xref: /openbmc/qemu/hw/acpi/piix4.c (revision b957a1b0)
1 /*
2  * ACPI implementation
3  *
4  * Copyright (c) 2006 Fabrice Bellard
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License version 2 as published by the Free Software Foundation.
9  *
10  * This library is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with this library; if not, see <http://www.gnu.org/licenses/>
17  *
18  * Contributions after 2012-01-13 are licensed under the terms of the
19  * GNU GPL, version 2 or (at your option) any later version.
20  */
21 #include "hw/hw.h"
22 #include "hw/i386/pc.h"
23 #include "hw/isa/apm.h"
24 #include "hw/i2c/pm_smbus.h"
25 #include "hw/pci/pci.h"
26 #include "hw/acpi/acpi.h"
27 #include "sysemu/sysemu.h"
28 #include "qemu/range.h"
29 #include "exec/ioport.h"
30 #include "hw/nvram/fw_cfg.h"
31 #include "exec/address-spaces.h"
32 
33 //#define DEBUG
34 
35 #ifdef DEBUG
36 # define PIIX4_DPRINTF(format, ...)     printf(format, ## __VA_ARGS__)
37 #else
38 # define PIIX4_DPRINTF(format, ...)     do { } while (0)
39 #endif
40 
41 #define GPE_BASE 0xafe0
42 #define GPE_LEN 4
43 
44 #define PCI_HOTPLUG_ADDR 0xae00
45 #define PCI_HOTPLUG_SIZE 0x000f
46 #define PCI_UP_BASE 0xae00
47 #define PCI_DOWN_BASE 0xae04
48 #define PCI_EJ_BASE 0xae08
49 #define PCI_RMV_BASE 0xae0c
50 
51 #define PIIX4_PROC_BASE 0xaf00
52 #define PIIX4_PROC_LEN 32
53 
54 #define PIIX4_PCI_HOTPLUG_STATUS 2
55 #define PIIX4_CPU_HOTPLUG_STATUS 4
56 
57 struct pci_status {
58     uint32_t up; /* deprecated, maintained for migration compatibility */
59     uint32_t down;
60 };
61 
62 typedef struct CPUStatus {
63     uint8_t sts[PIIX4_PROC_LEN];
64 } CPUStatus;
65 
66 typedef struct PIIX4PMState {
67     PCIDevice dev;
68 
69     MemoryRegion io;
70     MemoryRegion io_gpe;
71     MemoryRegion io_pci;
72     MemoryRegion io_cpu;
73     ACPIREGS ar;
74 
75     APMState apm;
76 
77     PMSMBus smb;
78     uint32_t smb_io_base;
79 
80     qemu_irq irq;
81     qemu_irq smi_irq;
82     int kvm_enabled;
83     Notifier machine_ready;
84     Notifier powerdown_notifier;
85 
86     /* for pci hotplug */
87     struct pci_status pci0_status;
88     uint32_t pci0_hotplug_enable;
89     uint32_t pci0_slot_device_present;
90 
91     uint8_t disable_s3;
92     uint8_t disable_s4;
93     uint8_t s4_val;
94 
95     CPUStatus gpe_cpu;
96     Notifier cpu_added_notifier;
97 } PIIX4PMState;
98 
99 static void piix4_acpi_system_hot_add_init(MemoryRegion *parent,
100                                            PCIBus *bus, PIIX4PMState *s);
101 
102 #define ACPI_ENABLE 0xf1
103 #define ACPI_DISABLE 0xf0
104 
105 static void pm_update_sci(PIIX4PMState *s)
106 {
107     int sci_level, pmsts;
108 
109     pmsts = acpi_pm1_evt_get_sts(&s->ar);
110     sci_level = (((pmsts & s->ar.pm1.evt.en) &
111                   (ACPI_BITMASK_RT_CLOCK_ENABLE |
112                    ACPI_BITMASK_POWER_BUTTON_ENABLE |
113                    ACPI_BITMASK_GLOBAL_LOCK_ENABLE |
114                    ACPI_BITMASK_TIMER_ENABLE)) != 0) ||
115         (((s->ar.gpe.sts[0] & s->ar.gpe.en[0]) &
116           (PIIX4_PCI_HOTPLUG_STATUS | PIIX4_CPU_HOTPLUG_STATUS)) != 0);
117 
118     qemu_set_irq(s->irq, sci_level);
119     /* schedule a timer interruption if needed */
120     acpi_pm_tmr_update(&s->ar, (s->ar.pm1.evt.en & ACPI_BITMASK_TIMER_ENABLE) &&
121                        !(pmsts & ACPI_BITMASK_TIMER_STATUS));
122 }
123 
