qemu vl.cソース学習

27802 ワード

コードバージョンqemu 1.5,linuxの下でkvmを使って加速したものだけを見て、guestはx 86です.
vl.c:main
atexit(qemu_run_exit_notifiers);
vl.c,登録atexit関数,遍歴exit_notifiers、各nodeのnotify関数を実行

static void qemu_run_exit_notifiers(void)
{
    notifier_list_notify(&exit_notifiers, NULL);
}

void notifier_list_notify(NotifierList *list, void *data)
{
    Notifier *notifier, *next;

    QLIST_FOREACH_SAFE(notifier, &list->notifiers, node, next) {
        notifier->notify(notifier, data);
    }
}

typedef struct NotifierList
{
    QLIST_HEAD(, Notifier) notifiers;
} NotifierList;

struct Notifier
{
    void (*notify)(Notifier *notifier, void *data);
    QLIST_ENTRY(Notifier) node;
};

exit_notifiersはどこから来たのですか.

static NotifierList exit_notifiers =
    NOTIFIER_LIST_INITIALIZER(exit_notifiers);

#define NOTIFIER_LIST_INITIALIZER(head) \
    { QLIST_HEAD_INITIALIZER((head).notifiers) }

void qemu_add_exit_notifier(Notifier *notify)
{
    notifier_list_add(&exit_notifiers, notify);
}

error_set_progname(argv[0]);
Qemu-error.c,prognameをbasenameに設定する:

/*
 * Set the program name for error_print_loc().
 */
void error_set_progname(const char *argv0)
{
    const char *p = strrchr(argv0, '/');
    progname = p ? p + 1 : argv0;
}

g_mem_set_vtable(&mem_trace);

g_mem_set_vtable(&mem_trace);
    if (!g_thread_supported()) {
#if !GLIB_CHECK_VERSION(2, 31, 0)
        g_thread_init(NULL);
#else
        fprintf(stderr, "glib threading failed to initialize.
");
        exit(1);
#endif
    }

g_mem_set_vtableはhook mallocとfreeに使用され、廃棄されました.https://developer.gnome.org/glib/stable/glib-Memory-Allocation.html
g_thread_Initもいらない:The GLib threading system used to be initialized with g_thread_init(). This is no longer necessary. Since version 2.32, the GLib threading system is automatically initialized at the start of your program, and all thread-creation functions and synchronization primitives are available right away.
https://developer.gnome.org/glib/stable/glib-Threads.html#g-mutex-init
module_call_init(MODULE_INIT_QOM);
『qemu QOM(qemu object model)とデバイスシミュレーション』を参照
runstate_init();
ある運転状態から別の運転状態に切り替えることができるかどうか

static void runstate_init(void)
{
    const RunStateTransition *p;

    memset(&runstate_valid_transitions, 0, sizeof(runstate_valid_transitions));

    for (p = &runstate_transitions_def[0]; p->from != RUN_STATE_MAX; p++) {
        runstate_valid_transitions[p->from][p->to] = true;
    }
}

static bool runstate_valid_transitions[RUN_STATE_MAX][RUN_STATE_MAX];

static const RunStateTransition runstate_transitions_def[] = {
    /*     from      ->     to      */
    { RUN_STATE_DEBUG, RUN_STATE_RUNNING },

    { RUN_STATE_INMIGRATE, RUN_STATE_RUNNING },
    { RUN_STATE_INMIGRATE, RUN_STATE_PAUSED },

    { RUN_STATE_INTERNAL_ERROR, RUN_STATE_PAUSED },
    { RUN_STATE_INTERNAL_ERROR, RUN_STATE_FINISH_MIGRATE },

    { RUN_STATE_IO_ERROR, RUN_STATE_RUNNING },
    { RUN_STATE_IO_ERROR, RUN_STATE_FINISH_MIGRATE },

    { RUN_STATE_PAUSED, RUN_STATE_RUNNING },
    { RUN_STATE_PAUSED, RUN_STATE_FINISH_MIGRATE },

    { RUN_STATE_POSTMIGRATE, RUN_STATE_RUNNING },
    { RUN_STATE_POSTMIGRATE, RUN_STATE_FINISH_MIGRATE },

    { RUN_STATE_PRELAUNCH, RUN_STATE_RUNNING },
    { RUN_STATE_PRELAUNCH, RUN_STATE_FINISH_MIGRATE },
    { RUN_STATE_PRELAUNCH, RUN_STATE_INMIGRATE },

