Archipelago » qemu

/*

 * QEMU System Emulator

 *

 * Copyright (c) 2003-2008 Fabrice Bellard

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include <unistd.h>

#include <fcntl.h>

#include <signal.h>

#include <time.h>

#include <errno.h>

#include <sys/time.h>

#include <zlib.h>

/* Needed early for HOST_BSD etc. */

#include "config-host.h"

#ifndef _WIN32

#include <libgen.h>

#include <pwd.h>

#include <sys/times.h>

#include <sys/wait.h>

#include <termios.h>

#include <sys/mman.h>

#include <sys/ioctl.h>

#include <sys/resource.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <net/if.h>

#if defined(__NetBSD__)

#include <net/if_tap.h>

#endif

#ifdef __linux__

#include <linux/if_tun.h>

#endif

#include <arpa/inet.h>

#include <dirent.h>

#include <netdb.h>

#include <sys/select.h>

#ifdef HOST_BSD

#include <sys/stat.h>

#if defined(__FreeBSD__) || defined(__DragonFly__)

#include <libutil.h>

#else

#include <util.h>

#endif

#elif defined (__GLIBC__) && defined (__FreeBSD_kernel__)

#include <freebsd/stdlib.h>

#else

#ifdef __linux__

#include <pty.h>

#include <malloc.h>

#include <linux/rtc.h>

/* For the benefit of older linux systems which don't supply it,

   we use a local copy of hpet.h. */

/* #include <linux/hpet.h> */

#include "hpet.h"

#include <linux/ppdev.h>

#include <linux/parport.h>

#endif

#ifdef __sun__

#include <sys/stat.h>

#include <sys/ethernet.h>

#include <sys/sockio.h>

#include <netinet/arp.h>

#include <netinet/in.h>

#include <netinet/in_systm.h>

#include <netinet/ip.h>

#include <netinet/ip_icmp.h> // must come after ip.h

#include <netinet/udp.h>

#include <netinet/tcp.h>

#include <net/if.h>

#include <syslog.h>

#include <stropts.h>

#endif

#endif

#endif

#if defined(__OpenBSD__)

#include <util.h>

#endif

#if defined(CONFIG_VDE)

#include <libvdeplug.h>

#endif

#ifdef _WIN32

#include <windows.h>

#include <malloc.h>

#include <sys/timeb.h>

#include <mmsystem.h>

#define getopt_long_only getopt_long

#define memalign(align, size) malloc(size)

#endif

#ifdef CONFIG_SDL

#if defined(__APPLE__) || defined(main)

#include <SDL.h>

int qemu_main(int argc, char **argv, char **envp);

int main(int argc, char **argv)

{

    return qemu_main(argc, argv, NULL);

}

#undef main

#define main qemu_main

#endif

#endif /* CONFIG_SDL */

#ifdef CONFIG_COCOA

#undef main

#define main qemu_main

#endif /* CONFIG_COCOA */

#include "hw/hw.h"

#include "hw/boards.h"

#include "hw/usb.h"

#include "hw/pcmcia.h"

#include "hw/pc.h"

#include "hw/audiodev.h"

#include "hw/isa.h"

#include "hw/baum.h"

#include "hw/bt.h"

#include "hw/watchdog.h"

#include "hw/smbios.h"

#include "hw/xen.h"

#include "bt-host.h"

#include "net.h"

#include "monitor.h"

#include "console.h"

#include "sysemu.h"

#include "gdbstub.h"

#include "qemu-timer.h"

#include "qemu-char.h"

#include "cache-utils.h"

#include "block.h"

#include "dma.h"

#include "audio/audio.h"

#include "migration.h"

#include "kvm.h"

#include "balloon.h"

#include "qemu-option.h"

#include "disas.h"

#include "exec-all.h"

#include "qemu_socket.h"

#include "slirp/libslirp.h"

//#define DEBUG_UNUSED_IOPORT

//#define DEBUG_IOPORT

//#define DEBUG_NET

//#define DEBUG_SLIRP

#ifdef DEBUG_IOPORT

#  define LOG_IOPORT(...) qemu_log_mask(CPU_LOG_IOPORT, ## __VA_ARGS__)

#else

#  define LOG_IOPORT(...) do { } while (0)

#endif

#define DEFAULT_RAM_SIZE 128

/* Max number of USB devices that can be specified on the commandline.  */

#define MAX_USB_CMDLINE 8

/* Max number of bluetooth switches on the commandline.  */

#define MAX_BT_CMDLINE 10

/* XXX: use a two level table to limit memory usage */

#define MAX_IOPORTS 65536

static const char *data_dir;

const char *bios_name = NULL;

static void *ioport_opaque[MAX_IOPORTS];

static IOPortReadFunc *ioport_read_table[3][MAX_IOPORTS];

static IOPortWriteFunc *ioport_write_table[3][MAX_IOPORTS];

