monitor.c

/*
 * QEMU monitor
 *
 * Copyright (c) 2003-2004 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 "qemu/osdep.h"
#include "qemu/units.h"
#include <dirent.h>
#include "cpu.h"
#include "hw/hw.h"
#include "monitor/qdev.h"
#include "hw/usb.h"
#include "hw/pci/pci.h"
#include "sysemu/watchdog.h"
#include "hw/loader.h"
#include "exec/gdbstub.h"
#include "net/net.h"
#include "net/slirp.h"
#include "chardev/char-fe.h"
#include "chardev/char-io.h"
#include "chardev/char-mux.h"
#include "ui/qemu-spice.h"
#include "sysemu/numa.h"
#include "monitor/monitor.h"
#include "qemu/config-file.h"
#include "qemu/ctype.h"
#include "qemu/readline.h"
#include "ui/console.h"
#include "ui/input.h"
#include "sysemu/block-backend.h"
#include "audio/audio.h"
#include "disas/disas.h"
#include "sysemu/balloon.h"
#include "qemu/timer.h"
#include "sysemu/hw_accel.h"
#include "authz/list.h"
#include "qapi/util.h"
#include "sysemu/tcg.h"
#include "sysemu/tpm.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qerror.h"
#include "qapi/qmp/qnum.h"
#include "qapi/qmp/qstring.h"
#include "qapi/qmp/qjson.h"
#include "qapi/qmp/json-parser.h"
#include "qapi/qmp/qlist.h"
#include "qom/object_interfaces.h"
#include "trace-root.h"
#include "trace/control.h"
#include "monitor/hmp-target.h"
#ifdef CONFIG_TRACE_SIMPLE
#include "trace/simple.h"
#endif
#include "exec/memory.h"
#include "exec/exec-all.h"
#include "qemu/log.h"
#include "qemu/option.h"
#include "hmp.h"
#include "qemu/thread.h"
#include "block/qapi.h"
#include "qapi/qapi-commands.h"
#include "qapi/qapi-emit-events.h"
#include "qapi/error.h"
#include "qapi/qmp-event.h"
#include "qapi/qapi-introspect.h"
#include "sysemu/qtest.h"
#include "sysemu/cpus.h"
#include "sysemu/iothread.h"
#include "qemu/cutils.h"
#include "tcg/tcg.h"

#if defined(TARGET_S390X)
#include "hw/s390x/storage-keys.h"
#include "hw/s390x/storage-attributes.h"
#endif

/*
 * Supported types:
 *
 * 'F'          filename
 * 'B'          block device name
 * 's'          string (accept optional quote)
 * 'S'          it just appends the rest of the string (accept optional quote)
 * 'O'          option string of the form NAME=VALUE,...
 *              parsed according to QemuOptsList given by its name
 *              Example: 'device:O' uses qemu_device_opts.
 *              Restriction: only lists with empty desc are supported
 *              TODO lift the restriction
 * 'i'          32 bit integer
 * 'l'          target long (32 or 64 bit)
 * 'M'          Non-negative target long (32 or 64 bit), in user mode the
 *              value is multiplied by 2^20 (think Mebibyte)
 * 'o'          octets (aka bytes)
 *              user mode accepts an optional E, e, P, p, T, t, G, g, M, m,
 *              K, k suffix, which multiplies the value by 2^60 for suffixes E
 *              and e, 2^50 for suffixes P and p, 2^40 for suffixes T and t,
 *              2^30 for suffixes G and g, 2^20 for M and m, 2^10 for K and k
 * 'T'          double
 *              user mode accepts an optional ms, us, ns suffix,
 *              which divides the value by 1e3, 1e6, 1e9, respectively
 * '/'          optional gdb-like print format (like "/10x")
 *
 * '?'          optional type (for all types, except '/')
 * '.'          other form of optional type (for 'i' and 'l')
 * 'b'          boolean
 *              user mode accepts "on" or "off"
 * '-'          optional parameter (eg. '-f')
 *
 */

typedef struct mon_cmd_t {
    const char *name;
    const char *args_type;
    const char *params;
    const char *help;
    const char *flags; /* p=preconfig */
    void (*cmd)(Monitor *mon, const QDict *qdict);
    /* @sub_table is a list of 2nd level of commands. If it does not exist,
     * cmd should be used. If it exists, sub_table[?].cmd should be
     * used, and cmd of 1st level plays the role of help function.
     */
    struct mon_cmd_t *sub_table;
    void (*command_completion)(ReadLineState *rs, int nb_args, const char *str);
} mon_cmd_t;

/* file descriptors passed via SCM_RIGHTS */
typedef struct mon_fd_t mon_fd_t;
struct mon_fd_t {
    char *name;
    int fd;
    QLIST_ENTRY(mon_fd_t) next;
};

/* file descriptor associated with a file descriptor set */
typedef struct MonFdsetFd MonFdsetFd;
struct MonFdsetFd {
    int fd;
    bool removed;
    char *opaque;
    QLIST_ENTRY(MonFdsetFd) next;
};

/* file descriptor set containing fds passed via SCM_RIGHTS */
typedef struct MonFdset MonFdset;
struct MonFdset {
    int64_t id;
    QLIST_HEAD(, MonFdsetFd) fds;
    QLIST_HEAD(, MonFdsetFd) dup_fds;
    QLIST_ENTRY(MonFdset) next;
};

/*
 * To prevent flooding clients, events can be throttled. The
 * throttling is calculated globally, rather than per-Monitor
 * instance.
 */
typedef struct MonitorQAPIEventState {
    QAPIEvent event;    /* Throttling state for this event type and... */
    QDict *data;        /* ... data, see qapi_event_throttle_equal() */
    QEMUTimer *timer;   /* Timer for handling delayed events */
    QDict *qdict;       /* Delayed event (if any) */
} MonitorQAPIEventState;

typedef struct {
    int64_t rate;       /* Minimum time (in ns) between two events */
} MonitorQAPIEventConf;

struct Monitor {
    CharBackend chr;
    int reset_seen;
    int flags;
    int suspend_cnt;            /* Needs to be accessed atomically */
    bool skip_flush;
    bool use_io_thread;

    /*
     * State used only in the thread "owning" the monitor.
     * If @use_io_thread, this is @mon_iothread.
     * Else, it's the main thread.
     * These members can be safely accessed without locks.
     */
    ReadLineState *rs;

    gchar *mon_cpu_path;
    mon_cmd_t *cmd_table;
    QTAILQ_ENTRY(Monitor) entry;

    /*
     * The per-monitor lock. We can't access guest memory when holding
     * the lock.
     */
    QemuMutex mon_lock;

    /*
     * Members that are protected by the per-monitor lock
     */
    QLIST_HEAD(, mon_fd_t) fds;
    QString *outbuf;
    guint out_watch;
    /* Read under either BQL or mon_lock, written with BQL+mon_lock.  */
    int mux_out;
};

typedef struct {
    Monitor common;
    JSONMessageParser parser;
    /*
     * When a client connects, we're in capabilities negotiation mode.
     * @commands is &qmp_cap_negotiation_commands then.  When command
     * qmp_capabilities succeeds, we go into command mode, and
     * @command becomes &qmp_commands.
     */
    QmpCommandList *commands;
    bool capab_offered[QMP_CAPABILITY__MAX]; /* capabilities offered */
    bool capab[QMP_CAPABILITY__MAX];         /* offered and accepted */
    /*
     * Protects qmp request/response queue.
     * Take monitor_lock first when you need both.
     */
    QemuMutex qmp_queue_lock;
    /* Input queue that holds all the parsed QMP requests */
    GQueue *qmp_requests;
} MonitorQMP;