124 static void pm_tmr_timer(ACPIREGS *ar)
125 {
126     PIIX4PMState *s = container_of(ar, PIIX4PMState, ar);
127     pm_update_sci(s);
128 }
129 
130 static void apm_ctrl_changed(uint32_t val, void *arg)
131 {
132     PIIX4PMState *s = arg;
133 
134     /* ACPI specs 3.0, 4.7.2.5 */
135     acpi_pm1_cnt_update(&s->ar, val == ACPI_ENABLE, val == ACPI_DISABLE);
136 
137     if (s->dev.config[0x5b] & (1 << 1)) {
138         if (s->smi_irq) {
139             qemu_irq_raise(s->smi_irq);
140         }
141     }
142 }
143 
144 static void pm_io_space_update(PIIX4PMState *s)
145 {
146     uint32_t pm_io_base;
147 
148     pm_io_base = le32_to_cpu(*(uint32_t *)(s->dev.config + 0x40));
149     pm_io_base &= 0xffc0;
150 
151     memory_region_transaction_begin();
152     memory_region_set_enabled(&s->io, s->dev.config[0x80] & 1);
153     memory_region_set_address(&s->io, pm_io_base);
154     memory_region_transaction_commit();
155 }
156 
157 static void smbus_io_space_update(PIIX4PMState *s)
158 {
159     s->smb_io_base = le32_to_cpu(*(uint32_t *)(s->dev.config + 0x90));
160     s->smb_io_base &= 0xffc0;
161 
162     memory_region_transaction_begin();
163     memory_region_set_enabled(&s->smb.io, s->dev.config[0xd2] & 1);
164     memory_region_set_address(&s->smb.io, s->smb_io_base);
165     memory_region_transaction_commit();
166 }
167 
168 static void pm_write_config(PCIDevice *d,
169                             uint32_t address, uint32_t val, int len)
170 {
171     pci_default_write_config(d, address, val, len);
172     if (range_covers_byte(address, len, 0x80) ||
173         ranges_overlap(address, len, 0x40, 4)) {
174         pm_io_space_update((PIIX4PMState *)d);
175     }
176     if (range_covers_byte(address, len, 0xd2) ||
177         ranges_overlap(address, len, 0x90, 4)) {
178         smbus_io_space_update((PIIX4PMState *)d);
179     }
180 }
181 
182 static void vmstate_pci_status_pre_save(void *opaque)
183 {
184     struct pci_status *pci0_status = opaque;
185     PIIX4PMState *s = container_of(pci0_status, PIIX4PMState, pci0_status);
186 
187     /* We no longer track up, so build a safe value for migrating
188      * to a version that still does... of course these might get lost
189      * by an old buggy implementation, but we try. */
190     pci0_status->up = s->pci0_slot_device_present & s->pci0_hotplug_enable;
191 }
192 
193 static int vmstate_acpi_post_load(void *opaque, int version_id)
194 {
195     PIIX4PMState *s = opaque;
196 
197     pm_io_space_update(s);
198     return 0;
199 }
200 
201 #define VMSTATE_GPE_ARRAY(_field, _state)                            \
202  {                                                                   \
203      .name       = (stringify(_field)),                              \
204      .version_id = 0,                                                \
205      .info       = &vmstate_info_uint16,                             \
206      .size       = sizeof(uint16_t),                                 \
207      .flags      = VMS_SINGLE | VMS_POINTER,                         \
208      .offset     = vmstate_offset_pointer(_state, _field, uint8_t),  \
209  }
210 
211 static const VMStateDescription vmstate_gpe = {
212     .name = "gpe",
213     .version_id = 1,
214     .minimum_version_id = 1,
215     .minimum_version_id_old = 1,
216     .fields      = (VMStateField []) {
217         VMSTATE_GPE_ARRAY(sts, ACPIGPE),
