qemu-e2k/hw/acpi/piix4.c

728 lines
21 KiB
C

/*
* ACPI implementation
*
* Copyright (c) 2006 Fabrice Bellard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 2 as published by the Free Software Foundation.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#include "hw/hw.h"
#include "hw/i386/pc.h"
#include "hw/isa/apm.h"
#include "hw/i2c/pm_smbus.h"
#include "hw/pci/pci.h"
#include "hw/acpi/acpi.h"
#include "sysemu/sysemu.h"
#include "qemu/range.h"
#include "exec/ioport.h"
#include "hw/nvram/fw_cfg.h"
#include "exec/address-spaces.h"
//#define DEBUG
#ifdef DEBUG
# define PIIX4_DPRINTF(format, ...) printf(format, ## __VA_ARGS__)
#else
# define PIIX4_DPRINTF(format, ...) do { } while (0)
#endif
#define GPE_BASE 0xafe0
#define GPE_LEN 4
#define PCI_HOTPLUG_ADDR 0xae00
#define PCI_HOTPLUG_SIZE 0x000f
#define PCI_UP_BASE 0xae00
#define PCI_DOWN_BASE 0xae04
#define PCI_EJ_BASE 0xae08
#define PCI_RMV_BASE 0xae0c
#define PIIX4_PROC_BASE 0xaf00
#define PIIX4_PROC_LEN 32
#define PIIX4_PCI_HOTPLUG_STATUS 2
#define PIIX4_CPU_HOTPLUG_STATUS 4
struct pci_status {
uint32_t up; /* deprecated, maintained for migration compatibility */
uint32_t down;
};
typedef struct CPUStatus {
uint8_t sts[PIIX4_PROC_LEN];
} CPUStatus;
typedef struct PIIX4PMState {
PCIDevice dev;
MemoryRegion io;
MemoryRegion io_gpe;
MemoryRegion io_pci;
MemoryRegion io_cpu;
ACPIREGS ar;
APMState apm;
PMSMBus smb;
uint32_t smb_io_base;
qemu_irq irq;
qemu_irq smi_irq;
int kvm_enabled;
Notifier machine_ready;
Notifier powerdown_notifier;
/* for pci hotplug */
struct pci_status pci0_status;
uint32_t pci0_hotplug_enable;
uint32_t pci0_slot_device_present;
uint8_t disable_s3;
uint8_t disable_s4;
uint8_t s4_val;
CPUStatus gpe_cpu;
Notifier cpu_added_notifier;
} PIIX4PMState;
static void piix4_acpi_system_hot_add_init(MemoryRegion *parent,
PCIBus *bus, PIIX4PMState *s);
#define ACPI_ENABLE 0xf1
#define ACPI_DISABLE 0xf0
static void pm_update_sci(PIIX4PMState *s)
{
int sci_level, pmsts;
pmsts = acpi_pm1_evt_get_sts(&s->ar);
sci_level = (((pmsts & s->ar.pm1.evt.en) &
(ACPI_BITMASK_RT_CLOCK_ENABLE |
ACPI_BITMASK_POWER_BUTTON_ENABLE |
ACPI_BITMASK_GLOBAL_LOCK_ENABLE |
ACPI_BITMASK_TIMER_ENABLE)) != 0) ||
(((s->ar.gpe.sts[0] & s->ar.gpe.en[0]) &
(PIIX4_PCI_HOTPLUG_STATUS | PIIX4_CPU_HOTPLUG_STATUS)) != 0);
qemu_set_irq(s->irq, sci_level);
/* schedule a timer interruption if needed */
acpi_pm_tmr_update(&s->ar, (s->ar.pm1.evt.en & ACPI_BITMASK_TIMER_ENABLE) &&
!(pmsts & ACPI_BITMASK_TIMER_STATUS));
}
static void pm_tmr_timer(ACPIREGS *ar)
{
PIIX4PMState *s = container_of(ar, PIIX4PMState, ar);
pm_update_sci(s);
}
static void apm_ctrl_changed(uint32_t val, void *arg)
{
PIIX4PMState *s = arg;
/* ACPI specs 3.0, 4.7.2.5 */
acpi_pm1_cnt_update(&s->ar, val == ACPI_ENABLE, val == ACPI_DISABLE);
if (s->dev.config[0x5b] & (1 << 1)) {
if (s->smi_irq) {
qemu_irq_raise(s->smi_irq);
}
}
}
static void pm_io_space_update(PIIX4PMState *s)
{
uint32_t pm_io_base;
pm_io_base = le32_to_cpu(*(uint32_t *)(s->dev.config + 0x40));
pm_io_base &= 0xffc0;
memory_region_transaction_begin();
memory_region_set_enabled(&s->io, s->dev.config[0x80] & 1);