/* Note: drives_table[MAX_DRIVES] is a dummy block driver if none available

   to store the VM snapshots */

DriveInfo drives_table[MAX_DRIVES+1];

int nb_drives;

enum vga_retrace_method vga_retrace_method = VGA_RETRACE_DUMB;

static DisplayState *display_state;

DisplayType display_type = DT_DEFAULT;

const char* keyboard_layout = NULL;

int64_t ticks_per_sec;

ram_addr_t ram_size;

int nb_nics;

NICInfo nd_table[MAX_NICS];

int vm_running;

static int autostart;

static int rtc_utc = 1;

static int rtc_date_offset = -1; /* -1 means no change */

int cirrus_vga_enabled = 1;

int std_vga_enabled = 0;

int vmsvga_enabled = 0;

int xenfb_enabled = 0;

#ifdef TARGET_SPARC

int graphic_width = 1024;

int graphic_height = 768;

int graphic_depth = 8;

#else

int graphic_width = 800;

int graphic_height = 600;

int graphic_depth = 15;

#endif

static int full_screen = 0;

#ifdef CONFIG_SDL

static int no_frame = 0;

#endif

int no_quit = 0;

CharDriverState *serial_hds[MAX_SERIAL_PORTS];

CharDriverState *parallel_hds[MAX_PARALLEL_PORTS];

CharDriverState *virtcon_hds[MAX_VIRTIO_CONSOLES];

#ifdef TARGET_I386

int win2k_install_hack = 0;

int rtc_td_hack = 0;

#endif

int usb_enabled = 0;

int singlestep = 0;

int smp_cpus = 1;

const char *vnc_display;

int acpi_enabled = 1;

int no_hpet = 0;

int no_virtio_balloon = 0;

int fd_bootchk = 1;

int no_reboot = 0;

int no_shutdown = 0;

int cursor_hide = 1;

int graphic_rotate = 0;

#ifndef _WIN32

int daemonize = 0;

#endif

WatchdogTimerModel *watchdog = NULL;

int watchdog_action = WDT_RESET;

const char *option_rom[MAX_OPTION_ROMS];

int nb_option_roms;

int semihosting_enabled = 0;

#ifdef TARGET_ARM

int old_param = 0;

#endif

const char *qemu_name;

int alt_grab = 0;

#if defined(TARGET_SPARC) || defined(TARGET_PPC)

unsigned int nb_prom_envs = 0;

const char *prom_envs[MAX_PROM_ENVS];

#endif

int nb_drives_opt;

struct drive_opt drives_opt[MAX_DRIVES];

int nb_numa_nodes;

uint64_t node_mem[MAX_NODES];

uint64_t node_cpumask[MAX_NODES];

static CPUState *cur_cpu;

static CPUState *next_cpu;

static int timer_alarm_pending = 1;

/* Conversion factor from emulated instructions to virtual clock ticks.  */

static int icount_time_shift;

/* Arbitrarily pick 1MIPS as the minimum allowable speed.  */

#define MAX_ICOUNT_SHIFT 10

/* Compensate for varying guest execution speed.  */

static int64_t qemu_icount_bias;

static QEMUTimer *icount_rt_timer;

static QEMUTimer *icount_vm_timer;

static QEMUTimer *nographic_timer;

uint8_t qemu_uuid[16];

/***********************************************************/

/* x86 ISA bus support */

target_phys_addr_t isa_mem_base = 0;

PicState2 *isa_pic;

static IOPortReadFunc default_ioport_readb, default_ioport_readw, default_ioport_readl;

static IOPortWriteFunc default_ioport_writeb, default_ioport_writew, default_ioport_writel;

static uint32_t ioport_read(int index, uint32_t address)

{

    static IOPortReadFunc *default_func[3] = {

        default_ioport_readb,

        default_ioport_readw,

        default_ioport_readl

    };

    IOPortReadFunc *func = ioport_read_table[index][address];

    if (!func)

        func = default_func[index];

    return func(ioport_opaque[address], address);

}

static void ioport_write(int index, uint32_t address, uint32_t data)

{

    static IOPortWriteFunc *default_func[3] = {

        default_ioport_writeb,

        default_ioport_writew,

        default_ioport_writel

    };

    IOPortWriteFunc *func = ioport_write_table[index][address];

    if (!func)

        func = default_func[index];

    func(ioport_opaque[address], address, data);

}

static uint32_t default_ioport_readb(void *opaque, uint32_t address)

{

#ifdef DEBUG_UNUSED_IOPORT

    fprintf(stderr, "unused inb: port=0x%04x\n", address);

#endif

    return 0xff;

}

static void default_ioport_writeb(void *opaque, uint32_t address, uint32_t data)

{

#ifdef DEBUG_UNUSED_IOPORT

    fprintf(stderr, "unused outb: port=0x%04x data=0x%02x\n", address, data);