    { RUN_STATE_FINISH_MIGRATE, RUN_STATE_RUNNING },
    { RUN_STATE_FINISH_MIGRATE, RUN_STATE_POSTMIGRATE },

    { RUN_STATE_RESTORE_VM, RUN_STATE_RUNNING },

    { RUN_STATE_RUNNING, RUN_STATE_DEBUG },
    { RUN_STATE_RUNNING, RUN_STATE_INTERNAL_ERROR },
    { RUN_STATE_RUNNING, RUN_STATE_IO_ERROR },
    { RUN_STATE_RUNNING, RUN_STATE_PAUSED },
    { RUN_STATE_RUNNING, RUN_STATE_FINISH_MIGRATE },
    { RUN_STATE_RUNNING, RUN_STATE_RESTORE_VM },
    { RUN_STATE_RUNNING, RUN_STATE_SAVE_VM },
    { RUN_STATE_RUNNING, RUN_STATE_SHUTDOWN },
    { RUN_STATE_RUNNING, RUN_STATE_WATCHDOG },
    { RUN_STATE_RUNNING, RUN_STATE_GUEST_PANICKED },

    { RUN_STATE_SAVE_VM, RUN_STATE_RUNNING },

    { RUN_STATE_SHUTDOWN, RUN_STATE_PAUSED },
    { RUN_STATE_SHUTDOWN, RUN_STATE_FINISH_MIGRATE },

    { RUN_STATE_DEBUG, RUN_STATE_SUSPENDED },
    { RUN_STATE_RUNNING, RUN_STATE_SUSPENDED },
    { RUN_STATE_SUSPENDED, RUN_STATE_RUNNING },
    { RUN_STATE_SUSPENDED, RUN_STATE_FINISH_MIGRATE },

    { RUN_STATE_WATCHDOG, RUN_STATE_RUNNING },
    { RUN_STATE_WATCHDOG, RUN_STATE_FINISH_MIGRATE },

    { RUN_STATE_GUEST_PANICKED, RUN_STATE_PAUSED },
    { RUN_STATE_GUEST_PANICKED, RUN_STATE_FINISH_MIGRATE },

    { RUN_STATE_MAX, RUN_STATE_MAX },
};

init_clocks();
rtc_clock = host_clock;

void init_clocks(void)
{
    if (!rt_clock) {
        rt_clock = qemu_new_clock(QEMU_CLOCK_REALTIME);
        vm_clock = qemu_new_clock(QEMU_CLOCK_VIRTUAL);
        host_clock = qemu_new_clock(QEMU_CLOCK_HOST);
    }
}

static QEMUClock *qemu_new_clock(int type)
{
    QEMUClock *clock;

    clock = g_malloc0(sizeof(QEMUClock));
    clock->type = type;
    clock->enabled = true;
    clock->last = INT64_MIN;
    notifier_list_init(&clock->reset_notifiers);
    return clock;
}

os_setup_early_signal_handling();
無視できるsignalをすべて無視

void os_setup_early_signal_handling(void)
{
    struct sigaction act;
    sigfillset(&act.sa_mask);
    act.sa_flags = 0;
    act.sa_handler = SIG_IGN;
    sigaction(SIGPIPE, &act, NULL);
}

module_call_init(MODULE_INIT_MACHINE);
ここでpc_piix.cにはいくつかのMachineのモデルがfirst_に登録されています.machineチェーンテーブル:

