xref: /openbmc/qemu/hw/acpi/cpu.c (revision ebe15582)
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 
16 enum {
17     CPHP_GET_NEXT_CPU_WITH_EVENT_CMD = 0,
18     CPHP_OST_EVENT_CMD = 1,
19     CPHP_OST_STATUS_CMD = 2,
20     CPHP_CMD_MAX
21 };
22 
23 static ACPIOSTInfo *acpi_cpu_device_status(int idx, AcpiCpuStatus *cdev)
24 {
25     ACPIOSTInfo *info = g_new0(ACPIOSTInfo, 1);
26 
27     info->slot_type = ACPI_SLOT_TYPE_CPU;
28     info->slot = g_strdup_printf("%d", idx);
29     info->source = cdev->ost_event;
30     info->status = cdev->ost_status;
31     if (cdev->cpu) {
32         DeviceState *dev = DEVICE(cdev->cpu);
33         if (dev->id) {
34             info->device = g_strdup(dev->id);
35             info->has_device = true;
36         }
37     }
38     return info;
39 }
40 
41 void acpi_cpu_ospm_status(CPUHotplugState *cpu_st, ACPIOSTInfoList ***list)
42 {
43     int i;
44 
45     for (i = 0; i < cpu_st->dev_count; i++) {
46         ACPIOSTInfoList *elem = g_new0(ACPIOSTInfoList, 1);
47         elem->value = acpi_cpu_device_status(i, &cpu_st->devs[i]);
48         elem->next = NULL;
49         **list = elem;
50         *list = &elem->next;
51     }
52 }
53 
54 static 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         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         default:
78            break;
79         }
80         trace_cpuhp_acpi_read_cmd_data(cpu_st->selector, val);
81         break;
82     default:
83         break;
84     }
85     return val;
86 }
87 
88 static void cpu_hotplug_wr(void *opaque, hwaddr addr, uint64_t data,
89                            unsigned int size)
90 {
91     CPUHotplugState *cpu_st = opaque;
92     AcpiCpuStatus *cdev;
93     ACPIOSTInfo *info;
94 
95     assert(cpu_st->dev_count);
96 
97     if (addr) {
98         if (cpu_st->selector >= cpu_st->dev_count) {
99             trace_cpuhp_acpi_invalid_idx_selected(cpu_st->selector);
100             return;
101         }
102     }
103 
104     switch (addr) {
105     case ACPI_CPU_SELECTOR_OFFSET_WR: /* current CPU selector */
106         cpu_st->selector = data;
107         trace_cpuhp_acpi_write_idx(cpu_st->selector);
108         break;
109     case ACPI_CPU_FLAGS_OFFSET_RW: /* set is_* fields  */
110         cdev = &cpu_st->devs[cpu_st->selector];
111         if (data & 2) { /* clear insert event */
112             cdev->is_inserting = false;
113             trace_cpuhp_acpi_clear_inserting_evt(cpu_st->selector);
114         } else if (data & 4) { /* clear remove event */
115             cdev->is_removing = false;
116             trace_cpuhp_acpi_clear_remove_evt(cpu_st->selector);
117         } else if (data & 8) {
118             DeviceState *dev = NULL;
119             HotplugHandler *hotplug_ctrl = NULL;
120 
121             if (!cdev->cpu || cdev->cpu == first_cpu) {
122                 trace_cpuhp_acpi_ejecting_invalid_cpu(cpu_st->selector);
123                 break;
124             }
125 
126             trace_cpuhp_acpi_ejecting_cpu(cpu_st->selector);
127             dev = DEVICE(cdev->cpu);
128             hotplug_ctrl = qdev_get_hotplug_handler(dev);
129             hotplug_handler_unplug(hotplug_ctrl, dev, NULL);
130             object_unparent(OBJECT(dev));
131         }
132         break;
133     case ACPI_CPU_CMD_OFFSET_WR:
134         trace_cpuhp_acpi_write_cmd(cpu_st->selector, data);
135         if (data < CPHP_CMD_MAX) {
136             cpu_st->command = data;
137             if (cpu_st->command == CPHP_GET_NEXT_CPU_WITH_EVENT_CMD) {
138                 uint32_t iter = cpu_st->selector;
139 
140                 do {
