_CPU_CMD_DATA_OFFSET_RW:
165         switch (cpu_st->command) {
166         case CPHP_OST_EVENT_CMD: {
167            cdev = &cpu_st->devs[cpu_st->selector];
168            cdev->ost_event = data;
169            trace_cpuhp_acpi_write_ost_ev(cpu_st->selector, cdev->ost_event);
170            break;
171         }
172         case CPHP_OST_STATUS_CMD: {
173            cdev = &cpu_st->devs[cpu_st->selector];
174            cdev->ost_status = data;
175            info = acpi_cpu_device_status(cpu_st->selector, cdev);
176            qapi_event_send_acpi_device_ost(info);
177            qapi_free_ACPIOSTInfo(info);
178            trace_cpuhp_acpi_write_ost_status(cpu_st->selector,
179                                              cdev->ost_status);
180            break;
181         }
182         default:
183            break;
184         }
185         break;
186     default:
187         break;
188     }
189 }
190 
191 static const MemoryRegionOps cpu_hotplug_ops = {
192     .read = cpu_hotplug_rd,
193     .write = cpu_hotplug_wr,
194     .endianness = DEVICE_LITTLE_ENDIAN,
195     .valid = {
196         .min_access_size = 1,
197         .max_access_size = 4,
198     },
199 };
200 
201 void cpu_hotplug_hw_init(MemoryRegion *as, Object *owner,
202                          CPUHotplugState *state, hwaddr base_addr)
203 {
204     MachineState *machine = MACHINE(qdev_get_machine());
205     MachineClass *mc = MACHINE_GET_CLASS(machine);
206     const CPUArchIdList *id_list;
207     int i;
208 
209     assert(mc->possible_cpu_arch_ids);
210     id_list = mc->possible_cpu_arch_ids(machine);
211     state->dev_count = id_list->len;
212     state->devs = g_new0(typeof(*state->devs), state->dev_count);
213     for (i = 0; i < id_list->len; i++) {
214         state->devs[i].cpu =  CPU(id_list->cpus[i].cpu);
215         state->devs[i].arch_id = id_list->cpus[i].arch_id;
216     }
217     memory_region_init_io(&state->ctrl_reg, owner, &cpu_hotplug_ops, state,
218                           "acpi-mem-hotplug", ACPI_CPU_HOTPLUG_REG_LEN);
219     memory_region_add_subregion(as, base_addr, &state->ctrl_reg);
220 }
221 
222 static AcpiCpuStatus *get_cpu_status(CPUHotplugState *cpu_st, DeviceState *dev)
223 {
224     CPUClass *k = CPU_GET_CLASS(dev);
225     uint64_t cpu_arch_id = k->get_arch_id(CPU(dev));
226     int i;
227 
228     for (i = 0; i < cpu_st->dev_count; i++) {
229         if (cpu_arch_id == cpu_st->devs[i].arch_id) {
230             return &cpu_st->devs[i];
231         }
232     }
233     return NULL;
234 }
235 
236 void acpi_cpu_plug_cb(HotplugHandler *hotplug_dev,
237                       CPUHotplugState *cpu_st, DeviceState *dev, Error **errp)
238 {
239     AcpiCpuStatus *cdev;
240 
241     cdev = get_cpu_status(cpu_st, dev);
242     if (!cdev) {
243         return;
244     }
245 
246     cdev->cpu = CPU(dev);
247     if (dev->hotplugged) {
248         cdev->is_inserting = true;
249         acpi_send_event(DEVICE(hotplug_dev), ACPI_CPU_HOTPLUG_STATUS);
250     }
251 }
252 
253 void acpi_cpu_unplug_request_cb(HotplugHandler *hotplug_dev,
254                                 CPUHotplugState *cpu_st,
255                                 DeviceState *dev, Error **errp)
256 {
257     AcpiCpuStatus *cdev;
258 
259     cdev = get_cpu_status(cpu_st, dev);
260     if (!cdev) {
261         return;
262     }
263 
264     cdev->is_removing = true;
265     acpi_send_event(DEVICE(hotplug_dev), ACPI_CPU_HOTPLUG_STATUS);