memory_region_set_address(&s->io, pm_io_base);
memory_region_transaction_commit();
}
static void smbus_io_space_update(PIIX4PMState *s)
{
s->smb_io_base = le32_to_cpu(*(uint32_t *)(s->dev.config + 0x90));
s->smb_io_base &= 0xffc0;
memory_region_transaction_begin();
memory_region_set_enabled(&s->smb.io, s->dev.config[0xd2] & 1);
memory_region_set_address(&s->smb.io, s->smb_io_base);
memory_region_transaction_commit();
}
static void pm_write_config(PCIDevice *d,
uint32_t address, uint32_t val, int len)
{
pci_default_write_config(d, address, val, len);
if (range_covers_byte(address, len, 0x80) ||
ranges_overlap(address, len, 0x40, 4)) {
pm_io_space_update((PIIX4PMState *)d);
}
if (range_covers_byte(address, len, 0xd2) ||
ranges_overlap(address, len, 0x90, 4)) {
smbus_io_space_update((PIIX4PMState *)d);
}
}
static void vmstate_pci_status_pre_save(void *opaque)
{
struct pci_status *pci0_status = opaque;
PIIX4PMState *s = container_of(pci0_status, PIIX4PMState, pci0_status);
/* We no longer track up, so build a safe value for migrating
* to a version that still does... of course these might get lost
* by an old buggy implementation, but we try. */
pci0_status->up = s->pci0_slot_device_present & s->pci0_hotplug_enable;
}
static int vmstate_acpi_post_load(void *opaque, int version_id)
{
PIIX4PMState *s = opaque;
pm_io_space_update(s);
return 0;
}
#define VMSTATE_GPE_ARRAY(_field, _state) \
{ \
.name = (stringify(_field)), \
.version_id = 0, \
.info = &vmstate_info_uint16, \
.size = sizeof(uint16_t), \
.flags = VMS_SINGLE | VMS_POINTER, \
.offset = vmstate_offset_pointer(_state, _field, uint8_t), \
}
static const VMStateDescription vmstate_gpe = {
.name = "gpe",
.version_id = 1,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
.fields = (VMStateField []) {
VMSTATE_GPE_ARRAY(sts, ACPIGPE),
VMSTATE_GPE_ARRAY(en, ACPIGPE),
VMSTATE_END_OF_LIST()
}
};
static const VMStateDescription vmstate_pci_status = {
.name = "pci_status",
.version_id = 1,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
.pre_save = vmstate_pci_status_pre_save,
.fields = (VMStateField []) {
VMSTATE_UINT32(up, struct pci_status),
VMSTATE_UINT32(down, struct pci_status),
VMSTATE_END_OF_LIST()
}
};
static int acpi_load_old(QEMUFile *f, void *opaque, int version_id)
{
PIIX4PMState *s = opaque;
int ret, i;
uint16_t temp;
ret = pci_device_load(&s->dev, f);
if (ret < 0) {
return ret;
}
qemu_get_be16s(f, &s->ar.pm1.evt.sts);
qemu_get_be16s(f, &s->ar.pm1.evt.en);
qemu_get_be16s(f, &s->ar.pm1.cnt.cnt);
ret = vmstate_load_state(f, &vmstate_apm, &s->apm, 1);
if (ret) {
return ret;
}
qemu_get_timer(f, s->ar.tmr.timer);
qemu_get_sbe64s(f, &s->ar.tmr.overflow_time);
qemu_get_be16s(f, (uint16_t *)s->ar.gpe.sts);
for (i = 0; i < 3; i++) {
qemu_get_be16s(f, &temp);
}
qemu_get_be16s(f, (uint16_t *)s->ar.gpe.en);
for (i = 0; i < 3; i++) {
qemu_get_be16s(f, &temp);
}
ret = vmstate_load_state(f, &vmstate_pci_status, &s->pci0_status, 1);
return ret;
}
/* qemu-kvm 1.2 uses version 3 but advertised as 2
* To support incoming qemu-kvm 1.2 migration, change version_id
* and minimum_version_id to 2 below (which breaks migration from
* qemu 1.2).