/* Shared monitor I/O thread */
IOThread *mon_iothread;

/* Bottom half to dispatch the requests received from I/O thread */
QEMUBH *qmp_dispatcher_bh;

struct QMPRequest {
    /* Owner of the request */
    MonitorQMP *mon;
    /*
     * Request object to be handled or Error to be reported
     * (exactly one of them is non-null)
     */
    QObject *req;
    Error *err;
};
typedef struct QMPRequest QMPRequest;

/* QMP checker flags */
#define QMP_ACCEPT_UNKNOWNS 1

/* Protects mon_list, monitor_qapi_event_state, monitor_destroyed.  */
static QemuMutex monitor_lock;
static GHashTable *monitor_qapi_event_state;
static QTAILQ_HEAD(, Monitor) mon_list;
static bool monitor_destroyed;

/* Protects mon_fdsets */
static QemuMutex mon_fdsets_lock;
static QLIST_HEAD(, MonFdset) mon_fdsets;

static int mon_refcount;

static mon_cmd_t mon_cmds[];
static mon_cmd_t info_cmds[];

QmpCommandList qmp_commands, qmp_cap_negotiation_commands;

__thread Monitor *cur_mon;

static void monitor_command_cb(void *opaque, const char *cmdline,
                               void *readline_opaque);

/**
 * Is @mon a QMP monitor?
 */
static inline bool monitor_is_qmp(const Monitor *mon)
{
    return (mon->flags & MONITOR_USE_CONTROL);
}

/**
 * Is @mon is using readline?
 * Note: not all HMP monitors use readline, e.g., gdbserver has a
 * non-interactive HMP monitor, so readline is not used there.
 */
static inline bool monitor_uses_readline(const Monitor *mon)
{
    return mon->flags & MONITOR_USE_READLINE;
}

static inline bool monitor_is_hmp_non_interactive(const Monitor *mon)
{
    return !monitor_is_qmp(mon) && !monitor_uses_readline(mon);
}

/*
 * Return the clock to use for recording an event's time.
 * It's QEMU_CLOCK_REALTIME, except for qtests it's
 * QEMU_CLOCK_VIRTUAL, to support testing rate limits.
 * Beware: result is invalid before configure_accelerator().
 */
static inline QEMUClockType monitor_get_event_clock(void)
{
    return qtest_enabled() ? QEMU_CLOCK_VIRTUAL : QEMU_CLOCK_REALTIME;
}

/**
 * Is the current monitor, if any, a QMP monitor?
 */
bool monitor_cur_is_qmp(void)
{
    return cur_mon && monitor_is_qmp(cur_mon);
}

void monitor_read_command(Monitor *mon, int show_prompt)
{
    if (!mon->rs)
        return;

    readline_start(mon->rs, "(qemu) ", 0, monitor_command_cb, NULL);
    if (show_prompt)
        readline_show_prompt(mon->rs);
}

int monitor_read_password(Monitor *mon, ReadLineFunc *readline_func,
                          void *opaque)
{
    if (mon->rs) {
        readline_start(mon->rs, "Password: ", 1, readline_func, opaque);
        /* prompt is printed on return from the command handler */
        return 0;
    } else {
        monitor_printf(mon, "terminal does not support password prompting\n");
        return -ENOTTY;
    }
}

static void qmp_request_free(QMPRequest *req)
{
    qobject_unref(req->req);
    error_free(req->err);
    g_free(req);
}

/* Caller must hold mon->qmp.qmp_queue_lock */
static void monitor_qmp_cleanup_req_queue_locked(MonitorQMP *mon)
{
    while (!g_queue_is_empty(mon->qmp_requests)) {
        qmp_request_free(g_queue_pop_head(mon->qmp_requests));
    }
}

static void monitor_qmp_cleanup_queues(MonitorQMP *mon)
{
    qemu_mutex_lock(&mon->qmp_queue_lock);
    monitor_qmp_cleanup_req_queue_locked(mon);
    qemu_mutex_unlock(&mon->qmp_queue_lock);
}


static void monitor_flush_locked(Monitor *mon);

static gboolean monitor_unblocked(GIOChannel *chan, GIOCondition cond,
                                  void *opaque)
{
    Monitor *mon = opaque;

    qemu_mutex_lock(&mon->mon_lock);
    mon->out_watch = 0;
    monitor_flush_locked(mon);
    qemu_mutex_unlock(&mon->mon_lock);
    return FALSE;
}

/* Caller must hold mon->mon_lock */
static void monitor_flush_locked(Monitor *mon)
{
    int rc;
    size_t len;
    const char *buf;

    if (mon->skip_flush) {
        return;
    }

    buf = qstring_get_str(mon->outbuf);
    len = qstring_get_length(mon->outbuf);

    if (len && !mon->mux_out) {
        rc = qemu_chr_fe_write(&mon->chr, (const uint8_t *) buf, len);
        if ((rc < 0 && errno != EAGAIN) || (rc == len)) {
            /* all flushed or error */
            qobject_unref(mon->outbuf);
            mon->outbuf = qstring_new();
            return;
        }
        if (rc > 0) {
            /* partial write */
            QString *tmp = qstring_from_str(buf + rc);
            qobject_unref(mon->outbuf);
            mon->outbuf = tmp;
        }
        if (mon->out_watch == 0) {
            mon->out_watch =
                qemu_chr_fe_add_watch(&mon->chr, G_IO_OUT | G_IO_HUP,
                                      monitor_unblocked, mon);
        }
    }
}

void monitor_flush(Monitor *mon)
{
    qemu_mutex_lock(&mon->mon_lock);
    monitor_flush_locked(mon);
    qemu_mutex_unlock(&mon->mon_lock);
}

/* flush at every end of line */
static int monitor_puts(Monitor *mon, const char *str)
{
    int i;
    char c;

    qemu_mutex_lock(&mon->mon_lock);
    for (i = 0; str[i]; i++) {
        c = str[i];
        if (c == '\n') {
            qstring_append_chr(mon->outbuf, '\r');
        }
        qstring_append_chr(mon->outbuf, c);
        if (c == '\n') {
            monitor_flush_locked(mon);
        }
    }
    qemu_mutex_unlock(&mon->mon_lock);

    return i;
}

int monitor_vprintf(Monitor *mon, const char *fmt, va_list ap)
{
    char *buf;
    int n;

    if (!mon)
        return -1;

    if (monitor_is_qmp(mon)) {
        return -1;
    }

    buf = g_strdup_vprintf(fmt, ap);
    n = monitor_puts(mon, buf);
    g_free(buf);
    return n;
}

int monitor_printf(Monitor *mon, const char *fmt, ...)
{
    int ret;

    va_list ap;
    va_start(ap, fmt);
    ret = monitor_vprintf(mon, fmt, ap);
    va_end(ap);
    return ret;
}

static void qmp_send_response(MonitorQMP *mon, const QDict *rsp)
{
    const QObject *data = QOBJECT(rsp);
    QString *json;

    json = mon->common.flags & MONITOR_USE_PRETTY ?
           qobject_to_json_pretty(data) : qobject_to_json(data);
    assert(json != NULL);

    qstring_append_chr(json, '\n');
    monitor_puts(&mon->common, qstring_get_str(json));

    qobject_unref(json);
}

static MonitorQAPIEventConf monitor_qapi_event_conf[QAPI_EVENT__MAX] = {
    /* Limit guest-triggerable events to 1 per second */
    [QAPI_EVENT_RTC_CHANGE]        = { 1000 * SCALE_MS },
    [QAPI_EVENT_WATCHDOG]          = { 1000 * SCALE_MS },
    [QAPI_EVENT_BALLOON_CHANGE]    = { 1000 * SCALE_MS },
    [QAPI_EVENT_QUORUM_REPORT_BAD] = { 1000 * SCALE_MS },
    [QAPI_EVENT_QUORUM_FAILURE]    = { 1000 * SCALE_MS },
    [QAPI_EVENT_VSERPORT_CHANGE]   = { 1000 * SCALE_MS },
};

