xref: /openbmc/qemu/hw/acpi/cpu.c (revision 88dd060d)
1 #include "qemu/osdep.h"
2 #include "migration/vmstate.h"
3 #include "hw/acpi/cpu.h"
4 #include "hw/core/cpu.h"
5 #include "qapi/error.h"
6 #include "qapi/qapi-events-acpi.h"
7 #include "trace.h"
8 #include "sysemu/numa.h"
9 
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 bool check_cpu_enabled_status(DeviceState *dev)
54 {
55     CPUClass *k = dev ? CPU_GET_CLASS(dev) : NULL;
56     CPUState *cpu = CPU(dev);
57 
58     if (cpu && (!k->cpu_enabled_status || k->cpu_enabled_status(cpu))) {
59         return true;
60     }
61 
62     return false;
63 }
64 
65 static uint64_t cpu_hotplug_rd(void *opaque, hwaddr addr, unsigned size)
66 {
67     uint64_t val = 0;
68     CPUHotplugState *cpu_st = opaque;
69     AcpiCpuStatus *cdev;
70 
71     if (cpu_st->selector >= cpu_st->dev_count) {
72         return val;
73     }
74 
75     cdev = &cpu_st->devs[cpu_st->selector];
76     switch (addr) {
77     case ACPI_CPU_FLAGS_OFFSET_RW: /* pack and return is_* fields */
78         val |= check_cpu_enabled_status(DEVICE(cdev->cpu)) ? 1 : 0;
79         val |= cdev->is_inserting ? 2 : 0;
80         val |= cdev->is_removing  ? 4 : 0;
81         val |= cdev->fw_remove  ? 16 : 0;
82         val |= cdev->cpu ? 32 : 0;
83         trace_cpuhp_acpi_read_flags(cpu_st->selector, val);
84         break;
85     case ACPI_CPU_CMD_DATA_OFFSET_RW:
86         switch (cpu_st->command) {
87         case CPHP_GET_NEXT_CPU_WITH_EVENT_CMD:
88            val = cpu_st->selector;
89            break;
90         case CPHP_GET_CPU_ID_CMD:
91            val = cdev->arch_id & 0xFFFFFFFF;
92            break;
93         default:
94            break;
95         }
96         trace_cpuhp_acpi_read_cmd_data(cpu_st->selector, val);
97         break;
98     case ACPI_CPU_CMD_DATA2_OFFSET_R:
99         switch (cpu_st->command) {
100         case CPHP_GET_NEXT_CPU_WITH_EVENT_CMD:
101            val = 0;
102            break;
103         case CPHP_GET_CPU_ID_CMD:
104            val = cdev->arch_id >> 32;
105            break;
106         default:
107            break;
108         }
109         trace_cpuhp_acpi_read_cmd_data2(cpu_st->selector, val);
110         break;
111     default:
112         break;
113     }
114     return val;
115 }
116 
117 static void cpu_hotplug_wr(void *opaque, hwaddr addr, uint64_t data,
118                            unsigned int size)
119 {
120     CPUHotplugState *cpu_st = opaque;
121     AcpiCpuStatus *cdev;
122     ACPIOSTInfo *info;
123 
124     assert(cpu_st->dev_count);
125 
126     if (addr) {
127         if (cpu_st->selector >= cpu_st->dev_count) {
128             trace_cpuhp_acpi_invalid_idx_selected(cpu_st->selector);
129             return;
130         }
131     }
132 
133     switch (addr) {
134     case ACPI_CPU_SELECTOR_OFFSET_WR: /* current CPU selector */
135         cpu_st->selector = data;
136         trace_cpuhp_acpi_write_idx(cpu_st->selector);
137         break;
138     case ACPI_CPU_FLAGS_OFFSET_RW: /* set is_* fields  */
139         cdev = &cpu_st->devs[cpu_st->selector];
140         if (data & 2) { /* clear insert event */
141             cdev->is_inserting = false;
142             trace_cpuhp_acpi_clear_inserting_evt(cpu_st->selector);
143         } else if (data & 4) { /* clear remove event */
144             cdev->is_removing = false;
145             trace_cpuhp_acpi_clear_remove_evt(cpu_st->selector);
146         } else if (data & 8) {
147             DeviceState *dev = NULL;
148             HotplugHandler *hotplug_ctrl = NULL;
149 
150             if (!cdev->cpu || cdev->cpu == first_cpu) {
151                 trace_cpuhp_acpi_ejecting_invalid_cpu(cpu_st->selector);
152                 break;
153             }
154 
155             trace_cpuhp_acpi_ejecting_cpu(cpu_st->selector);
156             dev = DEVICE(cdev->cpu);
157             hotplug_ctrl = qdev_get_hotplug_handler(dev);