218         VMSTATE_GPE_ARRAY(en, ACPIGPE),
219         VMSTATE_END_OF_LIST()
220     }
221 };
222 
223 static const VMStateDescription vmstate_pci_status = {
224     .name = "pci_status",
225     .version_id = 1,
226     .minimum_version_id = 1,
227     .minimum_version_id_old = 1,
228     .pre_save = vmstate_pci_status_pre_save,
229     .fields      = (VMStateField []) {
230         VMSTATE_UINT32(up, struct pci_status),
231         VMSTATE_UINT32(down, struct pci_status),
232         VMSTATE_END_OF_LIST()
233     }
234 };
235 
236 static int acpi_load_old(QEMUFile *f, void *opaque, int version_id)
237 {
238     PIIX4PMState *s = opaque;
239     int ret, i;
240     uint16_t temp;
241 
242     ret = pci_device_load(&s->dev, f);
243     if (ret < 0) {
244         return ret;
245     }
246     qemu_get_be16s(f, &s->ar.pm1.evt.sts);
247     qemu_get_be16s(f, &s->ar.pm1.evt.en);
248     qemu_get_be16s(f, &s->ar.pm1.cnt.cnt);
249 
250     ret = vmstate_load_state(f, &vmstate_apm, &s->apm, 1);
251     if (ret) {
252         return ret;
253     }
254 
255     qemu_get_timer(f, s->ar.tmr.timer);
256     qemu_get_sbe64s(f, &s->ar.tmr.overflow_time);
257 
258     qemu_get_be16s(f, (uint16_t *)s->ar.gpe.sts);
259     for (i = 0; i < 3; i++) {
260         qemu_get_be16s(f, &temp);
261     }
262 
263     qemu_get_be16s(f, (uint16_t *)s->ar.gpe.en);
264     for (i = 0; i < 3; i++) {
265         qemu_get_be16s(f, &temp);
266     }
267 
268     ret = vmstate_load_state(f, &vmstate_pci_status, &s->pci0_status, 1);
269     return ret;
270 }
271 
272 /* qemu-kvm 1.2 uses version 3 but advertised as 2
273  * To support incoming qemu-kvm 1.2 migration, change version_id
274  * and minimum_version_id to 2 below (which breaks migration from
275  * qemu 1.2).
276  *
277  */
278 static const VMStateDescription vmstate_acpi = {
279     .name = "piix4_pm",
280     .version_id = 3,
281     .minimum_version_id = 3,
282     .minimum_version_id_old = 1,
283     .load_state_old = acpi_load_old,
284     .post_load = vmstate_acpi_post_load,
285     .fields      = (VMStateField []) {
286         VMSTATE_PCI_DEVICE(dev, PIIX4PMState),
287         VMSTATE_UINT16(ar.pm1.evt.sts, PIIX4PMState),
288         VMSTATE_UINT16(ar.pm1.evt.en, PIIX4PMState),
289         VMSTATE_UINT16(ar.pm1.cnt.cnt, PIIX4PMState),
290         VMSTATE_STRUCT(apm, PIIX4PMState, 0, vmstate_apm, APMState),
291         VMSTATE_TIMER(ar.tmr.timer, PIIX4PMState),
292         VMSTATE_INT64(ar.tmr.overflow_time, PIIX4PMState),
293         VMSTATE_STRUCT(ar.gpe, PIIX4PMState, 2, vmstate_gpe, ACPIGPE),
294         VMSTATE_STRUCT(pci0_status, PIIX4PMState, 2, vmstate_pci_status,
295                        struct pci_status),
296         VMSTATE_END_OF_LIST()
297     }
298 };
299 
300 static void acpi_piix_eject_slot(PIIX4PMState *s, unsigned slots)
301 {
302     BusChild *kid, *next;
303     BusState *bus = qdev_get_parent_bus(&s->dev.qdev);
304     int slot = ffs(slots) - 1;
305     bool slot_free = true;
306 
307     /* Mark request as complete */
308     s->pci0_status.down &= ~(1U << slot);
309 
310     QTAILQ_FOREACH_SAFE(kid, &bus->children, sibling, next) {
311         DeviceState *qdev = kid->child;
312         PCIDevice *dev = PCI_DEVICE(qdev);
313         PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(dev);
314         if (PCI_SLOT(dev->devfn) == slot) {
315             if (pc->no_hotplug) {