#endif

}

/* default is to make two byte accesses */

static uint32_t default_ioport_readw(void *opaque, uint32_t address)

{

    uint32_t data;

    data = ioport_read(0, address);

    address = (address + 1) & (MAX_IOPORTS - 1);

    data |= ioport_read(0, address) << 8;

    return data;

}

static void default_ioport_writew(void *opaque, uint32_t address, uint32_t data)

{

    ioport_write(0, address, data & 0xff);

    address = (address + 1) & (MAX_IOPORTS - 1);

    ioport_write(0, address, (data >> 8) & 0xff);

}

static uint32_t default_ioport_readl(void *opaque, uint32_t address)

{

#ifdef DEBUG_UNUSED_IOPORT

    fprintf(stderr, "unused inl: port=0x%04x\n", address);

#endif

    return 0xffffffff;

}

static void default_ioport_writel(void *opaque, uint32_t address, uint32_t data)

{

#ifdef DEBUG_UNUSED_IOPORT

    fprintf(stderr, "unused outl: port=0x%04x data=0x%02x\n", address, data);

#endif

}

/* size is the word size in byte */

int register_ioport_read(int start, int length, int size,

                         IOPortReadFunc *func, void *opaque)

{

    int i, bsize;

    if (size == 1) {

        bsize = 0;

    } else if (size == 2) {

        bsize = 1;

    } else if (size == 4) {

        bsize = 2;

    } else {

        hw_error("register_ioport_read: invalid size");

        return -1;

    }

    for(i = start; i < start + length; i += size) {

        ioport_read_table[bsize][i] = func;

        if (ioport_opaque[i] != NULL && ioport_opaque[i] != opaque)

            hw_error("register_ioport_read: invalid opaque");

        ioport_opaque[i] = opaque;

    }

    return 0;

}

/* size is the word size in byte */

int register_ioport_write(int start, int length, int size,

                          IOPortWriteFunc *func, void *opaque)

{

    int i, bsize;

    if (size == 1) {

        bsize = 0;

    } else if (size == 2) {

        bsize = 1;

    } else if (size == 4) {

        bsize = 2;

    } else {

        hw_error("register_ioport_write: invalid size");

        return -1;

    }

    for(i = start; i < start + length; i += size) {

        ioport_write_table[bsize][i] = func;

        if (ioport_opaque[i] != NULL && ioport_opaque[i] != opaque)

            hw_error("register_ioport_write: invalid opaque");

        ioport_opaque[i] = opaque;

    }

    return 0;

}

void isa_unassign_ioport(int start, int length)

{

    int i;

    for(i = start; i < start + length; i++) {

        ioport_read_table[0][i] = default_ioport_readb;

        ioport_read_table[1][i] = default_ioport_readw;

        ioport_read_table[2][i] = default_ioport_readl;

        ioport_write_table[0][i] = default_ioport_writeb;

        ioport_write_table[1][i] = default_ioport_writew;

        ioport_write_table[2][i] = default_ioport_writel;

        ioport_opaque[i] = NULL;

    }

}

/***********************************************************/

void cpu_outb(CPUState *env, int addr, int val)

{

    LOG_IOPORT("outb: %04x %02x\n", addr, val);

    ioport_write(0, addr, val);

#ifdef CONFIG_KQEMU

    if (env)

        env->last_io_time = cpu_get_time_fast();

#endif

}

void cpu_outw(CPUState *env, int addr, int val)

{

    LOG_IOPORT("outw: %04x %04x\n", addr, val);

    ioport_write(1, addr, val);

#ifdef CONFIG_KQEMU

    if (env)

        env->last_io_time = cpu_get_time_fast();

#endif

}

void cpu_outl(CPUState *env, int addr, int val)

{

    LOG_IOPORT("outl: %04x %08x\n", addr, val);

    ioport_write(2, addr, val);

#ifdef CONFIG_KQEMU

    if (env)

        env->last_io_time = cpu_get_time_fast();

#endif

}

int cpu_inb(CPUState *env, int addr)

{

    int val;

    val = ioport_read(0, addr);

    LOG_IOPORT("inb : %04x %02x\n", addr, val);

#ifdef CONFIG_KQEMU

    if (env)

        env->last_io_time = cpu_get_time_fast();

#endif

    return val;

}

int cpu_inw(CPUState *env, int addr)

{

    int val;

    val = ioport_read(1, addr);

    LOG_IOPORT("inw : %04x %04x\n", addr, val);

#ifdef CONFIG_KQEMU

    if (env)

        env->last_io_time = cpu_get_time_fast();

#endif

    return val;

}

int cpu_inl(CPUState *env, int addr)

{

    int val;

    val = ioport_read(2, addr);

    LOG_IOPORT("inl : %04x %08x\n", addr, val);

#ifdef CONFIG_KQEMU

    if (env)

        env->last_io_time = cpu_get_time_fast();

#endif

    return val;

}

/***********************************************************/

void hw_error(const char *fmt, ...)