static void pc_machine_init(void)
{
    qemu_register_machine(&pc_i440fx_machine_v1_5);
    qemu_register_machine(&pc_i440fx_machine_v1_4);
    qemu_register_machine(&pc_machine_v1_3);
    qemu_register_machine(&pc_machine_v1_2);
    qemu_register_machine(&pc_machine_v1_1);
    qemu_register_machine(&pc_machine_v1_0);
    qemu_register_machine(&pc_machine_v0_15);
    qemu_register_machine(&pc_machine_v0_14);
    qemu_register_machine(&pc_machine_v0_13);
    qemu_register_machine(&pc_machine_v0_12);
    qemu_register_machine(&pc_machine_v0_11);
    qemu_register_machine(&pc_machine_v0_10);
    qemu_register_machine(&isapc_machine);
#ifdef CONFIG_XEN
    qemu_register_machine(&xenfv_machine);
#endif
}

machine_init(pc_machine_init);

チェーンテーブルの最後に追加

static QEMUMachine *first_machine = NULL;
QEMUMachine *current_machine = NULL;

int qemu_register_machine(QEMUMachine *m)
{
    QEMUMachine **pm;
    pm = &first_machine;
    while (*pm != NULL)
        pm = &(*pm)->next;
    m->next = NULL;
    *pm = m;
    return 0;
}

初期化関数はpc_であることに注意してください.init_pci、中はpcを呼び出しましたinit1:

static QEMUMachine pc_i440fx_machine_v1_5 = {
    .name = "pc-i440fx-1.5",
    .alias = "pc",
    .desc = "Standard PC (i440FX + PIIX, 1996)",
    .init = pc_init_pci,
    .hot_add_cpu = pc_hot_add_cpu,
    .max_cpus = 255,
    .is_default = 1,
    DEFAULT_MACHINE_OPTIONS,
};

machine = find_default_machine();
PC-i 440 fx-1.5はチェーンテーブルの前にあり、is_default=1なのでデフォルトMachineとして選択

QEMUMachine *find_default_machine(void)
{
    QEMUMachine *m;

    for(m = first_machine; m != NULL; m = m->next) {
        if (m->is_default) {
            return m;
        }
    }
    return NULL;
}

パラメータ解析
デフォルトのプロファイルを使用するか、ユーザーが指定したプロファイルを使用するかを2回確認します.2回目は完全なパラメータ解析です
『qemuパラメータ解析』
qemu_init_main_loop()
clock,timer,signal,aioを初期化
configure_accelerator();
アクセラレータにはxen,kvm,tcgがあります

static int configure_accelerator(void)
{
    const char *p = NULL;
    char buf[10];
    int i, ret;
    bool accel_initialised = false;
    bool init_failed = false;

    QemuOptsList *list = qemu_find_opts("machine");
    if (!QTAILQ_EMPTY(&list->head)) {
        p = qemu_opt_get(QTAILQ_FIRST(&list->head), "accel");
    }

    if (p == NULL) {
        /* Use the default "accelerator", tcg */
        p = "tcg";
    }

    while (!accel_initialised && *p != '\0') {
        if (*p == ':') {
            p++;
        }
        p = get_opt_name(buf, sizeof (buf), p, ':');
        for (i = 0; i < ARRAY_SIZE(accel_list); i++) {
            if (strcmp(accel_list[i].opt_name, buf) == 0) {
                if (!accel_list[i].available()) {
                    printf("%s not supported for this target
",
                           accel_list[i].name);
                    continue;
                }
                *(accel_list[i].allowed) = true;
                ret = accel_list[i].init();
                if (ret < 0) {
                    init_failed = true;
                    fprintf(stderr, "failed to initialize %s: %s
",
                            accel_list[i].name,
                            strerror(-ret));
                    *(accel_list[i].allowed) = false;
                } else {
                    accel_initialised = true;
                }
                break;
            }
        }
        if (i == ARRAY_SIZE(accel_list)) {
            fprintf(stderr, "\"%s\" accelerator does not exist.
", buf);
        }
    }

    if (!accel_initialised) {
        if (!init_failed) {
            fprintf(stderr, "No accelerator found!
");
        }
        exit(1);
    }

    if (init_failed) {
        fprintf(stderr, "Back to %s accelerator.
", accel_list[i].name);
    }