316                 slot_free = false;
317             } else {
318                 qdev_free(qdev);
319             }
320         }
321     }
322     if (slot_free) {
323         s->pci0_slot_device_present &= ~(1U << slot);
324     }
325 }
326 
327 static void piix4_update_hotplug(PIIX4PMState *s)
328 {
329     PCIDevice *dev = &s->dev;
330     BusState *bus = qdev_get_parent_bus(&dev->qdev);
331     BusChild *kid, *next;
332 
333     /* Execute any pending removes during reset */
334     while (s->pci0_status.down) {
335         acpi_piix_eject_slot(s, s->pci0_status.down);
336     }
337 
338     s->pci0_hotplug_enable = ~0;
339     s->pci0_slot_device_present = 0;
340 
341     QTAILQ_FOREACH_SAFE(kid, &bus->children, sibling, next) {
342         DeviceState *qdev = kid->child;
343         PCIDevice *pdev = PCI_DEVICE(qdev);
344         PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(pdev);
345         int slot = PCI_SLOT(pdev->devfn);
346 
347         if (pc->no_hotplug) {
348             s->pci0_hotplug_enable &= ~(1U << slot);
349         }
350 
351         s->pci0_slot_device_present |= (1U << slot);
352     }
353 }
354 
355 static void piix4_reset(void *opaque)
356 {
357     PIIX4PMState *s = opaque;
358     uint8_t *pci_conf = s->dev.config;
359 
360     pci_conf[0x58] = 0;
361     pci_conf[0x59] = 0;
362     pci_conf[0x5a] = 0;
363     pci_conf[0x5b] = 0;
364 
365     pci_conf[0x40] = 0x01; /* PM io base read only bit */
366     pci_conf[0x80] = 0;
367 
368     if (s->kvm_enabled) {
369         /* Mark SMM as already inited (until KVM supports SMM). */
370         pci_conf[0x5B] = 0x02;
371     }
372     piix4_update_hotplug(s);
373 }
374 
375 static void piix4_pm_powerdown_req(Notifier *n, void *opaque)
376 {
377     PIIX4PMState *s = container_of(n, PIIX4PMState, powerdown_notifier);
378 
379     assert(s != NULL);
380     acpi_pm1_evt_power_down(&s->ar);
381 }
382 
383 static void piix4_pm_machine_ready(Notifier *n, void *opaque)
384 {
385     PIIX4PMState *s = container_of(n, PIIX4PMState, machine_ready);
386     MemoryRegion *io_as = pci_address_space_io(&s->dev);
387     uint8_t *pci_conf;
388 
389     pci_conf = s->dev.config;
390     pci_conf[0x5f] = 0x10 |
391         (memory_region_present(io_as, 0x378) ? 0x80 : 0);
392     pci_conf[0x63] = 0x60;
393     pci_conf[0x67] = (memory_region_present(io_as, 0x3f8) ? 0x08 : 0) |
394         (memory_region_present(io_as, 0x2f8) ? 0x90 : 0);
395 }
396 
397 static int piix4_pm_initfn(PCIDevice *dev)
398 {
399     PIIX4PMState *s = DO_UPCAST(PIIX4PMState, dev, dev);
400     uint8_t *pci_conf;
401 
402     pci_conf = s->dev.config;
403     pci_conf[0x06] = 0x80;
404     pci_conf[0x07] = 0x02;
405     pci_conf[0x09] = 0x00;
406     pci_conf[0x3d] = 0x01; // interrupt pin 1
407 
408     /* APM */
409     apm_init(dev, &s->apm, apm_ctrl_changed, s);
410 
411     if (s->kvm_enabled) {
412         /* Mark SMM as already inited to prevent SMM from running.  KVM does not
413          * support SMM mode. */
414         pci_conf[0x5B] = 0x02;
415     }
416 
417     /* XXX: which specification is used ? The i82731AB has different
418        mappings */
419     pci_conf[0x90] = s->smb_io_base | 1;
420     pci_conf[0x91] = s->smb_io_base >> 8;
421     pci_conf[0xd2] = 0x09;
422     pm_smbus_init(&s->dev.qdev, &s->smb);
423     memory_region_set_enabled(&s->smb.io, pci_conf[0xd2] & 1);
424     memory_region_add_subregion(pci_address_space_io(dev),