*
*/
static const VMStateDescription vmstate_acpi = {
.name = "piix4_pm",
.version_id = 3,
.minimum_version_id = 3,
.minimum_version_id_old = 1,
.load_state_old = acpi_load_old,
.post_load = vmstate_acpi_post_load,
.fields = (VMStateField []) {
VMSTATE_PCI_DEVICE(dev, PIIX4PMState),
VMSTATE_UINT16(ar.pm1.evt.sts, PIIX4PMState),
VMSTATE_UINT16(ar.pm1.evt.en, PIIX4PMState),
VMSTATE_UINT16(ar.pm1.cnt.cnt, PIIX4PMState),
VMSTATE_STRUCT(apm, PIIX4PMState, 0, vmstate_apm, APMState),
VMSTATE_TIMER(ar.tmr.timer, PIIX4PMState),
VMSTATE_INT64(ar.tmr.overflow_time, PIIX4PMState),
VMSTATE_STRUCT(ar.gpe, PIIX4PMState, 2, vmstate_gpe, ACPIGPE),
VMSTATE_STRUCT(pci0_status, PIIX4PMState, 2, vmstate_pci_status,
struct pci_status),
VMSTATE_END_OF_LIST()
}
};
static void acpi_piix_eject_slot(PIIX4PMState *s, unsigned slots)
{
BusChild *kid, *next;
BusState *bus = qdev_get_parent_bus(&s->dev.qdev);
int slot = ffs(slots) - 1;
bool slot_free = true;
/* Mark request as complete */
s->pci0_status.down &= ~(1U << slot);
QTAILQ_FOREACH_SAFE(kid, &bus->children, sibling, next) {
DeviceState *qdev = kid->child;
PCIDevice *dev = PCI_DEVICE(qdev);
PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(dev);
if (PCI_SLOT(dev->devfn) == slot) {
if (pc->no_hotplug) {
slot_free = false;
} else {
qdev_free(qdev);
}
}
}
if (slot_free) {
s->pci0_slot_device_present &= ~(1U << slot);
}
}
static void piix4_update_hotplug(PIIX4PMState *s)
{
PCIDevice *dev = &s->dev;
BusState *bus = qdev_get_parent_bus(&dev->qdev);
BusChild *kid, *next;
/* Execute any pending removes during reset */
while (s->pci0_status.down) {
acpi_piix_eject_slot(s, s->pci0_status.down);
}
s->pci0_hotplug_enable = ~0;
s->pci0_slot_device_present = 0;
QTAILQ_FOREACH_SAFE(kid, &bus->children, sibling, next) {
DeviceState *qdev = kid->child;
PCIDevice *pdev = PCI_DEVICE(qdev);
PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(pdev);
int slot = PCI_SLOT(pdev->devfn);
if (pc->no_hotplug) {
s->pci0_hotplug_enable &= ~(1U << slot);
}
s->pci0_slot_device_present |= (1U << slot);
}
}
static void piix4_reset(void *opaque)
{
PIIX4PMState *s = opaque;
uint8_t *pci_conf = s->dev.config;
pci_conf[0x58] = 0;
pci_conf[0x59] = 0;
pci_conf[0x5a] = 0;
pci_conf[0x5b] = 0;
pci_conf[0x40] = 0x01; /* PM io base read only bit */
pci_conf[0x80] = 0;
if (s->kvm_enabled) {
/* Mark SMM as already inited (until KVM supports SMM). */
pci_conf[0x5B] = 0x02;
}
piix4_update_hotplug(s);
}
static void piix4_pm_powerdown_req(Notifier *n, void *opaque)
{
PIIX4PMState *s = container_of(n, PIIX4PMState, powerdown_notifier);
assert(s != NULL);
acpi_pm1_evt_power_down(&s->ar);
}
static void piix4_pm_machine_ready(Notifier *n, void *opaque)
{
PIIX4PMState *s = container_of(n, PIIX4PMState, machine_ready);
uint8_t *pci_conf;
pci_conf = s->dev.config;