158             hotplug_handler_unplug(hotplug_ctrl, dev, NULL);
159             object_unparent(OBJECT(dev));
160             cdev->fw_remove = false;
161         } else if (data & 16) {
162             if (!cdev->cpu || cdev->cpu == first_cpu) {
163                 trace_cpuhp_acpi_fw_remove_invalid_cpu(cpu_st->selector);
164                 break;
165             }
166             trace_cpuhp_acpi_fw_remove_cpu(cpu_st->selector);
167             cdev->fw_remove = true;
168         }
169         break;
170     case ACPI_CPU_CMD_OFFSET_WR:
171         trace_cpuhp_acpi_write_cmd(cpu_st->selector, data);
172         if (data < CPHP_CMD_MAX) {
173             cpu_st->command = data;
174             if (cpu_st->command == CPHP_GET_NEXT_CPU_WITH_EVENT_CMD) {
175                 uint32_t iter = cpu_st->selector;
176 
177                 do {
178                     cdev = &cpu_st->devs[iter];
179                     if (cdev->is_inserting || cdev->is_removing ||
180                         cdev->fw_remove) {
181                         cpu_st->selector = iter;
182                         trace_cpuhp_acpi_cpu_has_events(cpu_st->selector,
183                             cdev->is_inserting, cdev->is_removing);
184                         break;
185                     }
186                     iter = iter + 1 < cpu_st->dev_count ? iter + 1 : 0;
187                 } while (iter != cpu_st->selector);
188             }
189         }
190         break;
191     case ACPI_CPU_CMD_DATA_OFFSET_RW:
192         switch (cpu_st->command) {
193         case CPHP_OST_EVENT_CMD: {
194            cdev = &cpu_st->devs[cpu_st->selector];
195            cdev->ost_event = data;
196            trace_cpuhp_acpi_write_ost_ev(cpu_st->selector, cdev->ost_event);
197            break;
198         }
199         case CPHP_OST_STATUS_CMD: {
200            cdev = &cpu_st->devs[cpu_st->selector];
201            cdev->ost_status = data;
202            info = acpi_cpu_device_status(cpu_st->selector, cdev);
203            qapi_event_send_acpi_device_ost(info);
204            qapi_free_ACPIOSTInfo(info);
205            trace_cpuhp_acpi_write_ost_status(cpu_st->selector,
206                                              cdev->ost_status);
207            break;
208         }
209         default:
210            break;
211         }
212         break;
213     default:
214         break;
215     }
216 }
217 
218 static const MemoryRegionOps cpu_hotplug_ops = {
219     .read = cpu_hotplug_rd,
220     .write = cpu_hotplug_wr,
221     .endianness = DEVICE_LITTLE_ENDIAN,
222     .valid = {
223         .min_access_size = 1,
224         .max_access_size = 4,
225     },
226 };
227 
228 void cpu_hotplug_hw_init(MemoryRegion *as, Object *owner,
229                          CPUHotplugState *state, hwaddr base_addr)
230 {
231     MachineState *machine = MACHINE(qdev_get_machine());
232     MachineClass *mc = MACHINE_GET_CLASS(machine);
233     const CPUArchIdList *id_list;
234     int i;
235 
236     assert(mc->possible_cpu_arch_ids);
237     id_list = mc->possible_cpu_arch_ids(machine);
238     state->dev_count = id_list->len;
239     state->devs = g_new0(typeof(*state->devs), state->dev_count);
240     for (i = 0; i < id_list->len; i++) {
241         state->devs[i].cpu =  CPU(id_list->cpus[i].cpu);
242         state->devs[i].arch_id = id_list->cpus[i].arch_id;
243     }
244     memory_region_init_io(&state->ctrl_reg, owner, &cpu_hotplug_ops, state,
245                           "acpi-cpu-hotplug", ACPI_CPU_HOTPLUG_REG_LEN);
246     memory_region_add_subregion(as, base_addr, &state->ctrl_reg);
247 }
248 
249 static bool should_remain_acpi_present(DeviceState *dev)
250 {
251     CPUClass *k = CPU_GET_CLASS(dev);
252     /*
253      * A system may contain CPUs that are always present on one die, NUMA node,
254      * or socket, yet may be non-present on another simultaneously. Check from
255      * architecture specific code.