    return !accel_initialised;
}

static struct {
    const char *opt_name;
    const char *name;
    int (*available)(void);
    int (*init)(void);
    bool *allowed;
} accel_list[] = {
    { "tcg", "tcg", tcg_available, tcg_init, &tcg_allowed },
    { "xen", "Xen", xen_available, xen_init, &xen_allowed },
    { "kvm", "KVM", kvm_available, kvm_init, &kvm_allowed },
    { "qtest", "QTest", qtest_available, qtest_init, &qtest_allowed },
};

machineのaccelの構成に従って、kvm_などのaccelの初期化関数を呼び出します.init、vmを作成し、extensionsをたくさんチェックし、他の操作もいくつかあります.ここでvCPUを作成していないことに注意してください.

int kvm_init(void)
{
    static const char upgrade_note[] =
        "Please upgrade to at least kernel 2.6.29 or recent kvm-kmod
"
        "(see http://sourceforge.net/projects/kvm).
";
    KVMState *s;
    const KVMCapabilityInfo *missing_cap;
    int ret;
    int i;
    int max_vcpus;

    s = g_malloc0(sizeof(KVMState));

    /*
     * On systems where the kernel can support different base page
     * sizes, host page size may be different from TARGET_PAGE_SIZE,
     * even with KVM.  TARGET_PAGE_SIZE is assumed to be the minimum
     * page size for the system though.
     */
    assert(TARGET_PAGE_SIZE <= getpagesize());

#ifdef KVM_CAP_SET_GUEST_DEBUG
    QTAILQ_INIT(&s->kvm_sw_breakpoints);
#endif
    for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
        s->slots[i].slot = i;
    }
    s->vmfd = -1;
    s->fd = qemu_open("/dev/kvm", O_RDWR);
    if (s->fd == -1) {
        fprintf(stderr, "Could not access KVM kernel module: %m
");
        ret = -errno;
        goto err;
    }

    ret = kvm_ioctl(s, KVM_GET_API_VERSION, 0);
    if (ret < KVM_API_VERSION) {
        if (ret > 0) {
            ret = -EINVAL;
        }
        fprintf(stderr, "kvm version too old
");
        goto err;
    }

    if (ret > KVM_API_VERSION) {
        ret = -EINVAL;
        fprintf(stderr, "kvm version not supported
");
        goto err;
    }

    max_vcpus = kvm_max_vcpus(s);
    if (smp_cpus > max_vcpus) {
        ret = -EINVAL;
        fprintf(stderr, "Number of SMP cpus requested (%d) exceeds max cpus "
                "supported by KVM (%d)
", smp_cpus, max_vcpus);
        goto err;
    }

    s->vmfd = kvm_ioctl(s, KVM_CREATE_VM, 0);
    if (s->vmfd < 0) {
#ifdef TARGET_S390X
        fprintf(stderr, "Please add the 'switch_amode' kernel parameter to "
                        "your host kernel command line
");
#endif
        ret = s->vmfd;
        goto err;
    }

    missing_cap = kvm_check_extension_list(s, kvm_required_capabilites);
    if (!missing_cap) {
        missing_cap =
            kvm_check_extension_list(s, kvm_arch_required_capabilities);
    }
    if (missing_cap) {
        ret = -EINVAL;
        fprintf(stderr, "kvm does not support %s
%s",
                missing_cap->name, upgrade_note);
        goto err;
    }

    s->coalesced_mmio = kvm_check_extension(s, KVM_CAP_COALESCED_MMIO);

    s->broken_set_mem_region = 1;
    ret = kvm_check_extension(s, KVM_CAP_JOIN_MEMORY_REGIONS_WORKS);
    if (ret > 0) {
        s->broken_set_mem_region = 0;
    }

#ifdef KVM_CAP_VCPU_EVENTS
    s->vcpu_events = kvm_check_extension(s, KVM_CAP_VCPU_EVENTS);
#endif

    s->robust_singlestep =
        kvm_check_extension(s, KVM_CAP_X86_ROBUST_SINGLESTEP);