425                                 s->smb_io_base, &s->smb.io);
426 
427     memory_region_init(&s->io, OBJECT(s), "piix4-pm", 64);
428     memory_region_set_enabled(&s->io, false);
429     memory_region_add_subregion(pci_address_space_io(dev),
430                                 0, &s->io);
431 
432     acpi_pm_tmr_init(&s->ar, pm_tmr_timer, &s->io);
433     acpi_pm1_evt_init(&s->ar, pm_tmr_timer, &s->io);
434     acpi_pm1_cnt_init(&s->ar, &s->io, s->s4_val);
435     acpi_gpe_init(&s->ar, GPE_LEN);
436 
437     s->powerdown_notifier.notify = piix4_pm_powerdown_req;
438     qemu_register_powerdown_notifier(&s->powerdown_notifier);
439 
440     s->machine_ready.notify = piix4_pm_machine_ready;
441     qemu_add_machine_init_done_notifier(&s->machine_ready);
442     qemu_register_reset(piix4_reset, s);
443 
444     piix4_acpi_system_hot_add_init(pci_address_space_io(dev), dev->bus, s);
445 
446     return 0;
447 }
448 
449 i2c_bus *piix4_pm_init(PCIBus *bus, int devfn, uint32_t smb_io_base,
450                        qemu_irq sci_irq, qemu_irq smi_irq,
451                        int kvm_enabled, FWCfgState *fw_cfg)
452 {
453     PCIDevice *dev;
454     PIIX4PMState *s;
455 
456     dev = pci_create(bus, devfn, "PIIX4_PM");
457     qdev_prop_set_uint32(&dev->qdev, "smb_io_base", smb_io_base);
458 
459     s = DO_UPCAST(PIIX4PMState, dev, dev);
460     s->irq = sci_irq;
461     s->smi_irq = smi_irq;
462     s->kvm_enabled = kvm_enabled;
463 
464     qdev_init_nofail(&dev->qdev);
465 
466     if (fw_cfg) {
467         uint8_t suspend[6] = {128, 0, 0, 129, 128, 128};
468         suspend[3] = 1 | ((!s->disable_s3) << 7);
469         suspend[4] = s->s4_val | ((!s->disable_s4) << 7);
470 
471         fw_cfg_add_file(fw_cfg, "etc/system-states", g_memdup(suspend, 6), 6);
472     }
473 
474     return s->smb.smbus;
475 }
476 
477 static Property piix4_pm_properties[] = {
478     DEFINE_PROP_UINT32("smb_io_base", PIIX4PMState, smb_io_base, 0),
479     DEFINE_PROP_UINT8("disable_s3", PIIX4PMState, disable_s3, 0),
480     DEFINE_PROP_UINT8("disable_s4", PIIX4PMState, disable_s4, 0),
481     DEFINE_PROP_UINT8("s4_val", PIIX4PMState, s4_val, 2),
482     DEFINE_PROP_END_OF_LIST(),
483 };
484 
485 static void piix4_pm_class_init(ObjectClass *klass, void *data)
486 {
487     DeviceClass *dc = DEVICE_CLASS(klass);
488     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
489 
490     k->no_hotplug = 1;
491     k->init = piix4_pm_initfn;
492     k->config_write = pm_write_config;
493     k->vendor_id = PCI_VENDOR_ID_INTEL;
494     k->device_id = PCI_DEVICE_ID_INTEL_82371AB_3;
495     k->revision = 0x03;
496     k->class_id = PCI_CLASS_BRIDGE_OTHER;
497     dc->desc = "PM";
498     dc->no_user = 1;
499     dc->vmsd = &vmstate_acpi;
500     dc->props = piix4_pm_properties;
501 }
502 
503 static const TypeInfo piix4_pm_info = {
504     .name          = "PIIX4_PM",
505     .parent        = TYPE_PCI_DEVICE,
506     .instance_size = sizeof(PIIX4PMState),
507     .class_init    = piix4_pm_class_init,
508 };
509 
510 static void piix4_pm_register_types(void)
511 {
512     type_register_static(&piix4_pm_info);
513 }
514 
515 type_init(piix4_pm_register_types)
516 
517 static uint64_t gpe_readb(void *opaque, hwaddr addr, unsigned width)
518 {
519     PIIX4PMState *s = opaque;
520     uint32_t val = acpi_gpe_ioport_readb(&s->ar, addr);
521 