/*
 * Broadcast an event to all monitors.
 * @qdict is the event object.  Its member "event" must match @event.
 * Caller must hold monitor_lock.
 */
static void monitor_qapi_event_emit(QAPIEvent event, QDict *qdict)
{
    Monitor *mon;
    MonitorQMP *qmp_mon;

    trace_monitor_protocol_event_emit(event, qdict);
    QTAILQ_FOREACH(mon, &mon_list, entry) {
        if (!monitor_is_qmp(mon)) {
            continue;
        }

        qmp_mon = container_of(mon, MonitorQMP, common);
        if (qmp_mon->commands != &qmp_cap_negotiation_commands) {
            qmp_send_response(qmp_mon, qdict);
        }
    }
}

static void monitor_qapi_event_handler(void *opaque);

/*
 * Queue a new event for emission to Monitor instances,
 * applying any rate limiting if required.
 */
static void
monitor_qapi_event_queue_no_reenter(QAPIEvent event, QDict *qdict)
{
    MonitorQAPIEventConf *evconf;
    MonitorQAPIEventState *evstate;

    assert(event < QAPI_EVENT__MAX);
    evconf = &monitor_qapi_event_conf[event];
    trace_monitor_protocol_event_queue(event, qdict, evconf->rate);

    qemu_mutex_lock(&monitor_lock);

    if (!evconf->rate) {
        /* Unthrottled event */
        monitor_qapi_event_emit(event, qdict);
    } else {
        QDict *data = qobject_to(QDict, qdict_get(qdict, "data"));
        MonitorQAPIEventState key = { .event = event, .data = data };

        evstate = g_hash_table_lookup(monitor_qapi_event_state, &key);
        assert(!evstate || timer_pending(evstate->timer));

        if (evstate) {
            /*
             * Timer is pending for (at least) evconf->rate ns after
             * last send.  Store event for sending when timer fires,
             * replacing a prior stored event if any.
             */
            qobject_unref(evstate->qdict);
            evstate->qdict = qobject_ref(qdict);
        } else {
            /*
             * Last send was (at least) evconf->rate ns ago.
             * Send immediately, and arm the timer to call
             * monitor_qapi_event_handler() in evconf->rate ns.  Any
             * events arriving before then will be delayed until then.
             */
            int64_t now = qemu_clock_get_ns(monitor_get_event_clock());

            monitor_qapi_event_emit(event, qdict);

            evstate = g_new(MonitorQAPIEventState, 1);
            evstate->event = event;
            evstate->data = qobject_ref(data);
            evstate->qdict = NULL;
            evstate->timer = timer_new_ns(monitor_get_event_clock(),
                                          monitor_qapi_event_handler,
                                          evstate);
            g_hash_table_add(monitor_qapi_event_state, evstate);
            timer_mod_ns(evstate->timer, now + evconf->rate);
        }
    }

    qemu_mutex_unlock(&monitor_lock);
}

void qapi_event_emit(QAPIEvent event, QDict *qdict)
{
    /*
     * monitor_qapi_event_queue_no_reenter() is not reentrant: it
     * would deadlock on monitor_lock.  Work around by queueing
     * events in thread-local storage.
     * TODO: remove this, make it re-enter safe.
     */
    typedef struct MonitorQapiEvent {
        QAPIEvent event;
        QDict *qdict;
        QSIMPLEQ_ENTRY(MonitorQapiEvent) entry;
    } MonitorQapiEvent;
    static __thread QSIMPLEQ_HEAD(, MonitorQapiEvent) event_queue;
    static __thread bool reentered;
    MonitorQapiEvent *ev;

    if (!reentered) {
        QSIMPLEQ_INIT(&event_queue);
    }

    ev = g_new(MonitorQapiEvent, 1);
    ev->qdict = qobject_ref(qdict);
    ev->event = event;
    QSIMPLEQ_INSERT_TAIL(&event_queue, ev, entry);
    if (reentered) {
        return;
    }

    reentered = true;

    while ((ev = QSIMPLEQ_FIRST(&event_queue)) != NULL) {
        QSIMPLEQ_REMOVE_HEAD(&event_queue, entry);
        monitor_qapi_event_queue_no_reenter(ev->event, ev->qdict);
        qobject_unref(ev->qdict);
        g_free(ev);
    }

    reentered = false;
}

/*
 * This function runs evconf->rate ns after sending a throttled
 * event.
 * If another event has since been stored, send it.
 */
static void monitor_qapi_event_handler(void *opaque)
{
    MonitorQAPIEventState *evstate = opaque;
    MonitorQAPIEventConf *evconf = &monitor_qapi_event_conf[evstate->event];

    trace_monitor_protocol_event_handler(evstate->event, evstate->qdict);
    qemu_mutex_lock(&monitor_lock);

    if (evstate->qdict) {
        int64_t now = qemu_clock_get_ns(monitor_get_event_clock());

        monitor_qapi_event_emit(evstate->event, evstate->qdict);
        qobject_unref(evstate->qdict);
        evstate->qdict = NULL;
        timer_mod_ns(evstate->timer, now + evconf->rate);
    } else {
        g_hash_table_remove(monitor_qapi_event_state, evstate);
        qobject_unref(evstate->data);
        timer_free(evstate->timer);
        g_free(evstate);
    }

    qemu_mutex_unlock(&monitor_lock);
}

static unsigned int qapi_event_throttle_hash(const void *key)
{
    const MonitorQAPIEventState *evstate = key;
    unsigned int hash = evstate->event * 255;

    if (evstate->event == QAPI_EVENT_VSERPORT_CHANGE) {
        hash += g_str_hash(qdict_get_str(evstate->data, "id"));
    }

    if (evstate->event == QAPI_EVENT_QUORUM_REPORT_BAD) {
        hash += g_str_hash(qdict_get_str(evstate->data, "node-name"));
    }

    return hash;
}

static gboolean qapi_event_throttle_equal(const void *a, const void *b)
{
    const MonitorQAPIEventState *eva = a;
    const MonitorQAPIEventState *evb = b;

    if (eva->event != evb->event) {
        return FALSE;
    }

    if (eva->event == QAPI_EVENT_VSERPORT_CHANGE) {
        return !strcmp(qdict_get_str(eva->data, "id"),
                       qdict_get_str(evb->data, "id"));
    }