#ifdef KVM_CAP_DEBUGREGS
    s->debugregs = kvm_check_extension(s, KVM_CAP_DEBUGREGS);
#endif

#ifdef KVM_CAP_XSAVE
    s->xsave = kvm_check_extension(s, KVM_CAP_XSAVE);
#endif

#ifdef KVM_CAP_XCRS
    s->xcrs = kvm_check_extension(s, KVM_CAP_XCRS);
#endif

#ifdef KVM_CAP_PIT_STATE2
    s->pit_state2 = kvm_check_extension(s, KVM_CAP_PIT_STATE2);
#endif

#ifdef KVM_CAP_IRQ_ROUTING
    s->direct_msi = (kvm_check_extension(s, KVM_CAP_SIGNAL_MSI) > 0);
#endif

    s->intx_set_mask = kvm_check_extension(s, KVM_CAP_PCI_2_3);

    s->irq_set_ioctl = KVM_IRQ_LINE;
    if (kvm_check_extension(s, KVM_CAP_IRQ_INJECT_STATUS)) {
        s->irq_set_ioctl = KVM_IRQ_LINE_STATUS;
    }

    ret = kvm_arch_init(s);
    if (ret < 0) {
        goto err;
    }

    ret = kvm_irqchip_create(s);
    if (ret < 0) {
        goto err;
    }

    kvm_state = s;
    memory_listener_register(&kvm_memory_listener, &address_space_memory);
    memory_listener_register(&kvm_io_listener, &address_space_io);

    s->many_ioeventfds = kvm_check_many_ioeventfds();

    cpu_interrupt_handler = kvm_handle_interrupt;

    return 0;

err:
    if (s->vmfd >= 0) {
        close(s->vmfd);
    }
    if (s->fd != -1) {
        close(s->fd);
    }
    g_free(s);

    return ret;
}

os_set_line_buffering();
stdoutを行バッファに設定します.つまり、各行をリフレッシュします.

void os_set_line_buffering(void)
{
    setvbuf(stdout, NULL, _IOLBF, 0);
}

cpu_exec_init_all();
メモリの初期化
『android qemu-kvmメモリ管理とIOマッピング』

void cpu_exec_init_all(void)
{
#if !defined(CONFIG_USER_ONLY)
    qemu_mutex_init(&ram_list.mutex);
    memory_map_init();
    io_mem_init();
#endif
}

machine->init(&args);

QEMUMachineInitArgs args = { .ram_size = ram_size,
                                 .boot_device = (boot_devices[0] == '\0') ?
                                                machine->boot_order :
                                                boot_devices,
                                 .kernel_filename = kernel_filename,
                                 .kernel_cmdline = kernel_cmdline,
                                 .initrd_filename = initrd_filename,
                                 .cpu_model = cpu_model };
machine->init(&args);

pc_の実行init_pci,pc_init1 inside

static void pc_init_pci(QEMUMachineInitArgs *args)
{
    ram_addr_t ram_size = args->ram_size;
    const char *cpu_model = args->cpu_model;
    const char *kernel_filename = args->kernel_filename;
    const char *kernel_cmdline = args->kernel_cmdline;
    const char *initrd_filename = args->initrd_filename;
    const char *boot_device = args->boot_device;
    pc_init1(get_system_memory(),
             get_system_io(),
             ram_size, boot_device,
             kernel_filename, kernel_cmdline,
             initrd_filename, cpu_model, 1, 1);
}

pci bus,isa bus,8254,8259などの初期化が行われ、vCPUスレッドが作成される

static void pc_init1(MemoryRegion *system_memory,
                     MemoryRegion *system_io,
                     ram_addr_t ram_size,
                     const char *boot_device,
                     const char *kernel_filename,
                     const char *kernel_cmdline,
                     const char *initrd_filename,
                     const char *cpu_model,
                     int pci_enabled,
                     int kvmclock_enabled)
{
    int i;
    ram_addr_t below_4g_mem_size, above_4g_mem_size;
    PCIBus *pci_bus;
    ISABus *isa_bus;
    PCII440FXState *i440fx_state;
    int piix3_devfn = -1;
    qemu_irq *cpu_irq;
    qemu_irq *gsi;
    qemu_irq *i8259;
    qemu_irq *smi_irq;
    GSIState *gsi_state;
    DriveInfo *hd[MAX_IDE_BUS * MAX_IDE_DEVS];
    BusState *idebus[MAX_IDE_BUS];
    ISADevice *rtc_state;
    ISADevice *floppy;
    MemoryRegion *ram_memory;
    MemoryRegion *pci_memory;
    MemoryRegion *rom_memory;
    DeviceState *icc_bridge;
    void *fw_cfg = NULL;