266 }
267 
268 void acpi_cpu_unplug_cb(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->cpu = NULL;
279 }
280 
281 static const VMStateDescription vmstate_cpuhp_sts = {
282     .name = "CPU hotplug device state",
283     .version_id = 1,
284     .minimum_version_id = 1,
285     .minimum_version_id_old = 1,
286     .fields      = (VMStateField[]) {
287         VMSTATE_BOOL(is_inserting, AcpiCpuStatus),
288         VMSTATE_BOOL(is_removing, AcpiCpuStatus),
289         VMSTATE_UINT32(ost_event, AcpiCpuStatus),
290         VMSTATE_UINT32(ost_status, AcpiCpuStatus),
291         VMSTATE_END_OF_LIST()
292     }
293 };
294 
295 const VMStateDescription vmstate_cpu_hotplug = {
296     .name = "CPU hotplug state",
297     .version_id = 1,
298     .minimum_version_id = 1,
299     .minimum_version_id_old = 1,
300     .fields      = (VMStateField[]) {
301         VMSTATE_UINT32(selector, CPUHotplugState),
302         VMSTATE_UINT8(command, CPUHotplugState),
303         VMSTATE_STRUCT_VARRAY_POINTER_UINT32(devs, CPUHotplugState, dev_count,
304                                              vmstate_cpuhp_sts, AcpiCpuStatus),
305         VMSTATE_END_OF_LIST()
306     }
307 };
308 
309 #define CPU_NAME_FMT      "C%.03X"
310 #define CPUHP_RES_DEVICE  "PRES"
311 #define CPU_LOCK          "CPLK"
312 #define CPU_STS_METHOD    "CSTA"
313 #define CPU_SCAN_METHOD   "CSCN"
314 #define CPU_NOTIFY_METHOD "CTFY"
315 #define CPU_EJECT_METHOD  "CEJ0"
316 #define CPU_OST_METHOD    "COST"
317 
318 #define CPU_ENABLED       "CPEN"
319 #define CPU_SELECTOR      "CSEL"
320 #define CPU_COMMAND       "CCMD"
321 #define CPU_DATA          "CDAT"
322 #define CPU_INSERT_EVENT  "CINS"
323 #define CPU_REMOVE_EVENT  "CRMV"
324 #define CPU_EJECT_EVENT   "CEJ0"
325 
326 void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts,
327                     hwaddr io_base,
328                     const char *res_root,
329                     const char *event_handler_method)
330 {
331     Aml *ifctx;
332     Aml *field;
333     Aml *method;
334     Aml *cpu_ctrl_dev;
335     Aml *cpus_dev;
336     Aml *zero = aml_int(0);
337     Aml *one = aml_int(1);
338     Aml *sb_scope = aml_scope("_SB");
339     MachineClass *mc = MACHINE_GET_CLASS(machine);
340     const CPUArchIdList *arch_ids = mc->possible_cpu_arch_ids(machine);
341     char *cphp_res_path = g_strdup_printf("%s." CPUHP_RES_DEVICE, res_root);
342     Object *obj = object_resolve_path_type("", TYPE_ACPI_DEVICE_IF, NULL);
343     AcpiDeviceIfClass *adevc = ACPI_DEVICE_IF_GET_CLASS(obj);
344     AcpiDeviceIf *adev = ACPI_DEVICE_IF(obj);
345 
346     cpu_ctrl_dev = aml_device("%s", cphp_res_path);
347     {
348         Aml *crs;
349 
350         aml_append(cpu_ctrl_dev,
351             aml_name_decl("_HID", aml_eisaid("PNP0A06")));
352         aml_append(cpu_ctrl_dev,
353             aml_name_decl("_UID", aml_string("CPU Hotplug resources")));
354         aml_append(cpu_ctrl_dev, aml_mutex(CPU_LOCK, 0));
355 
356         crs = aml_resource_template();
357         aml_append(crs, aml_io(AML_DECODE16, io_base, io_base, 1,
358                                ACPI_CPU_HOTPLUG_REG_LEN));
359         aml_append(cpu_ctrl_dev, aml_name_decl("_CRS", crs));
360 
361         /* declare CPU hotplug MMIO region with related access fields */
362         aml_append(cpu_ctrl_dev,
363             aml_operation_region("PRST", AML_SYSTEM_IO, aml_int(io_base),
364                                  ACPI_CPU_HOTPLUG_REG_LEN));