256      */
257     return k->cpu_persistent_status && k->cpu_persistent_status(CPU(dev));
258 }
259 
260 static AcpiCpuStatus *get_cpu_status(CPUHotplugState *cpu_st, DeviceState *dev)
261 {
262     CPUClass *k = CPU_GET_CLASS(dev);
263     uint64_t cpu_arch_id = k->get_arch_id(CPU(dev));
264     int i;
265 
266     for (i = 0; i < cpu_st->dev_count; i++) {
267         if (cpu_arch_id == cpu_st->devs[i].arch_id) {
268             return &cpu_st->devs[i];
269         }
270     }
271     return NULL;
272 }
273 
274 void acpi_cpu_plug_cb(HotplugHandler *hotplug_dev,
275                       CPUHotplugState *cpu_st, DeviceState *dev, Error **errp)
276 {
277     AcpiCpuStatus *cdev;
278 
279     cdev = get_cpu_status(cpu_st, dev);
280     if (!cdev) {
281         return;
282     }
283 
284     cdev->cpu = CPU(dev);
285     if (dev->hotplugged) {
286         cdev->is_inserting = true;
287         acpi_send_event(DEVICE(hotplug_dev), ACPI_CPU_HOTPLUG_STATUS);
288     }
289 }
290 
291 void acpi_cpu_unplug_request_cb(HotplugHandler *hotplug_dev,
292                                 CPUHotplugState *cpu_st,
293                                 DeviceState *dev, Error **errp)
294 {
295     AcpiCpuStatus *cdev;
296 
297     cdev = get_cpu_status(cpu_st, dev);
298     if (!cdev) {
299         return;
300     }
301 
302     cdev->is_removing = true;
303     acpi_send_event(DEVICE(hotplug_dev), ACPI_CPU_HOTPLUG_STATUS);
304 }
305 
306 void acpi_cpu_unplug_cb(CPUHotplugState *cpu_st,
307                         DeviceState *dev, Error **errp)
308 {
309     AcpiCpuStatus *cdev;
310 
311     cdev = get_cpu_status(cpu_st, dev);
312     if (!cdev) {
313         return;
314     }
315 
316     if (!should_remain_acpi_present(dev)) {
317         cdev->cpu = NULL;
318     }
319 }
320 
321 static const VMStateDescription vmstate_cpuhp_sts = {
322     .name = "CPU hotplug device state",
323     .version_id = 1,
324     .minimum_version_id = 1,
325     .fields = (const VMStateField[]) {
326         VMSTATE_BOOL(is_inserting, AcpiCpuStatus),
327         VMSTATE_BOOL(is_removing, AcpiCpuStatus),
328         VMSTATE_UINT32(ost_event, AcpiCpuStatus),
329         VMSTATE_UINT32(ost_status, AcpiCpuStatus),
330         VMSTATE_END_OF_LIST()
331     }
332 };
333 
334 const VMStateDescription vmstate_cpu_hotplug = {
335     .name = "CPU hotplug state",
336     .version_id = 1,
337     .minimum_version_id = 1,
338     .fields = (const VMStateField[]) {
339         VMSTATE_UINT32(selector, CPUHotplugState),
340         VMSTATE_UINT8(command, CPUHotplugState),
341         VMSTATE_STRUCT_VARRAY_POINTER_UINT32(devs, CPUHotplugState, dev_count,
342                                              vmstate_cpuhp_sts, AcpiCpuStatus),
343         VMSTATE_END_OF_LIST()
344     }
345 };
346 
347 #define CPU_NAME_FMT      "C%.03X"
348 #define CPUHP_RES_DEVICE  "PRES"
349 #define CPU_LOCK          "CPLK"
350 #define CPU_STS_METHOD    "CSTA"
351 #define CPU_SCAN_METHOD   "CSCN"
352 #define CPU_NOTIFY_METHOD "CTFY"
353 #define CPU_EJECT_METHOD  "CEJ0"
354 #define CPU_OST_METHOD    "COST"
355 #define CPU_ADDED_LIST    "CNEW"
356 
357 #define CPU_ENABLED       "CPEN"
358 #define CPU_SELECTOR      "CSEL"
359 #define CPU_COMMAND       "CCMD"
360 #define CPU_DATA          "CDAT"
361 #define CPU_INSERT_EVENT  "CINS"
362 #define CPU_REMOVE_EVENT  "CRMV"
363 #define CPU_EJECT_EVENT   "CEJ0"
364 #define CPU_FW_EJECT_EVENT "CEJF"
365 #define CPU_PRESENT       "CPRS"
366 
367 void build_cpus_aml(Aml *table, MachineState *machine, CPUHotplugFeatures opts,