{

    va_list ap;

    CPUState *env;

    va_start(ap, fmt);

    fprintf(stderr, "qemu: hardware error: ");

    vfprintf(stderr, fmt, ap);

    fprintf(stderr, "\n");

    for(env = first_cpu; env != NULL; env = env->next_cpu) {

        fprintf(stderr, "CPU #%d:\n", env->cpu_index);

#ifdef TARGET_I386

        cpu_dump_state(env, stderr, fprintf, X86_DUMP_FPU);

#else

        cpu_dump_state(env, stderr, fprintf, 0);

#endif

    }

    va_end(ap);

    abort();

}

/***************/

/* ballooning */

static QEMUBalloonEvent *qemu_balloon_event;

void *qemu_balloon_event_opaque;

void qemu_add_balloon_handler(QEMUBalloonEvent *func, void *opaque)

{

    qemu_balloon_event = func;

    qemu_balloon_event_opaque = opaque;

}

void qemu_balloon(ram_addr_t target)

{

    if (qemu_balloon_event)

        qemu_balloon_event(qemu_balloon_event_opaque, target);

}

ram_addr_t qemu_balloon_status(void)

{

    if (qemu_balloon_event)

        return qemu_balloon_event(qemu_balloon_event_opaque, 0);

    return 0;

}

/***********************************************************/

/* keyboard/mouse */

static QEMUPutKBDEvent *qemu_put_kbd_event;

static void *qemu_put_kbd_event_opaque;

static QEMUPutMouseEntry *qemu_put_mouse_event_head;

static QEMUPutMouseEntry *qemu_put_mouse_event_current;

void qemu_add_kbd_event_handler(QEMUPutKBDEvent *func, void *opaque)

{

    qemu_put_kbd_event_opaque = opaque;

    qemu_put_kbd_event = func;

}

QEMUPutMouseEntry *qemu_add_mouse_event_handler(QEMUPutMouseEvent *func,

                                                void *opaque, int absolute,

                                                const char *name)

{

    QEMUPutMouseEntry *s, *cursor;

    s = qemu_mallocz(sizeof(QEMUPutMouseEntry));

    s->qemu_put_mouse_event = func;

    s->qemu_put_mouse_event_opaque = opaque;

    s->qemu_put_mouse_event_absolute = absolute;

    s->qemu_put_mouse_event_name = qemu_strdup(name);

    s->next = NULL;

    if (!qemu_put_mouse_event_head) {

        qemu_put_mouse_event_head = qemu_put_mouse_event_current = s;

        return s;

    }

    cursor = qemu_put_mouse_event_head;

    while (cursor->next != NULL)

        cursor = cursor->next;

    cursor->next = s;

    qemu_put_mouse_event_current = s;

    return s;

}

void qemu_remove_mouse_event_handler(QEMUPutMouseEntry *entry)

{

    QEMUPutMouseEntry *prev = NULL, *cursor;

    if (!qemu_put_mouse_event_head || entry == NULL)

        return;

    cursor = qemu_put_mouse_event_head;

    while (cursor != NULL && cursor != entry) {

        prev = cursor;

        cursor = cursor->next;

    }

    if (cursor == NULL) // does not exist or list empty

        return;

    else if (prev == NULL) { // entry is head

        qemu_put_mouse_event_head = cursor->next;

        if (qemu_put_mouse_event_current == entry)

            qemu_put_mouse_event_current = cursor->next;

        qemu_free(entry->qemu_put_mouse_event_name);

        qemu_free(entry);

        return;

    }

    prev->next = entry->next;

    if (qemu_put_mouse_event_current == entry)

        qemu_put_mouse_event_current = prev;

    qemu_free(entry->qemu_put_mouse_event_name);

    qemu_free(entry);

}

void kbd_put_keycode(int keycode)

{

    if (qemu_put_kbd_event) {

        qemu_put_kbd_event(qemu_put_kbd_event_opaque, keycode);

    }

}

void kbd_mouse_event(int dx, int dy, int dz, int buttons_state)

{

    QEMUPutMouseEvent *mouse_event;

    void *mouse_event_opaque;

    int width;

    if (!qemu_put_mouse_event_current) {

        return;

    }

    mouse_event =

        qemu_put_mouse_event_current->qemu_put_mouse_event;

    mouse_event_opaque =

        qemu_put_mouse_event_current->qemu_put_mouse_event_opaque;

    if (mouse_event) {

        if (graphic_rotate) {

            if (qemu_put_mouse_event_current->qemu_put_mouse_event_absolute)

                width = 0x7fff;

            else

                width = graphic_width - 1;

            mouse_event(mouse_event_opaque,

                                 width - dy, dx, dz, buttons_state);

        } else

            mouse_event(mouse_event_opaque,

                                 dx, dy, dz, buttons_state);