pci_conf[0x5f] = (isa_is_ioport_assigned(0x378) ? 0x80 : 0) | 0x10;
pci_conf[0x63] = 0x60;
pci_conf[0x67] = (isa_is_ioport_assigned(0x3f8) ? 0x08 : 0) |
(isa_is_ioport_assigned(0x2f8) ? 0x90 : 0);
}
static int piix4_pm_initfn(PCIDevice *dev)
{
PIIX4PMState *s = DO_UPCAST(PIIX4PMState, dev, dev);
uint8_t *pci_conf;
pci_conf = s->dev.config;
pci_conf[0x06] = 0x80;
pci_conf[0x07] = 0x02;
pci_conf[0x09] = 0x00;
pci_conf[0x3d] = 0x01; // interrupt pin 1
/* APM */
apm_init(dev, &s->apm, apm_ctrl_changed, s);
if (s->kvm_enabled) {
/* Mark SMM as already inited to prevent SMM from running. KVM does not
* support SMM mode. */
pci_conf[0x5B] = 0x02;
}
/* XXX: which specification is used ? The i82731AB has different
mappings */
pci_conf[0x90] = s->smb_io_base | 1;
pci_conf[0x91] = s->smb_io_base >> 8;
pci_conf[0xd2] = 0x09;
pm_smbus_init(&s->dev.qdev, &s->smb);
memory_region_set_enabled(&s->smb.io, pci_conf[0xd2] & 1);
memory_region_add_subregion(pci_address_space_io(dev),
s->smb_io_base, &s->smb.io);
memory_region_init(&s->io, "piix4-pm", 64);
memory_region_set_enabled(&s->io, false);
memory_region_add_subregion(pci_address_space_io(dev),
0, &s->io);
acpi_pm_tmr_init(&s->ar, pm_tmr_timer, &s->io);
acpi_pm1_evt_init(&s->ar, pm_tmr_timer, &s->io);
acpi_pm1_cnt_init(&s->ar, &s->io, s->s4_val);
acpi_gpe_init(&s->ar, GPE_LEN);
s->powerdown_notifier.notify = piix4_pm_powerdown_req;
qemu_register_powerdown_notifier(&s->powerdown_notifier);
s->machine_ready.notify = piix4_pm_machine_ready;
qemu_add_machine_init_done_notifier(&s->machine_ready);
qemu_register_reset(piix4_reset, s);
piix4_acpi_system_hot_add_init(pci_address_space_io(dev), dev->bus, s);
return 0;
}
i2c_bus *piix4_pm_init(PCIBus *bus, int devfn, uint32_t smb_io_base,
qemu_irq sci_irq, qemu_irq smi_irq,
int kvm_enabled, void *fw_cfg)
{
PCIDevice *dev;
PIIX4PMState *s;
dev = pci_create(bus, devfn, "PIIX4_PM");
qdev_prop_set_uint32(&dev->qdev, "smb_io_base", smb_io_base);
s = DO_UPCAST(PIIX4PMState, dev, dev);
s->irq = sci_irq;
s->smi_irq = smi_irq;
s->kvm_enabled = kvm_enabled;
qdev_init_nofail(&dev->qdev);
if (fw_cfg) {
uint8_t suspend[6] = {128, 0, 0, 129, 128, 128};
suspend[3] = 1 | ((!s->disable_s3) << 7);
suspend[4] = s->s4_val | ((!s->disable_s4) << 7);
fw_cfg_add_file(fw_cfg, "etc/system-states", g_memdup(suspend, 6), 6);
}
return s->smb.smbus;
}
static Property piix4_pm_properties[] = {
DEFINE_PROP_UINT32("smb_io_base", PIIX4PMState, smb_io_base, 0),
DEFINE_PROP_UINT8("disable_s3", PIIX4PMState, disable_s3, 0),
DEFINE_PROP_UINT8("disable_s4", PIIX4PMState, disable_s4, 0),
DEFINE_PROP_UINT8("s4_val", PIIX4PMState, s4_val, 2),
DEFINE_PROP_END_OF_LIST(),
};
static void piix4_pm_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
k->no_hotplug = 1;
k->init = piix4_pm_initfn;
k->config_write = pm_write_config;