    icc_bridge = qdev_create(NULL, TYPE_ICC_BRIDGE);
    object_property_add_child(qdev_get_machine(), "icc-bridge",
                              OBJECT(icc_bridge), NULL);

    pc_cpus_init(cpu_model, icc_bridge);
    pc_acpi_init("acpi-dsdt.aml");

    if (kvmclock_enabled) {
        kvmclock_create();
    }

    if (ram_size >= QEMU_BELOW_4G_RAM_END ) {
        above_4g_mem_size = ram_size - QEMU_BELOW_4G_RAM_END;
        below_4g_mem_size = QEMU_BELOW_4G_RAM_END;
    } else {
        above_4g_mem_size = 0;
        below_4g_mem_size = ram_size;
    }

    if (pci_enabled) {
        pci_memory = g_new(MemoryRegion, 1);
        memory_region_init(pci_memory, "pci", INT64_MAX);
        rom_memory = pci_memory;
    } else {
        pci_memory = NULL;
        rom_memory = system_memory;
    }

    /* allocate ram and load rom/bios */
    if (!xen_enabled()) {
        fw_cfg = pc_memory_init(system_memory,
                       kernel_filename, kernel_cmdline, initrd_filename,
                       below_4g_mem_size, above_4g_mem_size,
                       rom_memory, &ram_memory);
    }

    gsi_state = g_malloc0(sizeof(*gsi_state));
    if (kvm_irqchip_in_kernel()) {
        kvm_pc_setup_irq_routing(pci_enabled);
        gsi = qemu_allocate_irqs(kvm_pc_gsi_handler, gsi_state,
                                 GSI_NUM_PINS);
    } else {
        gsi = qemu_allocate_irqs(gsi_handler, gsi_state, GSI_NUM_PINS);
    }

    if (pci_enabled) {
        pci_bus = i440fx_init(&i440fx_state, &piix3_devfn, &isa_bus, gsi,
                              system_memory, system_io, ram_size,
                              below_4g_mem_size,
                              0x100000000ULL - below_4g_mem_size,
                              0x100000000ULL + above_4g_mem_size,
                              (sizeof(hwaddr) == 4
                               ? 0
                               : ((uint64_t)1 << 62)),
                              pci_memory, ram_memory);
    } else {
        pci_bus = NULL;
        i440fx_state = NULL;
        isa_bus = isa_bus_new(NULL, system_io);
        no_hpet = 1;
    }
    isa_bus_irqs(isa_bus, gsi);

    if (kvm_irqchip_in_kernel()) {
        i8259 = kvm_i8259_init(isa_bus);
    } else if (xen_enabled()) {
        i8259 = xen_interrupt_controller_init();
    } else {
        cpu_irq = pc_allocate_cpu_irq();
        i8259 = i8259_init(isa_bus, cpu_irq[0]);
    }

    for (i = 0; i < ISA_NUM_IRQS; i++) {
        gsi_state->i8259_irq[i] = i8259[i];
    }
    if (pci_enabled) {
        ioapic_init_gsi(gsi_state, "i440fx");
    }
    qdev_init_nofail(icc_bridge);

    pc_register_ferr_irq(gsi[13]);

    pc_vga_init(isa_bus, pci_enabled ? pci_bus : NULL);
    if (xen_enabled()) {
        pci_create_simple(pci_bus, -1, "xen-platform");
    }