368                     build_madt_cpu_fn build_madt_cpu, hwaddr base_addr,
369                     const char *res_root,
370                     const char *event_handler_method,
371                     AmlRegionSpace rs)
372 {
373     Aml *ifctx;
374     Aml *field;
375     Aml *method;
376     Aml *cpu_ctrl_dev;
377     Aml *cpus_dev;
378     Aml *zero = aml_int(0);
379     Aml *one = aml_int(1);
380     Aml *sb_scope = aml_scope("_SB");
381     MachineClass *mc = MACHINE_GET_CLASS(machine);
382     const CPUArchIdList *arch_ids = mc->possible_cpu_arch_ids(machine);
383     char *cphp_res_path = g_strdup_printf("%s." CPUHP_RES_DEVICE, res_root);
384 
385     cpu_ctrl_dev = aml_device("%s", cphp_res_path);
386     {
387         Aml *crs;
388 
389         aml_append(cpu_ctrl_dev,
390             aml_name_decl("_HID", aml_eisaid("PNP0A06")));
391         aml_append(cpu_ctrl_dev,
392             aml_name_decl("_UID", aml_string("CPU Hotplug resources")));
393         aml_append(cpu_ctrl_dev, aml_mutex(CPU_LOCK, 0));
394 
395         assert((rs == AML_SYSTEM_IO) || (rs == AML_SYSTEM_MEMORY));
396 
397         crs = aml_resource_template();
398         if (rs == AML_SYSTEM_IO) {
399             aml_append(crs, aml_io(AML_DECODE16, base_addr, base_addr, 1,
400                                ACPI_CPU_HOTPLUG_REG_LEN));
401         } else if (rs == AML_SYSTEM_MEMORY) {
402             aml_append(crs, aml_memory32_fixed(base_addr,
403                                ACPI_CPU_HOTPLUG_REG_LEN, AML_READ_WRITE));
404         }
405 
406         aml_append(cpu_ctrl_dev, aml_name_decl("_CRS", crs));
407 
408         /* declare CPU hotplug MMIO region with related access fields */
409         aml_append(cpu_ctrl_dev,
410             aml_operation_region("PRST", rs, aml_int(base_addr),
411                                  ACPI_CPU_HOTPLUG_REG_LEN));
412 
413         field = aml_field("PRST", AML_BYTE_ACC, AML_NOLOCK,
414                           AML_WRITE_AS_ZEROS);
415         aml_append(field, aml_reserved_field(ACPI_CPU_FLAGS_OFFSET_RW * 8));
416         /* 1 if enabled, read only */
417         aml_append(field, aml_named_field(CPU_ENABLED, 1));
418         /* (read) 1 if has a insert event. (write) 1 to clear event */
419         aml_append(field, aml_named_field(CPU_INSERT_EVENT, 1));
420         /* (read) 1 if has a remove event. (write) 1 to clear event */
421         aml_append(field, aml_named_field(CPU_REMOVE_EVENT, 1));
422         /* initiates device eject, write only */
423         aml_append(field, aml_named_field(CPU_EJECT_EVENT, 1));
424         /* tell firmware to do device eject, write only */
425         aml_append(field, aml_named_field(CPU_FW_EJECT_EVENT, 1));
426         /* 1 if present, read only */
427         aml_append(field, aml_named_field(CPU_PRESENT, 1));
428         aml_append(field, aml_reserved_field(2));
429         aml_append(field, aml_named_field(CPU_COMMAND, 8));
430         aml_append(cpu_ctrl_dev, field);
431 
432         field = aml_field("PRST", AML_DWORD_ACC, AML_NOLOCK, AML_PRESERVE);
433         /* CPU selector, write only */
434         aml_append(field, aml_named_field(CPU_SELECTOR, 32));
435         /* flags + cmd + 2byte align */
436         aml_append(field, aml_reserved_field(4 * 8));
437         aml_append(field, aml_named_field(CPU_DATA, 32));
438         aml_append(cpu_ctrl_dev, field);
439 
440         if (opts.has_legacy_cphp) {
441             method = aml_method("_INI", 0, AML_SERIALIZED);