    }

}

int kbd_mouse_is_absolute(void)

{

    if (!qemu_put_mouse_event_current)

        return 0;

    return qemu_put_mouse_event_current->qemu_put_mouse_event_absolute;

}

void do_info_mice(Monitor *mon)

{

    QEMUPutMouseEntry *cursor;

    int index = 0;

    if (!qemu_put_mouse_event_head) {

        monitor_printf(mon, "No mouse devices connected\n");

        return;

    }

    monitor_printf(mon, "Mouse devices available:\n");

    cursor = qemu_put_mouse_event_head;

    while (cursor != NULL) {

        monitor_printf(mon, "%c Mouse #%d: %s\n",

                       (cursor == qemu_put_mouse_event_current ? '*' : ' '),

                       index, cursor->qemu_put_mouse_event_name);

        index++;

        cursor = cursor->next;

    }

}

void do_mouse_set(Monitor *mon, int index)

{

    QEMUPutMouseEntry *cursor;

    int i = 0;

    if (!qemu_put_mouse_event_head) {

        monitor_printf(mon, "No mouse devices connected\n");

        return;

    }

    cursor = qemu_put_mouse_event_head;

    while (cursor != NULL && index != i) {

        i++;

        cursor = cursor->next;

    }

    if (cursor != NULL)

        qemu_put_mouse_event_current = cursor;

    else

        monitor_printf(mon, "Mouse at given index not found\n");

}

/* compute with 96 bit intermediate result: (a*b)/c */

uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c)

{

    union {

        uint64_t ll;

        struct {

#ifdef WORDS_BIGENDIAN

            uint32_t high, low;

#else

            uint32_t low, high;

#endif

        } l;

    } u, res;

    uint64_t rl, rh;

    u.ll = a;

    rl = (uint64_t)u.l.low * (uint64_t)b;

    rh = (uint64_t)u.l.high * (uint64_t)b;

    rh += (rl >> 32);

    res.l.high = rh / c;

    res.l.low = (((rh % c) << 32) + (rl & 0xffffffff)) / c;

    return res.ll;

}

/***********************************************************/

/* real time host monotonic timer */

#define QEMU_TIMER_BASE 1000000000LL

#ifdef WIN32

static int64_t clock_freq;

static void init_get_clock(void)

{

    LARGE_INTEGER freq;

    int ret;

    ret = QueryPerformanceFrequency(&freq);

    if (ret == 0) {

        fprintf(stderr, "Could not calibrate ticks\n");

        exit(1);

    }

    clock_freq = freq.QuadPart;

}

static int64_t get_clock(void)

{

    LARGE_INTEGER ti;

    QueryPerformanceCounter(&ti);

    return muldiv64(ti.QuadPart, QEMU_TIMER_BASE, clock_freq);

}

#else

static int use_rt_clock;

static void init_get_clock(void)

{

    use_rt_clock = 0;

#if defined(__linux__) || (defined(__FreeBSD__) && __FreeBSD_version >= 500000) \

    || defined(__DragonFly__)

    {

        struct timespec ts;

        if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0) {

            use_rt_clock = 1;

        }

    }

#endif

}

static int64_t get_clock(void)

{

#if defined(__linux__) || (defined(__FreeBSD__) && __FreeBSD_version >= 500000) \

        || defined(__DragonFly__)

    if (use_rt_clock) {

        struct timespec ts;

        clock_gettime(CLOCK_MONOTONIC, &ts);

        return ts.tv_sec * 1000000000LL + ts.tv_nsec;

    } else

#endif

    {

        /* XXX: using gettimeofday leads to problems if the date

           changes, so it should be avoided. */

        struct timeval tv;

        gettimeofday(&tv, NULL);

        return tv.tv_sec * 1000000000LL + (tv.tv_usec * 1000);

    }

}

#endif

/* Return the virtual CPU time, based on the instruction counter.  */

static int64_t cpu_get_icount(void)

{

    int64_t icount;

    CPUState *env = cpu_single_env;;

    icount = qemu_icount;

    if (env) {

        if (!can_do_io(env))

            fprintf(stderr, "Bad clock read\n");

        icount -= (env->icount_decr.u16.low + env->icount_extra);

    }

    return qemu_icount_bias + (icount << icount_time_shift);

}

/***********************************************************/

/* guest cycle counter */

static int64_t cpu_ticks_prev;

static int64_t cpu_ticks_offset;

static int64_t cpu_clock_offset;

static int cpu_ticks_enabled;

/* return the host CPU cycle counter and handle stop/restart */

int64_t cpu_get_ticks(void)

{

    if (use_icount) {

        return cpu_get_icount();

    }

    if (!cpu_ticks_enabled) {

        return cpu_ticks_offset;

    } else {

        int64_t ticks;

        ticks = cpu_get_real_ticks();

        if (cpu_ticks_prev > ticks) {

            /* Note: non increasing ticks may happen if the host uses

               software suspend */

            cpu_ticks_offset += cpu_ticks_prev - ticks;