141                     cdev = &cpu_st->devs[iter];
142                     if (cdev->is_inserting || cdev->is_removing) {
143                         cpu_st->selector = iter;
144                         trace_cpuhp_acpi_cpu_has_events(cpu_st->selector,
145                             cdev->is_inserting, cdev->is_removing);
146                         break;
147                     }
148                     iter = iter + 1 < cpu_st->dev_count ? iter + 1 : 0;
149                 } while (iter != cpu_st->selector);
150             }
151         }
152         break;
153     case ACPI_CPU_CMD_DATA_OFFSET_RW:
154         switch (cpu_st->command) {
155         case CPHP_OST_EVENT_CMD: {
156            cdev = &cpu_st->devs[cpu_st->selector];
157            cdev->ost_event = data;
158            trace_cpuhp_acpi_write_ost_ev(cpu_st->selector, cdev->ost_event);
159            break;
160         }
161         case CPHP_OST_STATUS_CMD: {
162            cdev = &cpu_st->devs[cpu_st->selector];
163            cdev->ost_status = data;
164            info = acpi_cpu_device_status(cpu_st->selector, cdev);
165            qapi_event_send_acpi_device_ost(info);
166            qapi_free_ACPIOSTInfo(info);
167            trace_cpuhp_acpi_write_ost_status(cpu_st->selector,
168                                              cdev->ost_status);
169            break;
170         }
171         default:
172            break;
173         }
174         break;
175     default:
176         break;
177     }
178 }
179 
180 static const MemoryRegionOps cpu_hotplug_ops = {
181     .read = cpu_hotplug_rd,
182     .write = cpu_hotplug_wr,
183     .endianness = DEVICE_LITTLE_ENDIAN,
184     .valid = {
185         .min_access_size = 1,
186         .max_access_size = 4,
187     },
188 };
189 
190 void cpu_hotplug_hw_init(MemoryRegion *as, Object *owner,
191                          CPUHotplugState *state, hwaddr base_addr)
192 {
193     MachineState *machine = MACHINE(qdev_get_machine());
194     MachineClass *mc = MACHINE_GET_CLASS(machine);
195     const CPUArchIdList *id_list;
196     int i;
197 
198     assert(mc->possible_cpu_arch_ids);
199     id_list = mc->possible_cpu_arch_ids(machine);
200     state->dev_count = id_list->len;
201     state->devs = g_new0(typeof(*state->devs), state->dev_count);
202     for (i = 0; i < id_list->len; i++) {
203         state->devs[i].cpu =  CPU(id_list->cpus[i].cpu);
204         state->devs[i].arch_id = id_list->cpus[i].arch_id;
205     }
206     memory_region_init_io(&state->ctrl_reg, owner, &cpu_hotplug_ops, state,
207                           "acpi-mem-hotplug", ACPI_CPU_HOTPLUG_REG_LEN);
208     memory_region_add_subregion(as, base_addr, &state->ctrl_reg);
209 }
210 
211 static AcpiCpuStatus *get_cpu_status(CPUHotplugState *cpu_st, DeviceState *dev)
212 {
213     CPUClass *k = CPU_GET_CLASS(dev);
214     uint64_t cpu_arch_id = k->get_arch_id(CPU(dev));
215     int i;
216 
217     for (i = 0; i < cpu_st->dev_count; i++) {
218         if (cpu_arch_id == cpu_st->devs[i].arch_id) {
219             return &cpu_st->devs[i];
220         }
221     }
222     return NULL;
223 }
224 
225 void acpi_cpu_plug_cb(HotplugHandler *hotplug_dev,
226                       CPUHotplugState *cpu_st, DeviceState *dev, Error **errp)
227 {
228     AcpiCpuStatus *cdev;
229 
230     cdev = get_cpu_status(cpu_st, dev);
231     if (!cdev) {
232         return;
233     }
234 
235     cdev->cpu = CPU(dev);
236     if (dev->hotplugged) {
237         cdev->is_inserting = true;
238         acpi_send_event(DEVICE(hotplug_dev), ACPI_CPU_HOTPLUG_STATUS);
239     }
240 }