365 
366         field = aml_field("PRST", AML_BYTE_ACC, AML_NOLOCK,
367                           AML_WRITE_AS_ZEROS);
368         aml_append(field, aml_reserved_field(ACPI_CPU_FLAGS_OFFSET_RW * 8));
369         /* 1 if enabled, read only */
370         aml_append(field, aml_named_field(CPU_ENABLED, 1));
371         /* (read) 1 if has a insert event. (write) 1 to clear event */
372         aml_append(field, aml_named_field(CPU_INSERT_EVENT, 1));
373         /* (read) 1 if has a remove event. (write) 1 to clear event */
374         aml_append(field, aml_named_field(CPU_REMOVE_EVENT, 1));
375         /* initiates device eject, write only */
376         aml_append(field, aml_named_field(CPU_EJECT_EVENT, 1));
377         aml_append(field, aml_reserved_field(4));
378         aml_append(field, aml_named_field(CPU_COMMAND, 8));
379         aml_append(cpu_ctrl_dev, field);
380 
381         field = aml_field("PRST", AML_DWORD_ACC, AML_NOLOCK, AML_PRESERVE);
382         /* CPU selector, write only */
383         aml_append(field, aml_named_field(CPU_SELECTOR, 32));
384         /* flags + cmd + 2byte align */
385         aml_append(field, aml_reserved_field(4 * 8));
386         aml_append(field, aml_named_field(CPU_DATA, 32));
387         aml_append(cpu_ctrl_dev, field);
388 
389         if (opts.has_legacy_cphp) {
390             method = aml_method("_INI", 0, AML_SERIALIZED);
391             /* switch off legacy CPU hotplug HW and use new one,
392              * on reboot system is in new mode and writing 0
393              * in CPU_SELECTOR selects BSP, which is NOP at
394              * the time _INI is called */
395             aml_append(method, aml_store(zero, aml_name(CPU_SELECTOR)));
396             aml_append(cpu_ctrl_dev, method);
397         }
398     }
399     aml_append(sb_scope, cpu_ctrl_dev);
400 
401     cpus_dev = aml_device("\\_SB.CPUS");
402     {
403         int i;
404         Aml *ctrl_lock = aml_name("%s.%s", cphp_res_path, CPU_LOCK);
405         Aml *cpu_selector = aml_name("%s.%s", cphp_res_path, CPU_SELECTOR);
406         Aml *is_enabled = aml_name("%s.%s", cphp_res_path, CPU_ENABLED);
407         Aml *cpu_cmd = aml_name("%s.%s", cphp_res_path, CPU_COMMAND);
408         Aml *cpu_data = aml_name("%s.%s", cphp_res_path, CPU_DATA);
409         Aml *ins_evt = aml_name("%s.%s", cphp_res_path, CPU_INSERT_EVENT);
410         Aml *rm_evt = aml_name("%s.%s", cphp_res_path, CPU_REMOVE_EVENT);
411         Aml *ej_evt = aml_name("%s.%s", cphp_res_path, CPU_EJECT_EVENT);
412 
413         aml_append(cpus_dev, aml_name_decl("_HID", aml_string("ACPI0010")));
414         aml_append(cpus_dev, aml_name_decl("_CID", aml_eisaid("PNP0A05")));
415 
416         method = aml_method(CPU_NOTIFY_METHOD, 2, AML_NOTSERIALIZED);
417         for (i = 0; i < arch_ids->len; i++) {
418             Aml *cpu = aml_name(CPU_NAME_FMT, i);
419             Aml *uid = aml_arg(0);
420             Aml *event = aml_arg(1);
421 
422             ifctx = aml_if(aml_equal(uid, aml_int(i)));
423             {
424                 aml_append(ifctx, aml_notify(cpu, event));
425             }
426             aml_append(method, ifctx);
427         }
428         aml_append(cpus_dev, method);
429 
430         method = aml_method(CPU_STS_METHOD, 1, AML_SERIALIZED);
431         {
432             Aml *idx = aml_arg(0);
433             Aml *sta = aml_local(0);
434 
435             aml_append(method, aml_acquire(ctrl_lock, 0xFFFF));