        }

        cpu_ticks_prev = ticks;

        return ticks + cpu_ticks_offset;

    }

}

/* return the host CPU monotonic timer and handle stop/restart */

static int64_t cpu_get_clock(void)

{

    int64_t ti;

    if (!cpu_ticks_enabled) {

        return cpu_clock_offset;

    } else {

        ti = get_clock();

        return ti + cpu_clock_offset;

    }

}

/* enable cpu_get_ticks() */

void cpu_enable_ticks(void)

{

    if (!cpu_ticks_enabled) {

        cpu_ticks_offset -= cpu_get_real_ticks();

        cpu_clock_offset -= get_clock();

        cpu_ticks_enabled = 1;

    }

}

/* disable cpu_get_ticks() : the clock is stopped. You must not call

   cpu_get_ticks() after that.  */

void cpu_disable_ticks(void)

{

    if (cpu_ticks_enabled) {

        cpu_ticks_offset = cpu_get_ticks();

        cpu_clock_offset = cpu_get_clock();

        cpu_ticks_enabled = 0;

    }

}

/***********************************************************/

/* timers */

#define QEMU_TIMER_REALTIME 0

#define QEMU_TIMER_VIRTUAL  1

struct QEMUClock {

    int type;

    /* XXX: add frequency */

};

struct QEMUTimer {

    QEMUClock *clock;

    int64_t expire_time;

    QEMUTimerCB *cb;

    void *opaque;

    struct QEMUTimer *next;

};

struct qemu_alarm_timer {

    char const *name;

    unsigned int flags;

    int (*start)(struct qemu_alarm_timer *t);

    void (*stop)(struct qemu_alarm_timer *t);

    void (*rearm)(struct qemu_alarm_timer *t);

    void *priv;

};

#define ALARM_FLAG_DYNTICKS  0x1

#define ALARM_FLAG_EXPIRED   0x2

static inline int alarm_has_dynticks(struct qemu_alarm_timer *t)

{

    return t && (t->flags & ALARM_FLAG_DYNTICKS);

}

static void qemu_rearm_alarm_timer(struct qemu_alarm_timer *t)

{

    if (!alarm_has_dynticks(t))

        return;

    t->rearm(t);

}

/* TODO: MIN_TIMER_REARM_US should be optimized */

#define MIN_TIMER_REARM_US 250

static struct qemu_alarm_timer *alarm_timer;

#ifdef _WIN32

struct qemu_alarm_win32 {

    MMRESULT timerId;

    unsigned int period;

} alarm_win32_data = {0, -1};

static int win32_start_timer(struct qemu_alarm_timer *t);

static void win32_stop_timer(struct qemu_alarm_timer *t);

static void win32_rearm_timer(struct qemu_alarm_timer *t);

#else

static int unix_start_timer(struct qemu_alarm_timer *t);

static void unix_stop_timer(struct qemu_alarm_timer *t);

#ifdef __linux__

static int dynticks_start_timer(struct qemu_alarm_timer *t);

static void dynticks_stop_timer(struct qemu_alarm_timer *t);

static void dynticks_rearm_timer(struct qemu_alarm_timer *t);

static int hpet_start_timer(struct qemu_alarm_timer *t);

static void hpet_stop_timer(struct qemu_alarm_timer *t);

static int rtc_start_timer(struct qemu_alarm_timer *t);

static void rtc_stop_timer(struct qemu_alarm_timer *t);

#endif /* __linux__ */

#endif /* _WIN32 */

/* Correlation between real and virtual time is always going to be

   fairly approximate, so ignore small variation.

   When the guest is idle real and virtual time will be aligned in

   the IO wait loop.  */

#define ICOUNT_WOBBLE (QEMU_TIMER_BASE / 10)

static void icount_adjust(void)

{

    int64_t cur_time;

    int64_t cur_icount;

    int64_t delta;

    static int64_t last_delta;

    /* If the VM is not running, then do nothing.  */

    if (!vm_running)

        return;

    cur_time = cpu_get_clock();

    cur_icount = qemu_get_clock(vm_clock);

    delta = cur_icount - cur_time;

    /* FIXME: This is a very crude algorithm, somewhat prone to oscillation.  */

    if (delta > 0

        && last_delta + ICOUNT_WOBBLE < delta * 2

        && icount_time_shift > 0) {

        /* The guest is getting too far ahead.  Slow time down.  */

        icount_time_shift--;

    }

    if (delta < 0

        && last_delta - ICOUNT_WOBBLE > delta * 2

        && icount_time_shift < MAX_ICOUNT_SHIFT) {

        /* The guest is getting too far behind.  Speed time up.  */

        icount_time_shift++;

    }

    last_delta = delta;

    qemu_icount_bias = cur_icount - (qemu_icount << icount_time_shift);

}

static void icount_adjust_rt(void * opaque)

{

    qemu_mod_timer(icount_rt_timer,

                   qemu_get_clock(rt_clock) + 1000);

    icount_adjust();

}

static void icount_adjust_vm(void * opaque)

{

    qemu_mod_timer(icount_vm_timer,

                   qemu_get_clock(vm_clock) + QEMU_TIMER_BASE / 10);

    icount_adjust();

}

static void init_icount_adjust(void)

{

    /* Have both realtime and virtual time triggers for speed adjustment.