    if (eva->event == QAPI_EVENT_QUORUM_REPORT_BAD) {
        return !strcmp(qdict_get_str(eva->data, "node-name"),
                       qdict_get_str(evb->data, "node-name"));
    }

    return TRUE;
}

static void monitor_qapi_event_init(void)
{
    monitor_qapi_event_state = g_hash_table_new(qapi_event_throttle_hash,
                                                qapi_event_throttle_equal);
}

static void handle_hmp_command(Monitor *mon, const char *cmdline);

static void monitor_iothread_init(void);

static void monitor_data_init(Monitor *mon, int flags, bool skip_flush,
                              bool use_io_thread)
{
    if (use_io_thread && !mon_iothread) {
        monitor_iothread_init();
    }
    qemu_mutex_init(&mon->mon_lock);
    mon->outbuf = qstring_new();
    /* Use *mon_cmds by default. */
    mon->cmd_table = mon_cmds;
    mon->skip_flush = skip_flush;
    mon->use_io_thread = use_io_thread;
    mon->flags = flags;
}

static void monitor_data_destroy_qmp(MonitorQMP *mon)
{
    json_message_parser_destroy(&mon->parser);
    qemu_mutex_destroy(&mon->qmp_queue_lock);
    monitor_qmp_cleanup_req_queue_locked(mon);
    g_queue_free(mon->qmp_requests);
}

static void monitor_data_destroy(Monitor *mon)
{
    g_free(mon->mon_cpu_path);
    qemu_chr_fe_deinit(&mon->chr, false);
    if (monitor_is_qmp(mon)) {
        monitor_data_destroy_qmp(container_of(mon, MonitorQMP, common));
    }
    readline_free(mon->rs);
    qobject_unref(mon->outbuf);
    qemu_mutex_destroy(&mon->mon_lock);
}

char *qmp_human_monitor_command(const char *command_line, bool has_cpu_index,
                                int64_t cpu_index, Error **errp)
{
    char *output = NULL;
    Monitor *old_mon;
    Monitor hmp = {};

    monitor_data_init(&hmp, 0, true, false);

    old_mon = cur_mon;
    cur_mon = &hmp;

    if (has_cpu_index) {
        int ret = monitor_set_cpu(cpu_index);
        if (ret < 0) {
            cur_mon = old_mon;
            error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cpu-index",
                       "a CPU number");
            goto out;
        }
    }

    handle_hmp_command(&hmp, command_line);
    cur_mon = old_mon;

    qemu_mutex_lock(&hmp.mon_lock);
    if (qstring_get_length(hmp.outbuf) > 0) {
        output = g_strdup(qstring_get_str(hmp.outbuf));
    } else {
        output = g_strdup("");
    }
    qemu_mutex_unlock(&hmp.mon_lock);

out:
    monitor_data_destroy(&hmp);
    return output;
}

static int compare_cmd(const char *name, const char *list)
{
    const char *p, *pstart;
    int len;
    len = strlen(name);
    p = list;
    for(;;) {
        pstart = p;
        p = qemu_strchrnul(p, '|');
        if ((p - pstart) == len && !memcmp(pstart, name, len))
            return 1;
        if (*p == '\0')
            break;
        p++;
    }
    return 0;
}

static int get_str(char *buf, int buf_size, const char **pp)
{
    const char *p;
    char *q;
    int c;

    q = buf;
    p = *pp;
    while (qemu_isspace(*p)) {
        p++;
    }
    if (*p == '\0') {
    fail:
        *q = '\0';
        *pp = p;
        return -1;
    }
    if (*p == '\"') {
        p++;
        while (*p != '\0' && *p != '\"') {
            if (*p == '\\') {
                p++;
                c = *p++;
                switch (c) {
                case 'n':
                    c = '\n';
                    break;
                case 'r':
                    c = '\r';
                    break;
                case '\\':
                case '\'':
                case '\"':
                    break;
                default:
                    printf("unsupported escape code: '\\%c'\n", c);
                    goto fail;
                }
                if ((q - buf) < buf_size - 1) {
                    *q++ = c;
                }
            } else {
                if ((q - buf) < buf_size - 1) {
                    *q++ = *p;
                }
                p++;
            }
        }
        if (*p != '\"') {
            printf("unterminated string\n");
            goto fail;
        }
        p++;
    } else {
        while (*p != '\0' && !qemu_isspace(*p)) {
            if ((q - buf) < buf_size - 1) {
                *q++ = *p;
            }
            p++;
        }
    }
    *q = '\0';
    *pp = p;
    return 0;
}

#define MAX_ARGS 16

static void free_cmdline_args(char **args, int nb_args)
{
    int i;

    assert(nb_args <= MAX_ARGS);

    for (i = 0; i < nb_args; i++) {
        g_free(args[i]);
    }

}

/*
 * Parse the command line to get valid args.
 * @cmdline: command line to be parsed.
 * @pnb_args: location to store the number of args, must NOT be NULL.
 * @args: location to store the args, which should be freed by caller, must
 *        NOT be NULL.
 *
 * Returns 0 on success, negative on failure.
 *
 * NOTE: this parser is an approximate form of the real command parser. Number
 *       of args have a limit of MAX_ARGS. If cmdline contains more, it will
 *       return with failure.
 */
static int parse_cmdline(const char *cmdline,
                         int *pnb_args, char **args)
{
    const char *p;
    int nb_args, ret;
    char buf[1024];

    p = cmdline;
    nb_args = 0;
    for (;;) {
        while (qemu_isspace(*p)) {
            p++;
        }
        if (*p == '\0') {
            break;
        }
        if (nb_args >= MAX_ARGS) {
            goto fail;
        }
        ret = get_str(buf, sizeof(buf), &p);
        if (ret < 0) {
            goto fail;
        }
        args[nb_args] = g_strdup(buf);
        nb_args++;
    }
    *pnb_args = nb_args;
    return 0;

 fail:
    free_cmdline_args(args, nb_args);
    return -1;
}

/*
 * Can command @cmd be executed in preconfig state?
 */
static bool cmd_can_preconfig(const mon_cmd_t *cmd)
{
    if (!cmd->flags) {
        return false;
    }

    return strchr(cmd->flags, 'p');
}

static void help_cmd_dump_one(Monitor *mon,
                              const mon_cmd_t *cmd,
                              char **prefix_args,
                              int prefix_args_nb)
{
    int i;

    if (runstate_check(RUN_STATE_PRECONFIG) && !cmd_can_preconfig(cmd)) {
        return;
    }

    for (i = 0; i < prefix_args_nb; i++) {
        monitor_printf(mon, "%s ", prefix_args[i]);
    }
    monitor_printf(mon, "%s %s -- %s\n", cmd->name, cmd->params, cmd->help);
}

/* @args[@arg_index] is the valid command need to find in @cmds */
static void help_cmd_dump(Monitor *mon, const mon_cmd_t *cmds,
                          char **args, int nb_args, int arg_index)
{
    const mon_cmd_t *cmd;
    size_t i;

    /* No valid arg need to compare with, dump all in *cmds */
    if (arg_index >= nb_args) {
        for (cmd = cmds; cmd->name != NULL; cmd++) {
            help_cmd_dump_one(mon, cmd, args, arg_index);
        }
        return;
    }