241 
242 void acpi_cpu_unplug_request_cb(HotplugHandler *hotplug_dev,
243                                 CPUHotplugState *cpu_st,
244                                 DeviceState *dev, Error **errp)
245 {
246     AcpiCpuStatus *cdev;
247 
248     cdev = get_cpu_status(cpu_st, dev);
249     if (!cdev) {
250         return;
251     }
252 
253     cdev->is_removing = true;
254     acpi_send_event(DEVICE(hotplug_dev), ACPI_CPU_HOTPLUG_STATUS);
255 }
256 
257 void acpi_cpu_unplug_cb(CPUHotplugState *cpu_st,
258                         DeviceState *dev, Error **errp)
259 {
260     AcpiCpuStatus *cdev;
261 
262     cdev = get_cpu_status(cpu_st, dev);
263     if (!cdev) {
264         return;
265     }
266 
267     cdev->cpu = NULL;
268 }
269 
270 static const VMStateDescription vmstate_cpuhp_sts = {
271     .name = "CPU hotplug device state",
272     .version_id = 1,
273     .minimum_version_id = 1,
274     .minimum_version_id_old = 1,
275     .fields      = (VMStateField[]) {
276         VMSTATE_BOOL(is_inserting, AcpiCpuStatus),
277         VMSTATE_BOOL(is_removing, AcpiCpuStatus),
278         VMSTATE_UINT32(ost_event, AcpiCpuStatus),
279         VMSTATE_UINT32(ost_status, AcpiCpuStatus),
280         VMSTATE_END_OF_LIST()
281     }
282 };
283 
284 const VMStateDescription vmstate_cpu_hotplug = {
285     .name = "CPU hotplug state",
286     .version_id = 1,
287     .minimum_version_id = 1,
288     .minimum_version_id_old = 1,
289     .fields      = (VMStateField[]) {
290         VMSTATE_UINT32(selector, CPUHotplugState),
291         VMSTATE_UINT8(command, CPUHotplugState),
292         VMSTATE_STRUCT_VARRAY_POINTER_UINT32(devs, CPUHotplugState, dev_count,
293                                              vmstate_cpuhp_sts, AcpiCpuStatus),
294         VMSTATE_END_OF_LIST()
295     }
296 };
297 
298 #define CPU_NAME_FMT      "C%.03X"
299 #define CPUHP_RES_DEVICE  "PRES"
300 #define CPU_LOCK          "CPLK"
301 #define CPU_STS_METHOD    "CSTA"
302 #define CPU_SCAN_METHOD   "CSCN"
303 #define CPU_NOTIFY_METHOD "CTFY"
304 #define CPU_EJECT_METHOD  "CEJ0"
305 #define CPU_OST_METHOD    "COST"
306 
307 #define CPU_ENABLED       "CPEN"
308 #define CPU_SELECTOR      "CSEL"
309 #define CPU_COMMAND       "CCMD"
310 #define CPU_DATA          "CDAT"
311 #define CPU_INSERT_EVENT  "CINS"
312 #define CPU_REMOVE_EVENT  "CRMV"
313 #define CPU_EJECT_EVENT   "CEJ0"
314 
315 void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts,
316                     hwaddr io_base,
317                     const char *res_root,
318                     const char *event_handler_method)
319 {
320     Aml *ifctx;
321     Aml *field;
322     Aml *method;
323     Aml *cpu_ctrl_dev;
324     Aml *cpus_dev;
325     Aml *zero = aml_int(0);
326     Aml *one = aml_int(1);
327     Aml *sb_scope = aml_scope("_SB");
328     MachineClass *mc = MACHINE_GET_CLASS(machine);
329     const CPUArchIdList *arch_ids = mc->possible_cpu_arch_ids(machine);
330     char *cphp_res_path = g_strdup_printf("%s." CPUHP_RES_DEVICE, res_root);
331     Object *obj = object_resolve_path_type("", TYPE_ACPI_DEVICE_IF, NULL);
332     AcpiDeviceIfClass *adevc = ACPI_DEVICE_IF_GET_CLASS(obj);
333     AcpiDeviceIf *adev = ACPI_DEVICE_IF(obj);
334 
335     cpu_ctrl_dev = aml_device("%s", cphp_res_path);
336     {
337         Aml *crs;
338 
339         aml_append(cpu_ctrl_dev,
340             aml_name_decl("_HID", aml_eisaid("PNP0A06")));
341         aml_append(cpu_ctrl_dev,
342             aml_name_decl("_UID", aml_string("CPU Hotplug resources")));
343         aml_append(cpu_ctrl_dev, aml_mutex(CPU_LOCK, 0));
344 