522     PIIX4_DPRINTF("gpe read %" HWADDR_PRIx " == %" PRIu32 "\n", addr, val);
523     return val;
524 }
525 
526 static void gpe_writeb(void *opaque, hwaddr addr, uint64_t val,
527                        unsigned width)
528 {
529     PIIX4PMState *s = opaque;
530 
531     acpi_gpe_ioport_writeb(&s->ar, addr, val);
532     pm_update_sci(s);
533 
534     PIIX4_DPRINTF("gpe write %" HWADDR_PRIx " <== %" PRIu64 "\n", addr, val);
535 }
536 
537 static const MemoryRegionOps piix4_gpe_ops = {
538     .read = gpe_readb,
539     .write = gpe_writeb,
540     .valid.min_access_size = 1,
541     .valid.max_access_size = 4,
542     .impl.min_access_size = 1,
543     .impl.max_access_size = 1,
544     .endianness = DEVICE_LITTLE_ENDIAN,
545 };
546 
547 static uint64_t pci_read(void *opaque, hwaddr addr, unsigned int size)
548 {
549     PIIX4PMState *s = opaque;
550     uint32_t val = 0;
551 
552     switch (addr) {
553     case PCI_UP_BASE - PCI_HOTPLUG_ADDR:
554         /* Manufacture an "up" value to cause a device check on any hotplug
555          * slot with a device.  Extra device checks are harmless. */
556         val = s->pci0_slot_device_present & s->pci0_hotplug_enable;
557         PIIX4_DPRINTF("pci_up_read %" PRIu32 "\n", val);
558         break;
559     case PCI_DOWN_BASE - PCI_HOTPLUG_ADDR:
560         val = s->pci0_status.down;
561         PIIX4_DPRINTF("pci_down_read %" PRIu32 "\n", val);
562         break;
563     case PCI_EJ_BASE - PCI_HOTPLUG_ADDR:
564         /* No feature defined yet */
565         PIIX4_DPRINTF("pci_features_read %" PRIu32 "\n", val);
566         break;
567     case PCI_RMV_BASE - PCI_HOTPLUG_ADDR:
568         val = s->pci0_hotplug_enable;
569         break;
570     default:
571         break;
572     }
573 
574     return val;
575 }
576 
577 static void pci_write(void *opaque, hwaddr addr, uint64_t data,
578                       unsigned int size)
579 {
580     switch (addr) {
581     case PCI_EJ_BASE - PCI_HOTPLUG_ADDR:
582         acpi_piix_eject_slot(opaque, (uint32_t)data);
583         PIIX4_DPRINTF("pciej write %" HWADDR_PRIx " <== %" PRIu64 "\n",
584                       addr, data);
585         break;
586     default:
587         break;
588     }
589 }
590 
591 static const MemoryRegionOps piix4_pci_ops = {
592     .read = pci_read,
593     .write = pci_write,
594     .endianness = DEVICE_LITTLE_ENDIAN,
595     .valid = {
596         .min_access_size = 4,
597         .max_access_size = 4,
598     },
599 };
600 
601 static uint64_t cpu_status_read(void *opaque, hwaddr addr, unsigned int size)
602 {
603     PIIX4PMState *s = opaque;
604     CPUStatus *cpus = &s->gpe_cpu;
605     uint64_t val = cpus->sts[addr];
606 
607     return val;
608 }
609 
610 static void cpu_status_write(void *opaque, hwaddr addr, uint64_t data,
611                              unsigned int size)
612 {
613     /* TODO: implement VCPU removal on guest signal that CPU can be removed */
614 }
615 
616 static const MemoryRegionOps cpu_hotplug_ops = {
617     .read = cpu_status_read,
618     .write = cpu_status_write,
619     .endianness = DEVICE_LITTLE_ENDIAN,
620     .valid = {
621         .min_access_size = 1,
622         .max_access_size = 1,
623     },
624 };
625 
626 typedef enum {
627     PLUG,
628     UNPLUG,
629 } HotplugEventType;
630 
631 static void piix4_cpu_hotplug_req(PIIX4PMState *s, CPUState *cpu,
632                                   HotplugEventType action)