442             /* switch off legacy CPU hotplug HW and use new one,
443              * on reboot system is in new mode and writing 0
444              * in CPU_SELECTOR selects BSP, which is NOP at
445              * the time _INI is called */
446             aml_append(method, aml_store(zero, aml_name(CPU_SELECTOR)));
447             aml_append(cpu_ctrl_dev, method);
448         }
449     }
450     aml_append(sb_scope, cpu_ctrl_dev);
451 
452     cpus_dev = aml_device("\\_SB.CPUS");
453     {
454         int i;
455         Aml *ctrl_lock = aml_name("%s.%s", cphp_res_path, CPU_LOCK);
456         Aml *cpu_selector = aml_name("%s.%s", cphp_res_path, CPU_SELECTOR);
457         Aml *is_enabled = aml_name("%s.%s", cphp_res_path, CPU_ENABLED);
458         Aml *is_present = aml_name("%s.%s", cphp_res_path, CPU_PRESENT);
459         Aml *cpu_cmd = aml_name("%s.%s", cphp_res_path, CPU_COMMAND);
460         Aml *cpu_data = aml_name("%s.%s", cphp_res_path, CPU_DATA);
461         Aml *ins_evt = aml_name("%s.%s", cphp_res_path, CPU_INSERT_EVENT);
462         Aml *rm_evt = aml_name("%s.%s", cphp_res_path, CPU_REMOVE_EVENT);
463         Aml *ej_evt = aml_name("%s.%s", cphp_res_path, CPU_EJECT_EVENT);
464         Aml *fw_ej_evt = aml_name("%s.%s", cphp_res_path, CPU_FW_EJECT_EVENT);
465 
466         aml_append(cpus_dev, aml_name_decl("_HID", aml_string("ACPI0010")));
467         aml_append(cpus_dev, aml_name_decl("_CID", aml_eisaid("PNP0A05")));
468 
469         method = aml_method(CPU_NOTIFY_METHOD, 2, AML_NOTSERIALIZED);
470         for (i = 0; i < arch_ids->len; i++) {
471             Aml *cpu = aml_name(CPU_NAME_FMT, i);
472             Aml *uid = aml_arg(0);
473             Aml *event = aml_arg(1);
474 
475             ifctx = aml_if(aml_equal(uid, aml_int(i)));
476             {
477                 aml_append(ifctx, aml_notify(cpu, event));
478             }
479             aml_append(method, ifctx);
480         }
481         aml_append(cpus_dev, method);
482 
483         method = aml_method(CPU_STS_METHOD, 1, AML_SERIALIZED);
484         {
485             Aml *idx = aml_arg(0);
486             Aml *sta = aml_local(0);
487             Aml *ifctx2;
488             Aml *else_ctx;
489 
490             aml_append(method, aml_acquire(ctrl_lock, 0xFFFF));
491             aml_append(method, aml_store(idx, cpu_selector));
492             aml_append(method, aml_store(zero, sta));
493             ifctx = aml_if(aml_equal(is_present, one));
494             {
495                 ifctx2 = aml_if(aml_equal(is_enabled, one));
496                 {
497                     /* cpu is present and enabled */
498                     aml_append(ifctx2, aml_store(aml_int(0xF), sta));
499                 }
500                 aml_append(ifctx, ifctx2);
501                 else_ctx = aml_else();
502                 {
503                     /* cpu is present but disabled */
504                     aml_append(else_ctx, aml_store(aml_int(0xD), sta));
505                 }
506                 aml_append(ifctx, else_ctx);
507             }
508             aml_append(method, ifctx);
509             aml_append(method, aml_release(ctrl_lock));
510             aml_append(method, aml_return(sta));
511         }
512         aml_append(cpus_dev, method);
513 
514         method = aml_method(CPU_EJECT_METHOD, 1, AML_SERIALIZED);
515         {
516             Aml *idx = aml_arg(0);
517 
518             aml_append(method, aml_acquire(ctrl_lock, 0xFFFF));
519             aml_append(method, aml_store(idx, cpu_selector));