    /* init basic PC hardware */
    pc_basic_device_init(isa_bus, gsi, &rtc_state, &floppy, xen_enabled());

    pc_nic_init(isa_bus, pci_bus);

    ide_drive_get(hd, MAX_IDE_BUS);
    if (pci_enabled) {
        PCIDevice *dev;
        if (xen_enabled()) {
            dev = pci_piix3_xen_ide_init(pci_bus, hd, piix3_devfn + 1);
        } else {
            dev = pci_piix3_ide_init(pci_bus, hd, piix3_devfn + 1);
        }
        idebus[0] = qdev_get_child_bus(&dev->qdev, "ide.0");
        idebus[1] = qdev_get_child_bus(&dev->qdev, "ide.1");
    } else {
        for(i = 0; i < MAX_IDE_BUS; i++) {
            ISADevice *dev;
            dev = isa_ide_init(isa_bus, ide_iobase[i], ide_iobase2[i],
                               ide_irq[i],
                               hd[MAX_IDE_DEVS * i], hd[MAX_IDE_DEVS * i + 1]);
            idebus[i] = qdev_get_child_bus(&dev->qdev, "ide.0");
        }
    }

    pc_cmos_init(below_4g_mem_size, above_4g_mem_size, boot_device,
                 floppy, idebus[0], idebus[1], rtc_state);

    if (pci_enabled && usb_enabled(false)) {
        pci_create_simple(pci_bus, piix3_devfn + 2, "piix3-usb-uhci");
    }

    if (pci_enabled && acpi_enabled) {
        i2c_bus *smbus;

        smi_irq = qemu_allocate_irqs(pc_acpi_smi_interrupt,
                                     x86_env_get_cpu(first_cpu), 1);
        /* TODO: Populate SPD eeprom data.  */
        smbus = piix4_pm_init(pci_bus, piix3_devfn + 3, 0xb100,
                              gsi[9], *smi_irq,
                              kvm_enabled(), fw_cfg);
        smbus_eeprom_init(smbus, 8, NULL, 0);
    }

    if (pci_enabled) {
        pc_pci_device_init(pci_bus);
    }

    if (has_pvpanic) {
        pvpanic_init(isa_bus);
    }
}

kvmのvCPUスレッドがどのように作成されているかに注意してください.
pc_init1
->pc_cpus_init
->pc_new_cpu
->cpu_x86_create
->cpu = X86_CPU(object_new(TYPE_X86_CPU));//QOMの使い方を理解する必要がある
->x86_cpu_common_class_init
->dc->realize = x86_cpu_realizefn;
->x86_cpu_realizefn
->qemu_init_vcpu
->qemu_kvm_start_vcpu
->qemu_thread_create(cpu->thread, qemu_kvm_cpu_thread_fn, env, QEMU_THREAD_JOINABLE);->qemu_kvm_cpu_thread_fn
vCPUスレッド:

static void *qemu_kvm_cpu_thread_fn(void *arg)
{
    CPUArchState *env = arg;
    CPUState *cpu = ENV_GET_CPU(env);
    int r;

    qemu_mutex_lock(&qemu_global_mutex);
    qemu_thread_get_self(cpu->thread);
    cpu->thread_id = qemu_get_thread_id();
    cpu_single_env = env;

    r = kvm_init_vcpu(cpu);
    if (r < 0) {
        fprintf(stderr, "kvm_init_vcpu failed: %s
", strerror(-r));
        exit(1);
    }

    qemu_kvm_init_cpu_signals(env);

    /* signal CPU creation */
    cpu->created = true;
    qemu_cond_signal(&qemu_cpu_cond);

    while (1) {
        if (cpu_can_run(cpu)) {
            r = kvm_cpu_exec(env);
            if (r == EXCP_DEBUG) {
                cpu_handle_guest_debug(env);
            }
        }
        qemu_kvm_wait_io_event(env);
    }

    return NULL;
}

kvm_run,割り込み注入(in kvm_arch_pre_run),PMIO,MMIOの処理:

int kvm_cpu_exec(CPUArchState *env)
{
    CPUState *cpu = ENV_GET_CPU(env);
    struct kvm_run *run = cpu->kvm_run;
    int ret, run_ret;