k->vendor_id = PCI_VENDOR_ID_INTEL;
k->device_id = PCI_DEVICE_ID_INTEL_82371AB_3;
k->revision = 0x03;
k->class_id = PCI_CLASS_BRIDGE_OTHER;
dc->desc = "PM";
dc->no_user = 1;
dc->vmsd = &vmstate_acpi;
dc->props = piix4_pm_properties;
}
static const TypeInfo piix4_pm_info = {
.name = "PIIX4_PM",
.parent = TYPE_PCI_DEVICE,
.instance_size = sizeof(PIIX4PMState),
.class_init = piix4_pm_class_init,
};
static void piix4_pm_register_types(void)
{
type_register_static(&piix4_pm_info);
}
type_init(piix4_pm_register_types)
static uint64_t gpe_readb(void *opaque, hwaddr addr, unsigned width)
{
PIIX4PMState *s = opaque;
uint32_t val = acpi_gpe_ioport_readb(&s->ar, addr);
PIIX4_DPRINTF("gpe read %x == %x\n", addr, val);
return val;
}
static void gpe_writeb(void *opaque, hwaddr addr, uint64_t val,
unsigned width)
{
PIIX4PMState *s = opaque;
acpi_gpe_ioport_writeb(&s->ar, addr, val);
pm_update_sci(s);
PIIX4_DPRINTF("gpe write %x <== %d\n", addr, val);
}
static const MemoryRegionOps piix4_gpe_ops = {
.read = gpe_readb,
.write = gpe_writeb,
.valid.min_access_size = 1,
.valid.max_access_size = 4,
.impl.min_access_size = 1,
.impl.max_access_size = 1,
.endianness = DEVICE_LITTLE_ENDIAN,
};
static uint64_t pci_read(void *opaque, hwaddr addr, unsigned int size)
{
PIIX4PMState *s = opaque;
uint32_t val = 0;
switch (addr) {
case PCI_UP_BASE - PCI_HOTPLUG_ADDR:
/* Manufacture an "up" value to cause a device check on any hotplug
* slot with a device. Extra device checks are harmless. */
val = s->pci0_slot_device_present & s->pci0_hotplug_enable;
PIIX4_DPRINTF("pci_up_read %x\n", val);
break;
case PCI_DOWN_BASE - PCI_HOTPLUG_ADDR:
val = s->pci0_status.down;
PIIX4_DPRINTF("pci_down_read %x\n", val);
break;
case PCI_EJ_BASE - PCI_HOTPLUG_ADDR:
/* No feature defined yet */
PIIX4_DPRINTF("pci_features_read %x\n", val);
break;
case PCI_RMV_BASE - PCI_HOTPLUG_ADDR:
val = s->pci0_hotplug_enable;
break;
default:
break;
}
return val;
}
static void pci_write(void *opaque, hwaddr addr, uint64_t data,
unsigned int size)
{
switch (addr) {
case PCI_EJ_BASE - PCI_HOTPLUG_ADDR:
acpi_piix_eject_slot(opaque, (uint32_t)data);
PIIX4_DPRINTF("pciej write %" HWADDR_PRIx " <== % " PRIu64 "\n",
addr, data);
break;
default:
break;
}
}
static const MemoryRegionOps piix4_pci_ops = {
.read = pci_read,
.write = pci_write,
.endianness = DEVICE_LITTLE_ENDIAN,
.valid = {
.min_access_size = 4,
.max_access_size = 4,
},
};
static uint64_t cpu_status_read(void *opaque, hwaddr addr, unsigned int size)
{
PIIX4PMState *s = opaque;
CPUStatus *cpus = &s->gpe_cpu;
uint64_t val = cpus->sts[addr];
return val;
}
static void cpu_status_write(void *opaque, hwaddr addr, uint64_t data,
unsigned int size)
{
/* TODO: implement VCPU removal on guest signal that CPU can be removed */
}
static const MemoryRegionOps cpu_hotplug_ops = {