345         crs = aml_resource_template();
346         aml_append(crs, aml_io(AML_DECODE16, io_base, io_base, 1,
347                                ACPI_CPU_HOTPLUG_REG_LEN));
348         aml_append(cpu_ctrl_dev, aml_name_decl("_CRS", crs));
349 
350         /* declare CPU hotplug MMIO region with related access fields */
351         aml_append(cpu_ctrl_dev,
352             aml_operation_region("PRST", AML_SYSTEM_IO, aml_int(io_base),
353                                  ACPI_CPU_HOTPLUG_REG_LEN));
354 
355         field = aml_field("PRST", AML_BYTE_ACC, AML_NOLOCK,
356                           AML_WRITE_AS_ZEROS);
357         aml_append(field, aml_reserved_field(ACPI_CPU_FLAGS_OFFSET_RW * 8));
358         /* 1 if enabled, read only */
359         aml_append(field, aml_named_field(CPU_ENABLED, 1));
360         /* (read) 1 if has a insert event. (write) 1 to clear event */
361         aml_append(field, aml_named_field(CPU_INSERT_EVENT, 1));
362         /* (read) 1 if has a remove event. (write) 1 to clear event */
363         aml_append(field, aml_named_field(CPU_REMOVE_EVENT, 1));
364         /* initiates device eject, write only */
365         aml_append(field, aml_named_field(CPU_EJECT_EVENT, 1));
366         aml_append(field, aml_reserved_field(4));
367         aml_append(field, aml_named_field(CPU_COMMAND, 8));
368         aml_append(cpu_ctrl_dev, field);
369 
370         field = aml_field("PRST", AML_DWORD_ACC, AML_NOLOCK, AML_PRESERVE);
371         /* CPU selector, write only */
372         aml_append(field, aml_named_field(CPU_SELECTOR, 32));
373         /* flags + cmd + 2byte align */
374         aml_append(field, aml_reserved_field(4 * 8));
375         aml_append(field, aml_named_field(CPU_DATA, 32));
376         aml_append(cpu_ctrl_dev, field);
377 
378         if (opts.has_legacy_cphp) {
379             method = aml_method("_INI", 0, AML_SERIALIZED);
380             /* switch off legacy CPU hotplug HW and use new one,
381              * on reboot system is in new mode and writing 0
382              * in CPU_SELECTOR selects BSP, which is NOP at
383              * the time _INI is called */
384             aml_append(method, aml_store(zero, aml_name(CPU_SELECTOR)));
385             aml_append(cpu_ctrl_dev, method);
386         }
387     }
388     aml_append(sb_scope, cpu_ctrl_dev);
389 
390     cpus_dev = aml_device("\\_SB.CPUS");
391     {
392         int i;
393         Aml *ctrl_lock = aml_name("%s.%s", cphp_res_path, CPU_LOCK);
394         Aml *cpu_selector = aml_name("%s.%s", cphp_res_path, CPU_SELECTOR);
395         Aml *is_enabled = aml_name("%s.%s", cphp_res_path, CPU_ENABLED);
396         Aml *cpu_cmd = aml_name("%s.%s", cphp_res_path, CPU_COMMAND);
397         Aml *cpu_data = aml_name("%s.%s", cphp_res_path, CPU_DATA);
398         Aml *ins_evt = aml_name("%s.%s", cphp_res_path, CPU_INSERT_EVENT);
399         Aml *rm_evt = aml_name("%s.%s", cphp_res_path, CPU_REMOVE_EVENT);
400         Aml *ej_evt = aml_name("%s.%s", cphp_res_path, CPU_EJECT_EVENT);
401 
402         aml_append(cpus_dev, aml_name_decl("_HID", aml_string("ACPI0010")));
403         aml_append(cpus_dev, aml_name_decl("_CID", aml_eisaid("PNP0A05")));
404 
405         method = aml_method(CPU_NOTIFY_METHOD, 2, AML_NOTSERIALIZED);
406         for (i = 0; i < arch_ids->len; i++) {
407             Aml *cpu = aml_name(CPU_NAME_FMT, i);
408             Aml *uid = aml_arg(0);
409             Aml *event = aml_arg(1);
410 
411             ifctx = aml_if(aml_equal(uid, aml_int(i)));
412             {
413                 aml_append(ifctx, aml_notify(cpu, event));
414             }