    /* Find one entry to dump */
    for (cmd = cmds; cmd->name != NULL; cmd++) {
        if (compare_cmd(args[arg_index], cmd->name) &&
            ((!runstate_check(RUN_STATE_PRECONFIG) ||
                cmd_can_preconfig(cmd)))) {
            if (cmd->sub_table) {
                /* continue with next arg */
                help_cmd_dump(mon, cmd->sub_table,
                              args, nb_args, arg_index + 1);
            } else {
                help_cmd_dump_one(mon, cmd, args, arg_index);
            }
            return;
        }
    }

    /* Command not found */
    monitor_printf(mon, "unknown command: '");
    for (i = 0; i <= arg_index; i++) {
        monitor_printf(mon, "%s%s", args[i], i == arg_index ? "'\n" : " ");
    }
}

static void help_cmd(Monitor *mon, const char *name)
{
    char *args[MAX_ARGS];
    int nb_args = 0;

    /* 1. parse user input */
    if (name) {
        /* special case for log, directly dump and return */
        if (!strcmp(name, "log")) {
            const QEMULogItem *item;
            monitor_printf(mon, "Log items (comma separated):\n");
            monitor_printf(mon, "%-10s %s\n", "none", "remove all logs");
            for (item = qemu_log_items; item->mask != 0; item++) {
                monitor_printf(mon, "%-10s %s\n", item->name, item->help);
            }
            return;
        }

        if (parse_cmdline(name, &nb_args, args) < 0) {
            return;
        }
    }

    /* 2. dump the contents according to parsed args */
    help_cmd_dump(mon, mon->cmd_table, args, nb_args, 0);

    free_cmdline_args(args, nb_args);
}

static void do_help_cmd(Monitor *mon, const QDict *qdict)
{
    help_cmd(mon, qdict_get_try_str(qdict, "name"));
}

static void hmp_trace_event(Monitor *mon, const QDict *qdict)
{
    const char *tp_name = qdict_get_str(qdict, "name");
    bool new_state = qdict_get_bool(qdict, "option");
    bool has_vcpu = qdict_haskey(qdict, "vcpu");
    int vcpu = qdict_get_try_int(qdict, "vcpu", 0);
    Error *local_err = NULL;

    if (vcpu < 0) {
        monitor_printf(mon, "argument vcpu must be positive");
        return;
    }

    qmp_trace_event_set_state(tp_name, new_state, true, true, has_vcpu, vcpu, &local_err);
    if (local_err) {
        error_report_err(local_err);
    }
}

#ifdef CONFIG_TRACE_SIMPLE
static void hmp_trace_file(Monitor *mon, const QDict *qdict)
{
    const char *op = qdict_get_try_str(qdict, "op");
    const char *arg = qdict_get_try_str(qdict, "arg");

    if (!op) {
        st_print_trace_file_status();
    } else if (!strcmp(op, "on")) {
        st_set_trace_file_enabled(true);
    } else if (!strcmp(op, "off")) {
        st_set_trace_file_enabled(false);
    } else if (!strcmp(op, "flush")) {
        st_flush_trace_buffer();
    } else if (!strcmp(op, "set")) {
        if (arg) {
            st_set_trace_file(arg);
        }
    } else {
        monitor_printf(mon, "unexpected argument \"%s\"\n", op);
        help_cmd(mon, "trace-file");
    }
}
#endif

static void hmp_info_help(Monitor *mon, const QDict *qdict)
{
    help_cmd(mon, "info");
}

static void query_commands_cb(QmpCommand *cmd, void *opaque)
{
    CommandInfoList *info, **list = opaque;

    if (!cmd->enabled) {
        return;
    }

    info = g_malloc0(sizeof(*info));
    info->value = g_malloc0(sizeof(*info->value));
    info->value->name = g_strdup(cmd->name);
    info->next = *list;
    *list = info;
}

CommandInfoList *qmp_query_commands(Error **errp)
{
    CommandInfoList *list = NULL;
    MonitorQMP *mon;

    assert(monitor_is_qmp(cur_mon));
    mon = container_of(cur_mon, MonitorQMP, common);

    qmp_for_each_command(mon->commands, query_commands_cb, &list);

    return list;
}

EventInfoList *qmp_query_events(Error **errp)
{
    /*
     * TODO This deprecated command is the only user of
     * QAPIEvent_str() and QAPIEvent_lookup[].  When the command goes,
     * they should go, too.
     */
    EventInfoList *info, *ev_list = NULL;
    QAPIEvent e;

    for (e = 0 ; e < QAPI_EVENT__MAX ; e++) {
        const char *event_name = QAPIEvent_str(e);
        assert(event_name != NULL);
        info = g_malloc0(sizeof(*info));
        info->value = g_malloc0(sizeof(*info->value));
        info->value->name = g_strdup(event_name);

        info->next = ev_list;
        ev_list = info;
    }

    return ev_list;
}

/*
 * Minor hack: generated marshalling suppressed for this command
 * ('gen': false in the schema) so we can parse the JSON string
 * directly into QObject instead of first parsing it with
 * visit_type_SchemaInfoList() into a SchemaInfoList, then marshal it
 * to QObject with generated output marshallers, every time.  Instead,
 * we do it in test-qobject-input-visitor.c, just to make sure
 * qapi-gen.py's output actually conforms to the schema.
 */
static void qmp_query_qmp_schema(QDict *qdict, QObject **ret_data,
                                 Error **errp)
{
    *ret_data = qobject_from_qlit(&qmp_schema_qlit);
}

static void monitor_init_qmp_commands(void)
{
    /*
     * Two command lists:
     * - qmp_commands contains all QMP commands
     * - qmp_cap_negotiation_commands contains just
     *   "qmp_capabilities", to enforce capability negotiation
     */

    qmp_init_marshal(&qmp_commands);

    qmp_register_command(&qmp_commands, "query-qmp-schema",
                         qmp_query_qmp_schema, QCO_ALLOW_PRECONFIG);
    qmp_register_command(&qmp_commands, "device_add", qmp_device_add,
                         QCO_NO_OPTIONS);
    qmp_register_command(&qmp_commands, "netdev_add", qmp_netdev_add,
                         QCO_NO_OPTIONS);

    QTAILQ_INIT(&qmp_cap_negotiation_commands);
    qmp_register_command(&qmp_cap_negotiation_commands, "qmp_capabilities",
                         qmp_marshal_qmp_capabilities, QCO_ALLOW_PRECONFIG);
}

static bool qmp_oob_enabled(MonitorQMP *mon)
{
    return mon->capab[QMP_CAPABILITY_OOB];
}

static void monitor_qmp_caps_reset(MonitorQMP *mon)
{
    memset(mon->capab_offered, 0, sizeof(mon->capab_offered));
    memset(mon->capab, 0, sizeof(mon->capab));
    mon->capab_offered[QMP_CAPABILITY_OOB] = mon->common.use_io_thread;
}