.read = cpu_status_read,
.write = cpu_status_write,
.endianness = DEVICE_LITTLE_ENDIAN,
.valid = {
.min_access_size = 1,
.max_access_size = 1,
},
};
typedef enum {
PLUG,
UNPLUG,
} HotplugEventType;
static void piix4_cpu_hotplug_req(PIIX4PMState *s, CPUState *cpu,
HotplugEventType action)
{
CPUStatus *g = &s->gpe_cpu;
ACPIGPE *gpe = &s->ar.gpe;
CPUClass *k = CPU_GET_CLASS(cpu);
int64_t cpu_id;
assert(s != NULL);
*gpe->sts = *gpe->sts | PIIX4_CPU_HOTPLUG_STATUS;
cpu_id = k->get_arch_id(CPU(cpu));
if (action == PLUG) {
g->sts[cpu_id / 8] |= (1 << (cpu_id % 8));
} else {
g->sts[cpu_id / 8] &= ~(1 << (cpu_id % 8));
}
pm_update_sci(s);
}
static void piix4_cpu_added_req(Notifier *n, void *opaque)
{
PIIX4PMState *s = container_of(n, PIIX4PMState, cpu_added_notifier);
piix4_cpu_hotplug_req(s, CPU(opaque), PLUG);
}
static void piix4_init_cpu_status(CPUState *cpu, void *data)
{
CPUStatus *g = (CPUStatus *)data;
CPUClass *k = CPU_GET_CLASS(cpu);
int64_t id = k->get_arch_id(cpu);
g_assert((id / 8) < PIIX4_PROC_LEN);
g->sts[id / 8] |= (1 << (id % 8));
}
static int piix4_device_hotplug(DeviceState *qdev, PCIDevice *dev,
PCIHotplugState state);
static void piix4_acpi_system_hot_add_init(MemoryRegion *parent,
PCIBus *bus, PIIX4PMState *s)
{
memory_region_init_io(&s->io_gpe, &piix4_gpe_ops, s, "apci-gpe0",
GPE_LEN);
memory_region_add_subregion(parent, GPE_BASE, &s->io_gpe);
memory_region_init_io(&s->io_pci, &piix4_pci_ops, s, "apci-pci-hotplug",
PCI_HOTPLUG_SIZE);
memory_region_add_subregion(parent, PCI_HOTPLUG_ADDR,
&s->io_pci);
pci_bus_hotplug(bus, piix4_device_hotplug, &s->dev.qdev);
qemu_for_each_cpu(piix4_init_cpu_status, &s->gpe_cpu);
memory_region_init_io(&s->io_cpu, &cpu_hotplug_ops, s, "apci-cpu-hotplug",
PIIX4_PROC_LEN);
memory_region_add_subregion(parent, PIIX4_PROC_BASE, &s->io_cpu);
s->cpu_added_notifier.notify = piix4_cpu_added_req;
qemu_register_cpu_added_notifier(&s->cpu_added_notifier);
}
static void enable_device(PIIX4PMState *s, int slot)
{
s->ar.gpe.sts[0] |= PIIX4_PCI_HOTPLUG_STATUS;
s->pci0_slot_device_present |= (1U << slot);
}
static void disable_device(PIIX4PMState *s, int slot)
{
s->ar.gpe.sts[0] |= PIIX4_PCI_HOTPLUG_STATUS;
s->pci0_status.down |= (1U << slot);
}
static int piix4_device_hotplug(DeviceState *qdev, PCIDevice *dev,
PCIHotplugState state)
{
int slot = PCI_SLOT(dev->devfn);
PIIX4PMState *s = DO_UPCAST(PIIX4PMState, dev,
PCI_DEVICE(qdev));
/* Don't send event when device is enabled during qemu machine creation:
* it is present on boot, no hotplug event is necessary. We do send an
* event when the device is disabled later. */
if (state == PCI_COLDPLUG_ENABLED) {
s->pci0_slot_device_present |= (1U << slot);
return 0;
}
if (state == PCI_HOTPLUG_ENABLED) {
enable_device(s, slot);
} else {
disable_device(s, slot);
}
pm_update_sci(s);
return 0;
}