520             if (opts.fw_unplugs_cpu) {
521                 aml_append(method, aml_store(one, fw_ej_evt));
522                 aml_append(method, aml_store(aml_int(OVMF_CPUHP_SMI_CMD),
523                            aml_name("%s", opts.smi_path)));
524             } else {
525                 aml_append(method, aml_store(one, ej_evt));
526             }
527             aml_append(method, aml_release(ctrl_lock));
528         }
529         aml_append(cpus_dev, method);
530 
531         method = aml_method(CPU_SCAN_METHOD, 0, AML_SERIALIZED);
532         {
533             const uint8_t max_cpus_per_pass = 255;
534             Aml *else_ctx;
535             Aml *while_ctx, *while_ctx2;
536             Aml *has_event = aml_local(0);
537             Aml *dev_chk = aml_int(1);
538             Aml *eject_req = aml_int(3);
539             Aml *next_cpu_cmd = aml_int(CPHP_GET_NEXT_CPU_WITH_EVENT_CMD);
540             Aml *num_added_cpus = aml_local(1);
541             Aml *cpu_idx = aml_local(2);
542             Aml *uid = aml_local(3);
543             Aml *has_job = aml_local(4);
544             Aml *new_cpus = aml_name(CPU_ADDED_LIST);
545 
546             aml_append(method, aml_acquire(ctrl_lock, 0xFFFF));
547 
548             /*
549              * Windows versions newer than XP (including Windows 10/Windows
550              * Server 2019), do support* VarPackageOp but, it is cripled to hold
551              * the same elements number as old PackageOp.
552              * For compatibility with Windows XP (so it won't crash) use ACPI1.0
553              * PackageOp which can hold max 255 elements.
554              *
555              * use named package as old Windows don't support it in local var
556              */
557             aml_append(method, aml_name_decl(CPU_ADDED_LIST,
558                                              aml_package(max_cpus_per_pass)));
559 
560             aml_append(method, aml_store(zero, uid));
561             aml_append(method, aml_store(one, has_job));
562             /*
563              * CPU_ADDED_LIST can hold limited number of elements, outer loop
564              * allows to process CPUs in batches which let us to handle more
565              * CPUs than CPU_ADDED_LIST can hold.
566              */
567             while_ctx2 = aml_while(aml_equal(has_job, one));
568             {
569                 aml_append(while_ctx2, aml_store(zero, has_job));
570 
571                 aml_append(while_ctx2, aml_store(one, has_event));
572                 aml_append(while_ctx2, aml_store(zero, num_added_cpus));
573 
574                 /*
575                  * Scan CPUs, till there are CPUs with events or
576                  * CPU_ADDED_LIST capacity is exhausted
577                  */
578                 while_ctx = aml_while(aml_land(aml_equal(has_event, one),
579                                       aml_lless(uid, aml_int(arch_ids->len))));
580                 {
581                      /*
582                       * clear loop exit condition, ins_evt/rm_evt checks will
583                       * set it to 1 while next_cpu_cmd returns a CPU with events
584                       */
585                      aml_append(while_ctx, aml_store(zero, has_event));
586 
587                      aml_append(while_ctx, aml_store(uid, cpu_selector));
588                      aml_append(while_ctx, aml_store(next_cpu_cmd, cpu_cmd));
589 
590                      /*
591                       * wrap around case, scan is complete, exit loop.