415             aml_append(method, ifctx);
416         }
417         aml_append(cpus_dev, method);
418 
419         method = aml_method(CPU_STS_METHOD, 1, AML_SERIALIZED);
420         {
421             Aml *idx = aml_arg(0);
422             Aml *sta = aml_local(0);
423 
424             aml_append(method, aml_acquire(ctrl_lock, 0xFFFF));
425             aml_append(method, aml_store(idx, cpu_selector));
426             aml_append(method, aml_store(zero, sta));
427             ifctx = aml_if(aml_equal(is_enabled, one));
428             {
429                 aml_append(ifctx, aml_store(aml_int(0xF), sta));
430             }
431             aml_append(method, ifctx);
432             aml_append(method, aml_release(ctrl_lock));
433             aml_append(method, aml_return(sta));
434         }
435         aml_append(cpus_dev, method);
436 
437         method = aml_method(CPU_EJECT_METHOD, 1, AML_SERIALIZED);
438         {
439             Aml *idx = aml_arg(0);
440 
441             aml_append(method, aml_acquire(ctrl_lock, 0xFFFF));
442             aml_append(method, aml_store(idx, cpu_selector));
443             aml_append(method, aml_store(one, ej_evt));
444             aml_append(method, aml_release(ctrl_lock));
445         }
446         aml_append(cpus_dev, method);
447 
448         method = aml_method(CPU_SCAN_METHOD, 0, AML_SERIALIZED);
449         {
450             Aml *else_ctx;
451             Aml *while_ctx;
452             Aml *has_event = aml_local(0);
453             Aml *dev_chk = aml_int(1);
454             Aml *eject_req = aml_int(3);
455             Aml *next_cpu_cmd = aml_int(CPHP_GET_NEXT_CPU_WITH_EVENT_CMD);
456 
457             aml_append(method, aml_acquire(ctrl_lock, 0xFFFF));
458             aml_append(method, aml_store(one, has_event));
459             while_ctx = aml_while(aml_equal(has_event, one));
460             {
461                  /* clear loop exit condition, ins_evt/rm_evt checks
462                   * will set it to 1 while next_cpu_cmd returns a CPU
463                   * with events */
464                  aml_append(while_ctx, aml_store(zero, has_event));
465                  aml_append(while_ctx, aml_store(next_cpu_cmd, cpu_cmd));
466                  ifctx = aml_if(aml_equal(ins_evt, one));
467                  {
468                      aml_append(ifctx,
469                          aml_call2(CPU_NOTIFY_METHOD, cpu_data, dev_chk));
470                      aml_append(ifctx, aml_store(one, ins_evt));
471                      aml_append(ifctx, aml_store(one, has_event));
472                  }
473                  aml_append(while_ctx, ifctx);
474                  else_ctx = aml_else();
475                  ifctx = aml_if(aml_equal(rm_evt, one));
476                  {
477                      aml_append(ifctx,
478                          aml_call2(CPU_NOTIFY_METHOD, cpu_data, eject_req));
479                      aml_append(ifctx, aml_store(one, rm_evt));
480                      aml_append(ifctx, aml_store(one, has_event));
481                  }
482                  aml_append(else_ctx, ifctx);
483                  aml_append(while_ctx, else_ctx);
484             }
485             aml_append(method, while_ctx);
486             aml_append(method, aml_release(ctrl_lock));
487         }
488         aml_append(cpus_dev, method);
489 
490         method = aml_method(CPU_OST_METHOD, 4, AML_SERIALIZED);
491         {
492             Aml *uid = aml_arg(0);
493             Aml *ev_cmd = aml_int(CPHP_OST_EVENT_CMD);
494             Aml *st_cmd = aml_int(CPHP_OST_STATUS_CMD);
495 
496             aml_append(method, aml_acquire(ctrl_lock, 0xFFFF));