/*
 * Accept QMP capabilities in @list for @mon.
 * On success, set mon->qmp.capab[], and return true.
 * On error, set @errp, and return false.
 */
static bool qmp_caps_accept(MonitorQMP *mon, QMPCapabilityList *list,
                            Error **errp)
{
    GString *unavailable = NULL;
    bool capab[QMP_CAPABILITY__MAX];

    memset(capab, 0, sizeof(capab));

    for (; list; list = list->next) {
        if (!mon->capab_offered[list->value]) {
            if (!unavailable) {
                unavailable = g_string_new(QMPCapability_str(list->value));
            } else {
                g_string_append_printf(unavailable, ", %s",
                                      QMPCapability_str(list->value));
            }
        }
        capab[list->value] = true;
    }

    if (unavailable) {
        error_setg(errp, "Capability %s not available", unavailable->str);
        g_string_free(unavailable, true);
        return false;
    }

    memcpy(mon->capab, capab, sizeof(capab));
    return true;
}

void qmp_qmp_capabilities(bool has_enable, QMPCapabilityList *enable,
                          Error **errp)
{
    MonitorQMP *mon;

    assert(monitor_is_qmp(cur_mon));
    mon = container_of(cur_mon, MonitorQMP, common);

    if (mon->commands == &qmp_commands) {
        error_set(errp, ERROR_CLASS_COMMAND_NOT_FOUND,
                  "Capabilities negotiation is already complete, command "
                  "ignored");
        return;
    }

    if (!qmp_caps_accept(mon, enable, errp)) {
        return;
    }

    mon->commands = &qmp_commands;
}

/* Set the current CPU defined by the user. Callers must hold BQL. */
int monitor_set_cpu(int cpu_index)
{
    CPUState *cpu;

    cpu = qemu_get_cpu(cpu_index);
    if (cpu == NULL) {
        return -1;
    }
    g_free(cur_mon->mon_cpu_path);
    cur_mon->mon_cpu_path = object_get_canonical_path(OBJECT(cpu));
    return 0;
}

/* Callers must hold BQL. */
static CPUState *mon_get_cpu_sync(bool synchronize)
{
    CPUState *cpu;

    if (cur_mon->mon_cpu_path) {
        cpu = (CPUState *) object_resolve_path_type(cur_mon->mon_cpu_path,
                                                    TYPE_CPU, NULL);
        if (!cpu) {
            g_free(cur_mon->mon_cpu_path);
            cur_mon->mon_cpu_path = NULL;
        }
    }
    if (!cur_mon->mon_cpu_path) {
        if (!first_cpu) {
            return NULL;
        }
        monitor_set_cpu(first_cpu->cpu_index);
        cpu = first_cpu;
    }
    if (synchronize) {
        cpu_synchronize_state(cpu);
    }
    return cpu;
}

CPUState *mon_get_cpu(void)
{
    return mon_get_cpu_sync(true);
}

CPUArchState *mon_get_cpu_env(void)
{
    CPUState *cs = mon_get_cpu();

    return cs ? cs->env_ptr : NULL;
}

int monitor_get_cpu_index(void)
{
    CPUState *cs = mon_get_cpu_sync(false);

    return cs ? cs->cpu_index : UNASSIGNED_CPU_INDEX;
}

static void hmp_info_registers(Monitor *mon, const QDict *qdict)
{
    bool all_cpus = qdict_get_try_bool(qdict, "cpustate_all", false);
    CPUState *cs;

    if (all_cpus) {
        CPU_FOREACH(cs) {
            monitor_printf(mon, "\nCPU#%d\n", cs->cpu_index);
            cpu_dump_state(cs, NULL, CPU_DUMP_FPU);
        }
    } else {
        cs = mon_get_cpu();

        if (!cs) {
            monitor_printf(mon, "No CPU available\n");
            return;
        }

        cpu_dump_state(cs, NULL, CPU_DUMP_FPU);
    }
}

#ifdef CONFIG_TCG
static void hmp_info_jit(Monitor *mon, const QDict *qdict)
{
    if (!tcg_enabled()) {
        error_report("JIT information is only available with accel=tcg");
        return;
    }

    dump_exec_info();
    dump_drift_info();
}

static void hmp_info_opcount(Monitor *mon, const QDict *qdict)
{
    dump_opcount_info();
}
#endif

static void hmp_info_sync_profile(Monitor *mon, const QDict *qdict)
{
    int64_t max = qdict_get_try_int(qdict, "max", 10);
    bool mean = qdict_get_try_bool(qdict, "mean", false);
    bool coalesce = !qdict_get_try_bool(qdict, "no_coalesce", false);
    enum QSPSortBy sort_by;

    sort_by = mean ? QSP_SORT_BY_AVG_WAIT_TIME : QSP_SORT_BY_TOTAL_WAIT_TIME;
    qsp_report(max, sort_by, coalesce);
}

static void hmp_info_history(Monitor *mon, const QDict *qdict)
{
    int i;
    const char *str;

    if (!mon->rs)
        return;
    i = 0;
    for(;;) {
        str = readline_get_history(mon->rs, i);
        if (!str)
            break;
        monitor_printf(mon, "%d: '%s'\n", i, str);
        i++;
    }
}

static void hmp_info_cpustats(Monitor *mon, const QDict *qdict)
{
    CPUState *cs = mon_get_cpu();

    if (!cs) {
        monitor_printf(mon, "No CPU available\n");
        return;
    }
    cpu_dump_statistics(cs, 0);
}

static void hmp_info_trace_events(Monitor *mon, const QDict *qdict)
{
    const char *name = qdict_get_try_str(qdict, "name");
    bool has_vcpu = qdict_haskey(qdict, "vcpu");
    int vcpu = qdict_get_try_int(qdict, "vcpu", 0);
    TraceEventInfoList *events;
    TraceEventInfoList *elem;
    Error *local_err = NULL;

    if (name == NULL) {
        name = "*";
    }
    if (vcpu < 0) {
        monitor_printf(mon, "argument vcpu must be positive");
        return;
    }

    events = qmp_trace_event_get_state(name, has_vcpu, vcpu, &local_err);
    if (local_err) {
        error_report_err(local_err);
        return;
    }

    for (elem = events; elem != NULL; elem = elem->next) {
        monitor_printf(mon, "%s : state %u\n",
                       elem->value->name,
                       elem->value->state == TRACE_EVENT_STATE_ENABLED ? 1 : 0);
    }
    qapi_free_TraceEventInfoList(events);
}

void qmp_client_migrate_info(const char *protocol, const char *hostname,
                             bool has_port, int64_t port,
                             bool has_tls_port, int64_t tls_port,
                             bool has_cert_subject, const char *cert_subject,
                             Error **errp)
{
    if (strcmp(protocol, "spice") == 0) {
        if (!qemu_using_spice(errp)) {
            return;
        }

        if (!has_port && !has_tls_port) {
            error_setg(errp, QERR_MISSING_PARAMETER, "port/tls-port");
            return;
        }

        if (qemu_spice_migrate_info(hostname,
                                    has_port ? port : -1,
                                    has_tls_port ? tls_port : -1,
                                    cert_subject)) {
            error_setg(errp, QERR_UNDEFINED_ERROR);
            return;
        }
        return;
    }

    error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "protocol", "spice");
}

static void hmp_logfile(Monitor *mon, const QDict *qdict)
{
    Error *err = NULL;

    qemu_set_log_filename(qdict_get_str(qdict, "filename"), &err);
    if (err) {
        error_report_err(err);
    }
}

static void hmp_log(Monitor *mon, const QDict *qdict)
{
    int mask;
    const char *items = qdict_get_str(qdict, "items");