       The realtime trigger catches emulated time passing too slowly,

       the virtual time trigger catches emulated time passing too fast.

       Realtime triggers occur even when idle, so use them less frequently

       than VM triggers.  */

    icount_rt_timer = qemu_new_timer(rt_clock, icount_adjust_rt, NULL);

    qemu_mod_timer(icount_rt_timer,

                   qemu_get_clock(rt_clock) + 1000);

    icount_vm_timer = qemu_new_timer(vm_clock, icount_adjust_vm, NULL);

    qemu_mod_timer(icount_vm_timer,

                   qemu_get_clock(vm_clock) + QEMU_TIMER_BASE / 10);

}

static struct qemu_alarm_timer alarm_timers[] = {

#ifndef _WIN32

#ifdef __linux__

    {"dynticks", ALARM_FLAG_DYNTICKS, dynticks_start_timer,

     dynticks_stop_timer, dynticks_rearm_timer, NULL},

    /* HPET - if available - is preferred */

    {"hpet", 0, hpet_start_timer, hpet_stop_timer, NULL, NULL},

    /* ...otherwise try RTC */

    {"rtc", 0, rtc_start_timer, rtc_stop_timer, NULL, NULL},

#endif

    {"unix", 0, unix_start_timer, unix_stop_timer, NULL, NULL},

#else

    {"dynticks", ALARM_FLAG_DYNTICKS, win32_start_timer,

     win32_stop_timer, win32_rearm_timer, &alarm_win32_data},

    {"win32", 0, win32_start_timer,

     win32_stop_timer, NULL, &alarm_win32_data},

#endif

    {NULL, }

};

static void show_available_alarms(void)

{

    int i;

    printf("Available alarm timers, in order of precedence:\n");

    for (i = 0; alarm_timers[i].name; i++)

        printf("%s\n", alarm_timers[i].name);

}

static void configure_alarms(char const *opt)

{

    int i;

    int cur = 0;

    int count = ARRAY_SIZE(alarm_timers) - 1;

    char *arg;

    char *name;

    struct qemu_alarm_timer tmp;

    if (!strcmp(opt, "?")) {

        show_available_alarms();

        exit(0);

    }

    arg = strdup(opt);

    /* Reorder the array */

    name = strtok(arg, ",");

    while (name) {

        for (i = 0; i < count && alarm_timers[i].name; i++) {

            if (!strcmp(alarm_timers[i].name, name))

                break;

        }

        if (i == count) {

            fprintf(stderr, "Unknown clock %s\n", name);

            goto next;

        }

        if (i < cur)

            /* Ignore */

            goto next;

        /* Swap */

        tmp = alarm_timers[i];

        alarm_timers[i] = alarm_timers[cur];

        alarm_timers[cur] = tmp;

        cur++;

next:

        name = strtok(NULL, ",");

    }

    free(arg);

    if (cur) {

        /* Disable remaining timers */

        for (i = cur; i < count; i++)

            alarm_timers[i].name = NULL;

    } else {

        show_available_alarms();

        exit(1);

    }

}

QEMUClock *rt_clock;

QEMUClock *vm_clock;

static QEMUTimer *active_timers[2];

static QEMUClock *qemu_new_clock(int type)

{

    QEMUClock *clock;

    clock = qemu_mallocz(sizeof(QEMUClock));

    clock->type = type;

    return clock;

}

QEMUTimer *qemu_new_timer(QEMUClock *clock, QEMUTimerCB *cb, void *opaque)

{

    QEMUTimer *ts;

    ts = qemu_mallocz(sizeof(QEMUTimer));

    ts->clock = clock;

    ts->cb = cb;

    ts->opaque = opaque;

    return ts;

}

void qemu_free_timer(QEMUTimer *ts)

{

    qemu_free(ts);

}

/* stop a timer, but do not dealloc it */

void qemu_del_timer(QEMUTimer *ts)

{

    QEMUTimer **pt, *t;

    /* NOTE: this code must be signal safe because

       qemu_timer_expired() can be called from a signal. */

    pt = &active_timers[ts->clock->type];

    for(;;) {

        t = *pt;

        if (!t)

            break;

        if (t == ts) {

            *pt = t->next;

            break;

        }

        pt = &t->next;

    }

}

/* modify the current timer so that it will be fired when current_time

   >= expire_time. The corresponding callback will be called. */

void qemu_mod_timer(QEMUTimer *ts, int64_t expire_time)