633 {
634     CPUStatus *g = &s->gpe_cpu;
635     ACPIGPE *gpe = &s->ar.gpe;
636     CPUClass *k = CPU_GET_CLASS(cpu);
637     int64_t cpu_id;
638 
639     assert(s != NULL);
640 
641     *gpe->sts = *gpe->sts | PIIX4_CPU_HOTPLUG_STATUS;
642     cpu_id = k->get_arch_id(CPU(cpu));
643     if (action == PLUG) {
644         g->sts[cpu_id / 8] |= (1 << (cpu_id % 8));
645     } else {
646         g->sts[cpu_id / 8] &= ~(1 << (cpu_id % 8));
647     }
648     pm_update_sci(s);
649 }
650 
651 static void piix4_cpu_added_req(Notifier *n, void *opaque)
652 {
653     PIIX4PMState *s = container_of(n, PIIX4PMState, cpu_added_notifier);
654 
655     piix4_cpu_hotplug_req(s, CPU(opaque), PLUG);
656 }
657 
658 static void piix4_init_cpu_status(CPUState *cpu, void *data)
659 {
660     CPUStatus *g = (CPUStatus *)data;
661     CPUClass *k = CPU_GET_CLASS(cpu);
662     int64_t id = k->get_arch_id(cpu);
663 
664     g_assert((id / 8) < PIIX4_PROC_LEN);
665     g->sts[id / 8] |= (1 << (id % 8));
666 }
667 
668 static int piix4_device_hotplug(DeviceState *qdev, PCIDevice *dev,
669                                 PCIHotplugState state);
670 
671 static void piix4_acpi_system_hot_add_init(MemoryRegion *parent,
672                                            PCIBus *bus, PIIX4PMState *s)
673 {
674     memory_region_init_io(&s->io_gpe, OBJECT(s), &piix4_gpe_ops, s,
675                           "acpi-gpe0", GPE_LEN);
676     memory_region_add_subregion(parent, GPE_BASE, &s->io_gpe);
677 
678     memory_region_init_io(&s->io_pci, OBJECT(s), &piix4_pci_ops, s,
679                           "acpi-pci-hotplug", PCI_HOTPLUG_SIZE);
680     memory_region_add_subregion(parent, PCI_HOTPLUG_ADDR,
681                                 &s->io_pci);
682     pci_bus_hotplug(bus, piix4_device_hotplug, &s->dev.qdev);
683 
684     qemu_for_each_cpu(piix4_init_cpu_status, &s->gpe_cpu);
685     memory_region_init_io(&s->io_cpu, OBJECT(s), &cpu_hotplug_ops, s,
686                           "acpi-cpu-hotplug", PIIX4_PROC_LEN);
687     memory_region_add_subregion(parent, PIIX4_PROC_BASE, &s->io_cpu);
688     s->cpu_added_notifier.notify = piix4_cpu_added_req;
689     qemu_register_cpu_added_notifier(&s->cpu_added_notifier);
690 }
691 
692 static void enable_device(PIIX4PMState *s, int slot)
693 {
694     s->ar.gpe.sts[0] |= PIIX4_PCI_HOTPLUG_STATUS;
695     s->pci0_slot_device_present |= (1U << slot);
696 }
697 
698 static void disable_device(PIIX4PMState *s, int slot)
699 {
700     s->ar.gpe.sts[0] |= PIIX4_PCI_HOTPLUG_STATUS;
701     s->pci0_status.down |= (1U << slot);
702 }
703 
704 static int piix4_device_hotplug(DeviceState *qdev, PCIDevice *dev,
705 				PCIHotplugState state)
706 {
707     int slot = PCI_SLOT(dev->devfn);
708     PIIX4PMState *s = DO_UPCAST(PIIX4PMState, dev,
709                                 PCI_DEVICE(qdev));
710 
711     /* Don't send event when device is enabled during qemu machine creation:
712      * it is present on boot, no hotplug event is necessary. We do send an
713      * event when the device is disabled later. */
714     if (state == PCI_COLDPLUG_ENABLED) {
715         s->pci0_slot_device_present |= (1U << slot);
716         return 0;
717     }
718 
719     if (state == PCI_HOTPLUG_ENABLED) {
720         enable_device(s, slot);
721     } else {
722         disable_device(s, slot);
723     }
724 
725     pm_update_sci(s);
726 
727     return 0;
728 }
729