497             aml_append(method, aml_store(uid, cpu_selector));
498             aml_append(method, aml_store(ev_cmd, cpu_cmd));
499             aml_append(method, aml_store(aml_arg(1), cpu_data));
500             aml_append(method, aml_store(st_cmd, cpu_cmd));
501             aml_append(method, aml_store(aml_arg(2), cpu_data));
502             aml_append(method, aml_release(ctrl_lock));
503         }
504         aml_append(cpus_dev, method);
505 
506         /* build Processor object for each processor */
507         for (i = 0; i < arch_ids->len; i++) {
508             Aml *dev;
509             Aml *uid = aml_int(i);
510             GArray *madt_buf = g_array_new(0, 1, 1);
511             int arch_id = arch_ids->cpus[i].arch_id;
512 
513             if (opts.acpi_1_compatible && arch_id < 255) {
514                 dev = aml_processor(i, 0, 0, CPU_NAME_FMT, i);
515             } else {
516                 dev = aml_device(CPU_NAME_FMT, i);
517                 aml_append(dev, aml_name_decl("_HID", aml_string("ACPI0007")));
518                 aml_append(dev, aml_name_decl("_UID", uid));
519             }
520 
521             method = aml_method("_STA", 0, AML_SERIALIZED);
522             aml_append(method, aml_return(aml_call1(CPU_STS_METHOD, uid)));
523             aml_append(dev, method);
524 
525             /* build _MAT object */
526             assert(adevc && adevc->madt_cpu);
527             adevc->madt_cpu(adev, i, arch_ids, madt_buf);
528             switch (madt_buf->data[0]) {
529             case ACPI_APIC_PROCESSOR: {
530                 AcpiMadtProcessorApic *apic = (void *)madt_buf->data;
531                 apic->flags = cpu_to_le32(1);
532                 break;
533             }
534             case ACPI_APIC_LOCAL_X2APIC: {
535                 AcpiMadtProcessorX2Apic *apic = (void *)madt_buf->data;
536                 apic->flags = cpu_to_le32(1);
537                 break;
538             }
539             default:
540                 assert(0);
541             }
542             aml_append(dev, aml_name_decl("_MAT",
543                 aml_buffer(madt_buf->len, (uint8_t *)madt_buf->data)));
544             g_array_free(madt_buf, true);
545 
546             if (CPU(arch_ids->cpus[i].cpu) != first_cpu) {
547                 method = aml_method("_EJ0", 1, AML_NOTSERIALIZED);
548                 aml_append(method, aml_call1(CPU_EJECT_METHOD, uid));
549                 aml_append(dev, method);
550             }
551 
552             method = aml_method("_OST", 3, AML_SERIALIZED);
553             aml_append(method,
554                 aml_call4(CPU_OST_METHOD, uid, aml_arg(0),
555                           aml_arg(1), aml_arg(2))
556             );
557             aml_append(dev, method);
558 
559             /* Linux guests discard SRAT info for non-present CPUs
560              * as a result _PXM is required for all CPUs which might
561              * be hot-plugged. For simplicity, add it for all CPUs.
562              */
563             if (arch_ids->cpus[i].props.has_node_id) {
564                 aml_append(dev, aml_name_decl("_PXM",
565                            aml_int(arch_ids->cpus[i].props.node_id)));
566             }
567 
568             aml_append(cpus_dev, dev);
569         }
570     }
571     aml_append(sb_scope, cpus_dev);
572     aml_append(table, sb_scope);
573 
574     method = aml_method(event_handler_method, 0, AML_NOTSERIALIZED);
575     aml_append(method, aml_call0("\\_SB.CPUS." CPU_SCAN_METHOD));
576     aml_append(table, method);
577 
578     g_free(cphp_res_path);
579 }
580