592                       * It happens since events are not cleared in scan loop,
593                       * so next_cpu_cmd continues to find already processed CPUs
594                       */
595                      ifctx = aml_if(aml_lless(cpu_data, uid));
596                      {
597                          aml_append(ifctx, aml_break());
598                      }
599                      aml_append(while_ctx, ifctx);
600 
601                      /*
602                       * if CPU_ADDED_LIST is full, exit inner loop and process
603                       * collected CPUs
604                       */
605                      ifctx = aml_if(
606                          aml_equal(num_added_cpus, aml_int(max_cpus_per_pass)));
607                      {
608                          aml_append(ifctx, aml_store(one, has_job));
609                          aml_append(ifctx, aml_break());
610                      }
611                      aml_append(while_ctx, ifctx);
612 
613                      aml_append(while_ctx, aml_store(cpu_data, uid));
614                      ifctx = aml_if(aml_equal(ins_evt, one));
615                      {
616                          /* cache added CPUs to Notify/Wakeup later */
617                          aml_append(ifctx, aml_store(uid,
618                              aml_index(new_cpus, num_added_cpus)));
619                          aml_append(ifctx, aml_increment(num_added_cpus));
620                          aml_append(ifctx, aml_store(one, has_event));
621                      }
622                      aml_append(while_ctx, ifctx);
623                      else_ctx = aml_else();
624                      ifctx = aml_if(aml_equal(rm_evt, one));
625                      {
626                          aml_append(ifctx,
627                              aml_call2(CPU_NOTIFY_METHOD, uid, eject_req));
628                          aml_append(ifctx, aml_store(one, rm_evt));
629                          aml_append(ifctx, aml_store(one, has_event));
630                      }
631                      aml_append(else_ctx, ifctx);
632                      aml_append(while_ctx, else_ctx);
633                      aml_append(while_ctx, aml_increment(uid));
634                 }
635                 aml_append(while_ctx2, while_ctx);
636 
637                 /*
638                  * in case FW negotiated ICH9_LPC_SMI_F_CPU_HOTPLUG_BIT,
639                  * make upcall to FW, so it can pull in new CPUs before
640                  * OS is notified and wakes them up
641                  */
642                 if (opts.smi_path) {
643                     ifctx = aml_if(aml_lgreater(num_added_cpus, zero));
644                     {
645                         aml_append(ifctx, aml_store(aml_int(OVMF_CPUHP_SMI_CMD),
646                             aml_name("%s", opts.smi_path)));
647                     }
648                     aml_append(while_ctx2, ifctx);
649                 }
650 
651                 /* Notify OSPM about new CPUs and clear insert events */
652                 aml_append(while_ctx2, aml_store(zero, cpu_idx));
653                 while_ctx = aml_while(aml_lless(cpu_idx, num_added_cpus));
654                 {
655                     aml_append(while_ctx,
656                         aml_store(aml_derefof(aml_index(new_cpus, cpu_idx)),
657                                   uid));
658                     aml_append(while_ctx,
659                         aml_call2(CPU_NOTIFY_METHOD, uid, dev_chk));
660                     aml_append(while_ctx, aml_store(uid, aml_debug()));
661                     aml_append(while_ctx, aml_store(uid, cpu_selector));
662                     aml_append(while_ctx, aml_store(one, ins_evt));
663                     aml_append(while_ctx, aml_increment(cpu_idx));
664                 }
665                 aml_append(while_ctx2, while_ctx);
666                 /*
667                  * If another batch is needed, then it will resume scanning
668                  * exactly at -- and not after -- the last CPU that's currently
669                  * in CPU_ADDED_LIST. In other words, the last CPU in
670                  * CPU_ADDED_LIST is going to be re-checked. That's OK: we've
671                  * just cleared the insert event for *all* CPUs in
672                  * CPU_ADDED_LIST, including the last one. So the scan will
673                  * simply seek past it.