436             aml_append(method, aml_store(idx, cpu_selector));
437             aml_append(method, aml_store(zero, sta));
438             ifctx = aml_if(aml_equal(is_enabled, one));
439             {
440                 aml_append(ifctx, aml_store(aml_int(0xF), sta));
441             }
442             aml_append(method, ifctx);
443             aml_append(method, aml_release(ctrl_lock));
444             aml_append(method, aml_return(sta));
445         }
446         aml_append(cpus_dev, method);
447 
448         method = aml_method(CPU_EJECT_METHOD, 1, AML_SERIALIZED);
449         {
450             Aml *idx = aml_arg(0);
451 
452             aml_append(method, aml_acquire(ctrl_lock, 0xFFFF));
453             aml_append(method, aml_store(idx, cpu_selector));
454             aml_append(method, aml_store(one, ej_evt));
455             aml_append(method, aml_release(ctrl_lock));
456         }
457         aml_append(cpus_dev, method);
458 
459         method = aml_method(CPU_SCAN_METHOD, 0, AML_SERIALIZED);
460         {
461             Aml *else_ctx;
462             Aml *while_ctx;
463             Aml *has_event = aml_local(0);
464             Aml *dev_chk = aml_int(1);
465             Aml *eject_req = aml_int(3);
466             Aml *next_cpu_cmd = aml_int(CPHP_GET_NEXT_CPU_WITH_EVENT_CMD);
467 
468             aml_append(method, aml_acquire(ctrl_lock, 0xFFFF));
469             aml_append(method, aml_store(one, has_event));
470             while_ctx = aml_while(aml_equal(has_event, one));
471             {
472                  /* clear loop exit condition, ins_evt/rm_evt checks
473                   * will set it to 1 while next_cpu_cmd returns a CPU
474                   * with events */
475                  aml_append(while_ctx, aml_store(zero, has_event));
476                  aml_append(while_ctx, aml_store(next_cpu_cmd, cpu_cmd));
477                  ifctx = aml_if(aml_equal(ins_evt, one));
478                  {
479                      aml_append(ifctx,
480                          aml_call2(CPU_NOTIFY_METHOD, cpu_data, dev_chk));
481                      aml_append(ifctx, aml_store(one, ins_evt));
482                      aml_append(ifctx, aml_store(one, has_event));
483                  }
484                  aml_append(while_ctx, ifctx);
485                  else_ctx = aml_else();
486                  ifctx = aml_if(aml_equal(rm_evt, one));
487                  {
488                      aml_append(ifctx,
489                          aml_call2(CPU_NOTIFY_METHOD, cpu_data, eject_req));
490                      aml_append(ifctx, aml_store(one, rm_evt));
491                      aml_append(ifctx, aml_store(one, has_event));
492                  }
493                  aml_append(else_ctx, ifctx);
494                  aml_append(while_ctx, else_ctx);
495             }
496             aml_append(method, while_ctx);
497             aml_append(method, aml_release(ctrl_lock));
498         }
499         aml_append(cpus_dev, method);
500 
501         method = aml_method(CPU_OST_METHOD, 4, AML_SERIALIZED);
502         {
503             Aml *uid = aml_arg(0);
504             Aml *ev_cmd = aml_int(CPHP_OST_EVENT_CMD);
505             Aml *st_cmd = aml_int(CPHP_OST_STATUS_CMD);
506 
507             aml_append(method, aml_acquire(ctrl_lock, 0xFFFF));
508             aml_append(method, aml_store(uid, cpu_selector));
509             aml_append(method, aml_store(ev_cmd, cpu_cmd));