{

    QEMUTimer **pt, *t;

    qemu_del_timer(ts);

    /* add the timer in the sorted list */

    /* NOTE: this code must be signal safe because

       qemu_timer_expired() can be called from a signal. */

    pt = &active_timers[ts->clock->type];

    for(;;) {

        t = *pt;

        if (!t)

            break;

        if (t->expire_time > expire_time)

            break;

        pt = &t->next;

    }

    ts->expire_time = expire_time;

    ts->next = *pt;

    *pt = ts;

    /* Rearm if necessary  */

    if (pt == &active_timers[ts->clock->type]) {

        if ((alarm_timer->flags & ALARM_FLAG_EXPIRED) == 0) {

            qemu_rearm_alarm_timer(alarm_timer);

        }

        /* Interrupt execution to force deadline recalculation.  */

        if (use_icount)

            qemu_notify_event();

    }

}

int qemu_timer_pending(QEMUTimer *ts)

{

    QEMUTimer *t;

    for(t = active_timers[ts->clock->type]; t != NULL; t = t->next) {

        if (t == ts)

            return 1;

    }

    return 0;

}

static inline int qemu_timer_expired(QEMUTimer *timer_head, int64_t current_time)

{

    if (!timer_head)

        return 0;

    return (timer_head->expire_time <= current_time);

}

static void qemu_run_timers(QEMUTimer **ptimer_head, int64_t current_time)

{

    QEMUTimer *ts;

    for(;;) {

        ts = *ptimer_head;

        if (!ts || ts->expire_time > current_time)

            break;

        /* remove timer from the list before calling the callback */

        *ptimer_head = ts->next;

        ts->next = NULL;

        /* run the callback (the timer list can be modified) */

        ts->cb(ts->opaque);

    }

}

int64_t qemu_get_clock(QEMUClock *clock)

{

    switch(clock->type) {

    case QEMU_TIMER_REALTIME:

        return get_clock() / 1000000;

    default:

    case QEMU_TIMER_VIRTUAL:

        if (use_icount) {

            return cpu_get_icount();

        } else {

            return cpu_get_clock();

        }

    }

}

static void init_timers(void)

{

    init_get_clock();

    ticks_per_sec = QEMU_TIMER_BASE;

    rt_clock = qemu_new_clock(QEMU_TIMER_REALTIME);

    vm_clock = qemu_new_clock(QEMU_TIMER_VIRTUAL);

}

/* save a timer */

void qemu_put_timer(QEMUFile *f, QEMUTimer *ts)

{

    uint64_t expire_time;

    if (qemu_timer_pending(ts)) {

        expire_time = ts->expire_time;

    } else {

        expire_time = -1;

    }

    qemu_put_be64(f, expire_time);

}

void qemu_get_timer(QEMUFile *f, QEMUTimer *ts)

{

    uint64_t expire_time;

    expire_time = qemu_get_be64(f);

    if (expire_time != -1) {

        qemu_mod_timer(ts, expire_time);

    } else {

        qemu_del_timer(ts);

    }

}

static void timer_save(QEMUFile *f, void *opaque)

{

    if (cpu_ticks_enabled) {

        hw_error("cannot save state if virtual timers are running");

    }

    qemu_put_be64(f, cpu_ticks_offset);

    qemu_put_be64(f, ticks_per_sec);

    qemu_put_be64(f, cpu_clock_offset);

}

static int timer_load(QEMUFile *f, void *opaque, int version_id)

{

    if (version_id != 1 && version_id != 2)

        return -EINVAL;

    if (cpu_ticks_enabled) {

        return -EINVAL;

    }

    cpu_ticks_offset=qemu_get_be64(f);

    ticks_per_sec=qemu_get_be64(f);

    if (version_id == 2) {

        cpu_clock_offset=qemu_get_be64(f);

    }

    return 0;

}

static void qemu_event_increment(void);

#ifdef _WIN32

static void CALLBACK host_alarm_handler(UINT uTimerID, UINT uMsg,

                                        DWORD_PTR dwUser, DWORD_PTR dw1,

                                        DWORD_PTR dw2)

#else

static void host_alarm_handler(int host_signum)

#endif

{

#if 0

#define DISP_FREQ 1000

    {

        static int64_t delta_min = INT64_MAX;

        static int64_t delta_max, delta_cum, last_clock, delta, ti;

        static int count;

        ti = qemu_get_clock(vm_clock);

        if (last_clock != 0) {

            delta = ti - last_clock;

            if (delta < delta_min)

                delta_min = delta;

            if (delta > delta_max)

                delta_max = delta;

            delta_cum += delta;

            if (++count == DISP_FREQ) {

                printf("timer: min=%" PRId64 " us max=%" PRId64 " us avg=%" PRId64 " us avg_freq=%0.3f Hz\n",