674                  */
675             }
676             aml_append(method, while_ctx2);
677             aml_append(method, aml_release(ctrl_lock));
678         }
679         aml_append(cpus_dev, method);
680 
681         method = aml_method(CPU_OST_METHOD, 4, AML_SERIALIZED);
682         {
683             Aml *uid = aml_arg(0);
684             Aml *ev_cmd = aml_int(CPHP_OST_EVENT_CMD);
685             Aml *st_cmd = aml_int(CPHP_OST_STATUS_CMD);
686 
687             aml_append(method, aml_acquire(ctrl_lock, 0xFFFF));
688             aml_append(method, aml_store(uid, cpu_selector));
689             aml_append(method, aml_store(ev_cmd, cpu_cmd));
690             aml_append(method, aml_store(aml_arg(1), cpu_data));
691             aml_append(method, aml_store(st_cmd, cpu_cmd));
692             aml_append(method, aml_store(aml_arg(2), cpu_data));
693             aml_append(method, aml_release(ctrl_lock));
694         }
695         aml_append(cpus_dev, method);
696 
697         /* build Processor object for each processor */
698         for (i = 0; i < arch_ids->len; i++) {
699             Aml *dev;
700             Aml *uid = aml_int(i);
701             GArray *madt_buf = g_array_new(0, 1, 1);
702             int arch_id = arch_ids->cpus[i].arch_id;
703 
704             if (opts.acpi_1_compatible && arch_id < 255) {
705                 dev = aml_processor(i, 0, 0, CPU_NAME_FMT, i);
706             } else {
707                 dev = aml_device(CPU_NAME_FMT, i);
708                 aml_append(dev, aml_name_decl("_HID", aml_string("ACPI0007")));
709                 aml_append(dev, aml_name_decl("_UID", uid));
710             }
711 
712             method = aml_method("_STA", 0, AML_SERIALIZED);
713             aml_append(method, aml_return(aml_call1(CPU_STS_METHOD, uid)));
714             aml_append(dev, method);
715 
716             /* build _MAT object */
717             build_madt_cpu(i, arch_ids, madt_buf, true); /* set enabled flag */
718             aml_append(dev, aml_name_decl("_MAT",
719                 aml_buffer(madt_buf->len, (uint8_t *)madt_buf->data)));
720             g_array_free(madt_buf, true);
721 
722             if (CPU(arch_ids->cpus[i].cpu) != first_cpu) {
723                 method = aml_method("_EJ0", 1, AML_NOTSERIALIZED);
724                 aml_append(method, aml_call1(CPU_EJECT_METHOD, uid));
725                 aml_append(dev, method);
726             }
727 
728             method = aml_method("_OST", 3, AML_SERIALIZED);
729             aml_append(method,
730                 aml_call4(CPU_OST_METHOD, uid, aml_arg(0),
731                           aml_arg(1), aml_arg(2))
732             );
733             aml_append(dev, method);
734 
735             /* Linux guests discard SRAT info for non-present CPUs
736              * as a result _PXM is required for all CPUs which might
737              * be hot-plugged. For simplicity, add it for all CPUs.
738              */
739             if (arch_ids->cpus[i].props.has_node_id) {
740                 aml_append(dev, aml_name_decl("_PXM",
741                            aml_int(arch_ids->cpus[i].props.node_id)));
742             }
743 
744             aml_append(cpus_dev, dev);
745         }
746     }
747     aml_append(sb_scope, cpus_dev);
748     aml_append(table, sb_scope);
749 
750     method = aml_method(event_handler_method, 0, AML_NOTSERIALIZED);
751     aml_append(method, aml_call0("\\_SB.CPUS." CPU_SCAN_METHOD));
752     aml_append(table, method);
753 
754     g_free(cphp_res_path);
755 }
756