    if (!strcmp(items, "none")) {
        mask = 0;
    } else {
        mask = qemu_str_to_log_mask(items);
        if (!mask) {
            help_cmd(mon, "log");
            return;
        }
    }
    qemu_set_log(mask);
}

static void hmp_singlestep(Monitor *mon, const QDict *qdict)
{
    const char *option = qdict_get_try_str(qdict, "option");
    if (!option || !strcmp(option, "on")) {
        singlestep = 1;
    } else if (!strcmp(option, "off")) {
        singlestep = 0;
    } else {
        monitor_printf(mon, "unexpected option %s\n", option);
    }
}

static void hmp_gdbserver(Monitor *mon, const QDict *qdict)
{
    const char *device = qdict_get_try_str(qdict, "device");
    if (!device)
        device = "tcp::" DEFAULT_GDBSTUB_PORT;
    if (gdbserver_start(device) < 0) {
        monitor_printf(mon, "Could not open gdbserver on device '%s'\n",
                       device);
    } else if (strcmp(device, "none") == 0) {
        monitor_printf(mon, "Disabled gdbserver\n");
    } else {
        monitor_printf(mon, "Waiting for gdb connection on device '%s'\n",
                       device);
    }
}

static void hmp_watchdog_action(Monitor *mon, const QDict *qdict)
{
    const char *action = qdict_get_str(qdict, "action");
    if (select_watchdog_action(action) == -1) {
        monitor_printf(mon, "Unknown watchdog action '%s'\n", action);
    }
}

static void monitor_printc(Monitor *mon, int c)
{
    monitor_printf(mon, "'");
    switch(c) {
    case '\'':
        monitor_printf(mon, "\\'");
        break;
    case '\\':
        monitor_printf(mon, "\\\\");
        break;
    case '\n':
        monitor_printf(mon, "\\n");
        break;
    case '\r':
        monitor_printf(mon, "\\r");
        break;
    default:
        if (c >= 32 && c <= 126) {
            monitor_printf(mon, "%c", c);
        } else {
            monitor_printf(mon, "\\x%02x", c);
        }
        break;
    }
    monitor_printf(mon, "'");
}

static void memory_dump(Monitor *mon, int count, int format, int wsize,
                        hwaddr addr, int is_physical)
{
    int l, line_size, i, max_digits, len;
    uint8_t buf[16];
    uint64_t v;
    CPUState *cs = mon_get_cpu();

    if (!cs && (format == 'i' || !is_physical)) {
        monitor_printf(mon, "Can not dump without CPU\n");
        return;
    }

    if (format == 'i') {
        monitor_disas(mon, cs, addr, count, is_physical);
        return;
    }

    len = wsize * count;
    if (wsize == 1)
        line_size = 8;
    else
        line_size = 16;
    max_digits = 0;

    switch(format) {
    case 'o':
        max_digits = DIV_ROUND_UP(wsize * 8, 3);
        break;
    default:
    case 'x':
        max_digits = (wsize * 8) / 4;
        break;
    case 'u':
    case 'd':
        max_digits = DIV_ROUND_UP(wsize * 8 * 10, 33);
        break;
    case 'c':
        wsize = 1;
        break;
    }

    while (len > 0) {
        if (is_physical)
            monitor_printf(mon, TARGET_FMT_plx ":", addr);
        else
            monitor_printf(mon, TARGET_FMT_lx ":", (target_ulong)addr);
        l = len;
        if (l > line_size)
            l = line_size;
        if (is_physical) {
            AddressSpace *as = cs ? cs->as : &address_space_memory;
            MemTxResult r = address_space_read(as, addr,
                                               MEMTXATTRS_UNSPECIFIED, buf, l);
            if (r != MEMTX_OK) {
                monitor_printf(mon, " Cannot access memory\n");
                break;
            }
        } else {
            if (cpu_memory_rw_debug(cs, addr, buf, l, 0) < 0) {
                monitor_printf(mon, " Cannot access memory\n");
                break;
            }
        }
        i = 0;
        while (i < l) {
            switch(wsize) {
            default:
            case 1:
                v = ldub_p(buf + i);
                break;
            case 2:
                v = lduw_p(buf + i);
                break;
            case 4:
                v = (uint32_t)ldl_p(buf + i);
                break;
            case 8:
                v = ldq_p(buf + i);
                break;
            }
            monitor_printf(mon, " ");
            switch(format) {
            case 'o':
                monitor_printf(mon, "%#*" PRIo64, max_digits, v);
                break;
            case 'x':
                monitor_printf(mon, "0x%0*" PRIx64, max_digits, v);
                break;
            case 'u':
                monitor_printf(mon, "%*" PRIu64, max_digits, v);
                break;
            case 'd':
                monitor_printf(mon, "%*" PRId64, max_digits, v);
                break;
            case 'c':
                monitor_printc(mon, v);
                break;
            }
            i += wsize;
        }
        monitor_printf(mon, "\n");
        addr += l;
        len -= l;
    }
}

static void hmp_memory_dump(Monitor *mon, const QDict *qdict)
{
    int count = qdict_get_int(qdict, "count");
    int format = qdict_get_int(qdict, "format");
    int size = qdict_get_int(qdict, "size");
    target_long addr = qdict_get_int(qdict, "addr");

    memory_dump(mon, count, format, size, addr, 0);
}

static void hmp_physical_memory_dump(Monitor *mon, const QDict *qdict)
{
    int count = qdict_get_int(qdict, "count");
    int format = qdict_get_int(qdict, "format");
    int size = qdict_get_int(qdict, "size");
    hwaddr addr = qdict_get_int(qdict, "addr");

    memory_dump(mon, count, format, size, addr, 1);
}

static void *gpa2hva(MemoryRegion **p_mr, hwaddr addr, Error **errp)
{
    MemoryRegionSection mrs = memory_region_find(get_system_memory(),
                                                 addr, 1);

    if (!mrs.mr) {
        error_setg(errp, "No memory is mapped at address 0x%" HWADDR_PRIx, addr);
        return NULL;
    }

    if (!memory_region_is_ram(mrs.mr) && !memory_region_is_romd(mrs.mr)) {
        error_setg(errp, "Memory at address 0x%" HWADDR_PRIx "is not RAM", addr);
        memory_region_unref(mrs.mr);
        return NULL;
    }

    *p_mr = mrs.mr;
    return qemu_map_ram_ptr(mrs.mr->ram_block, mrs.offset_within_region);
}

static void hmp_gpa2hva(Monitor *mon, const QDict *qdict)
{
    hwaddr addr = qdict_get_int(qdict, "addr");
    Error *local_err = NULL;
    MemoryRegion *mr = NULL;
    void *ptr;

    ptr = gpa2hva(&mr, addr, &local_err);
    if (local_err) {
        error_report_err(local_err);
        return;
    }

    monitor_printf(mon, "Host virtual address for 0x%" HWADDR_PRIx
                   " (%s) is %p\n",
                   addr, mr->name, ptr);

    memory_region_unref(mr);
}

static void hmp_gva2gpa(Monitor *mon, const QDict *qdict)
{
    target_ulong addr = qdict_get_int(qdict, "addr");
    MemTxAttrs attrs;
    CPUState *cs = mon_get_cpu();
    hwaddr gpa;

    if (!cs) {
        monitor_printf(mon, "No cpu\n");
        return;
    }

    gpa  = cpu_get_phys_page_attrs_debug(cs, addr & TARGET_PAGE_MASK, &attrs);
    if (gpa == -1) {
        monitor_printf(mon, "Unmapped\n");
    } else {
        monitor_printf(mon, "gpa: %#" HWADDR_PRIx "\n",
                       gpa + (addr & ~TARGET_PAGE_MASK));
    }
}