    DPRINTF("kvm_cpu_exec()
");

    if (kvm_arch_process_async_events(cpu)) {
        cpu->exit_request = 0;
        return EXCP_HLT;
    }

    do {
        if (cpu->kvm_vcpu_dirty) {
            kvm_arch_put_registers(cpu, KVM_PUT_RUNTIME_STATE);
            cpu->kvm_vcpu_dirty = false;
        }

        kvm_arch_pre_run(cpu, run);
        if (cpu->exit_request) {
            DPRINTF("interrupt exit requested
");
            /*
             * KVM requires us to reenter the kernel after IO exits to complete
             * instruction emulation. This self-signal will ensure that we
             * leave ASAP again.
             */
            qemu_cpu_kick_self();
        }
        qemu_mutex_unlock_iothread();

        run_ret = kvm_vcpu_ioctl(cpu, KVM_RUN, 0);

        qemu_mutex_lock_iothread();
        kvm_arch_post_run(cpu, run);

        if (run_ret < 0) {
            if (run_ret == -EINTR || run_ret == -EAGAIN) {
                DPRINTF("io window exit
");
                ret = EXCP_INTERRUPT;
                break;
            }
            fprintf(stderr, "error: kvm run failed %s
",
                    strerror(-run_ret));
            abort();
        }

        trace_kvm_run_exit(cpu->cpu_index, run->exit_reason);
        switch (run->exit_reason) {
        case KVM_EXIT_IO:
            DPRINTF("handle_io
");
            kvm_handle_io(run->io.port,
                          (uint8_t *)run + run->io.data_offset,
                          run->io.direction,
                          run->io.size,
                          run->io.count);
            ret = 0;
            break;
        case KVM_EXIT_MMIO:
            DPRINTF("handle_mmio
");
            cpu_physical_memory_rw(run->mmio.phys_addr,
                                   run->mmio.data,
                                   run->mmio.len,
                                   run->mmio.is_write);
            ret = 0;
            break;
        case KVM_EXIT_IRQ_WINDOW_OPEN:
            DPRINTF("irq_window_open
");
            ret = EXCP_INTERRUPT;
            break;
        case KVM_EXIT_SHUTDOWN:
            DPRINTF("shutdown
");
            qemu_system_reset_request();
            ret = EXCP_INTERRUPT;
            break;
        case KVM_EXIT_UNKNOWN:
            fprintf(stderr, "KVM: unknown exit, hardware reason %" PRIx64 "
",
                    (uint64_t)run->hw.hardware_exit_reason);
            ret = -1;
            break;
        case KVM_EXIT_INTERNAL_ERROR:
            ret = kvm_handle_internal_error(env, run);
            break;
        default:
            DPRINTF("kvm_arch_handle_exit
");
            ret = kvm_arch_handle_exit(cpu, run);
            break;
        }
    } while (ret == 0);

    if (ret < 0) {
        cpu_dump_state(env, stderr, fprintf, CPU_DUMP_CODE);
        vm_stop(RUN_STATE_INTERNAL_ERROR);
    }

    cpu->exit_request = 0;
    return ret;
}

qemu_run_machine_init_done_notifiers();
初期化が完了しましたので、チェーンテーブルに登録されている関数をお知らせします

static void qemu_run_machine_init_done_notifiers(void)
{
    notifier_list_notify(&machine_init_done_notifiers, NULL);
}

main_loop();
vmプロセスメインサイクル

static void main_loop(void)
{
    bool nonblocking;
    int last_io = 0;
#ifdef CONFIG_PROFILER
    int64_t ti;
#endif
    do {
        nonblocking = !kvm_enabled() && !xen_enabled() && last_io > 0;
#ifdef CONFIG_PROFILER
        ti = profile_getclock();
#endif
        last_io = main_loop_wait(nonblocking);
#ifdef CONFIG_PROFILER
        dev_time += profile_getclock() - ti;
#endif
    } while (!main_loop_should_exit());
}

PHPで正規表現を扱う際の基本的な3つのポイント

environs