510             aml_append(method, aml_store(aml_arg(1), cpu_data));
511             aml_append(method, aml_store(st_cmd, cpu_cmd));
512             aml_append(method, aml_store(aml_arg(2), cpu_data));
513             aml_append(method, aml_release(ctrl_lock));
514         }
515         aml_append(cpus_dev, method);
516 
517         /* build Processor object for each processor */
518         for (i = 0; i < arch_ids->len; i++) {
519             Aml *dev;
520             Aml *uid = aml_int(i);
521             GArray *madt_buf = g_array_new(0, 1, 1);
522             int arch_id = arch_ids->cpus[i].arch_id;
523 
524             if (opts.acpi_1_compatible && arch_id < 255) {
525                 dev = aml_processor(i, 0, 0, CPU_NAME_FMT, i);
526             } else {
527                 dev = aml_device(CPU_NAME_FMT, i);
528                 aml_append(dev, aml_name_decl("_HID", aml_string("ACPI0007")));
529                 aml_append(dev, aml_name_decl("_UID", uid));
530             }
531 
532             method = aml_method("_STA", 0, AML_SERIALIZED);
533             aml_append(method, aml_return(aml_call1(CPU_STS_METHOD, uid)));
534             aml_append(dev, method);
535 
536             /* build _MAT object */
537             assert(adevc && adevc->madt_cpu);
538             adevc->madt_cpu(adev, i, arch_ids, madt_buf);
539             switch (madt_buf->data[0]) {
540             case ACPI_APIC_PROCESSOR: {
541                 AcpiMadtProcessorApic *apic = (void *)madt_buf->data;
542                 apic->flags = cpu_to_le32(1);
543                 break;
544             }
545             case ACPI_APIC_LOCAL_X2APIC: {
546                 AcpiMadtProcessorX2Apic *apic = (void *)madt_buf->data;
547                 apic->flags = cpu_to_le32(1);
548                 break;
549             }
550             default:
551                 assert(0);
552             }
553             aml_append(dev, aml_name_decl("_MAT",
554                 aml_buffer(madt_buf->len, (uint8_t *)madt_buf->data)));
555             g_array_free(madt_buf, true);
556 
557             if (CPU(arch_ids->cpus[i].cpu) != first_cpu) {
558                 method = aml_method("_EJ0", 1, AML_NOTSERIALIZED);
559                 aml_append(method, aml_call1(CPU_EJECT_METHOD, uid));
560                 aml_append(dev, method);
561             }
562 
563             method = aml_method("_OST", 3, AML_SERIALIZED);
564             aml_append(method,
565                 aml_call4(CPU_OST_METHOD, uid, aml_arg(0),
566                           aml_arg(1), aml_arg(2))
567             );
568             aml_append(dev, method);
569 
570             /* Linux guests discard SRAT info for non-present CPUs
571              * as a result _PXM is required for all CPUs which might
572              * be hot-plugged. For simplicity, add it for all CPUs.
573              */
574             if (arch_ids->cpus[i].props.has_node_id) {
575                 aml_append(dev, aml_name_decl("_PXM",
576                            aml_int(arch_ids->cpus[i].props.node_id)));
577             }
578 
579             aml_append(cpus_dev, dev);
580         }
581     }
582     aml_append(sb_scope, cpus_dev);
583     aml_append(table, sb_scope);
584 
585     method = aml_method(event_handler_method, 0, AML_NOTSERIALIZED);
586     aml_append(method, aml_call0("\\_SB.CPUS." CPU_SCAN_METHOD));
587     aml_append(table, method);
588 
589     g_free(cphp_res_path);
590 }
591