#ifdef CONFIG_LINUX
static uint64_t vtop(void *ptr, Error **errp)
{
    uint64_t pinfo;
    uint64_t ret = -1;
    uintptr_t addr = (uintptr_t) ptr;
    uintptr_t pagesize = getpagesize();
    off_t offset = addr / pagesize * sizeof(pinfo);
    int fd;

    fd = open("/proc/self/pagemap", O_RDONLY);
    if (fd == -1) {
        error_setg_errno(errp, errno, "Cannot open /proc/self/pagemap");
        return -1;
    }

    /* Force copy-on-write if necessary.  */
    atomic_add((uint8_t *)ptr, 0);

    if (pread(fd, &pinfo, sizeof(pinfo), offset) != sizeof(pinfo)) {
        error_setg_errno(errp, errno, "Cannot read pagemap");
        goto out;
    }
    if ((pinfo & (1ull << 63)) == 0) {
        error_setg(errp, "Page not present");
        goto out;
    }
    ret = ((pinfo & 0x007fffffffffffffull) * pagesize) | (addr & (pagesize - 1));

out:
    close(fd);
    return ret;
}

static void hmp_gpa2hpa(Monitor *mon, const QDict *qdict)
{
    hwaddr addr = qdict_get_int(qdict, "addr");
    Error *local_err = NULL;
    MemoryRegion *mr = NULL;
    void *ptr;
    uint64_t physaddr;

    ptr = gpa2hva(&mr, addr, &local_err);
    if (local_err) {
        error_report_err(local_err);
        return;
    }

    physaddr = vtop(ptr, &local_err);
    if (local_err) {
        error_report_err(local_err);
    } else {
        monitor_printf(mon, "Host physical address for 0x%" HWADDR_PRIx
                       " (%s) is 0x%" PRIx64 "\n",
                       addr, mr->name, (uint64_t) physaddr);
    }

    memory_region_unref(mr);
}
#endif

static void do_print(Monitor *mon, const QDict *qdict)
{
    int format = qdict_get_int(qdict, "format");
    hwaddr val = qdict_get_int(qdict, "val");

    switch(format) {
    case 'o':
        monitor_printf(mon, "%#" HWADDR_PRIo, val);
        break;
    case 'x':
        monitor_printf(mon, "%#" HWADDR_PRIx, val);
        break;
    case 'u':
        monitor_printf(mon, "%" HWADDR_PRIu, val);
        break;
    default:
    case 'd':
        monitor_printf(mon, "%" HWADDR_PRId, val);
        break;
    case 'c':
        monitor_printc(mon, val);
        break;
    }
    monitor_printf(mon, "\n");
}

static void hmp_sum(Monitor *mon, const QDict *qdict)
{
    uint32_t addr;
    uint16_t sum;
    uint32_t start = qdict_get_int(qdict, "start");
    uint32_t size = qdict_get_int(qdict, "size");

    sum = 0;
    for(addr = start; addr < (start + size); addr++) {
        uint8_t val = address_space_ldub(&address_space_memory, addr,
                                         MEMTXATTRS_UNSPECIFIED, NULL);
        /* BSD sum algorithm ('sum' Unix command) */
        sum = (sum >> 1) | (sum << 15);
        sum += val;
    }
    monitor_printf(mon, "%05d\n", sum);
}

static int mouse_button_state;

static void hmp_mouse_move(Monitor *mon, const QDict *qdict)
{
    int dx, dy, dz, button;
    const char *dx_str = qdict_get_str(qdict, "dx_str");
    const char *dy_str = qdict_get_str(qdict, "dy_str");
    const char *dz_str = qdict_get_try_str(qdict, "dz_str");

    dx = strtol(dx_str, NULL, 0);
    dy = strtol(dy_str, NULL, 0);
    qemu_input_queue_rel(NULL, INPUT_AXIS_X, dx);
    qemu_input_queue_rel(NULL, INPUT_AXIS_Y, dy);

    if (dz_str) {
        dz = strtol(dz_str, NULL, 0);
        if (dz != 0) {
            button = (dz > 0) ? INPUT_BUTTON_WHEEL_UP : INPUT_BUTTON_WHEEL_DOWN;
            qemu_input_queue_btn(NULL, button, true);
            qemu_input_event_sync();
            qemu_input_queue_btn(NULL, button, false);
        }
    }
    qemu_input_event_sync();
}

static void hmp_mouse_button(Monitor *mon, const QDict *qdict)
{
    static uint32_t bmap[INPUT_BUTTON__MAX] = {
        [INPUT_BUTTON_LEFT]       = MOUSE_EVENT_LBUTTON,
        [INPUT_BUTTON_MIDDLE]     = MOUSE_EVENT_MBUTTON,
        [INPUT_BUTTON_RIGHT]      = MOUSE_EVENT_RBUTTON,
    };
    int button_state = qdict_get_int(qdict, "button_state");

    if (mouse_button_state == button_state) {
        return;
    }
    qemu_input_update_buttons(NULL, bmap, mouse_button_state, button_state);
    qemu_input_event_sync();
    mouse_button_state = button_state;
}

static void hmp_ioport_read(Monitor *mon, const QDict *qdict)
{
    int size = qdict_get_int(qdict, "size");
    int addr = qdict_get_int(qdict, "addr");
    int has_index = qdict_haskey(qdict, "index");
    uint32_t val;
    int suffix;

    if (has_index) {
        int index = qdict_get_int(qdict, "index");
        cpu_outb(addr & IOPORTS_MASK, index & 0xff);
        addr++;
    }
    addr &= 0xffff;

    switch(size) {
    default:
    case 1:
        val = cpu_inb(addr);
        suffix = 'b';
        break;
    case 2:
        val = cpu_inw(addr);
        suffix = 'w';
        break;
    case 4:
        val = cpu_inl(addr);
        suffix = 'l';
        break;
    }
    monitor_printf(mon, "port%c[0x%04x] = %#0*x\n",
                   suffix, addr, size * 2, val);
}

static void hmp_ioport_write(Monitor *mon, const QDict *qdict)
{
    int size = qdict_get_int(qdict, "size");
    int addr = qdict_get_int(qdict, "addr");
    int val = qdict_get_int(qdict, "val");

    addr &= IOPORTS_MASK;

    switch (size) {
    default:
    case 1:
        cpu_outb(addr, val);
        break;
    case 2:
        cpu_outw(addr, val);
        break;
    case 4:
        cpu_outl(addr, val);
        break;
    }
}

static void hmp_boot_set(Monitor *mon, const QDict *qdict)
{
    Error *local_err = NULL;
    const char *bootdevice = qdict_get_str(qdict, "bootdevice");

    qemu_boot_set(bootdevice, &local_err);
    if (local_err) {
        error_report_err(local_err);
    } else {
        monitor_printf(mon, "boot device list now set to %s\n", bootdevice);
    }
}

static void hmp_info_mtree(Monitor *mon, const QDict *qdict)
{
    bool flatview = qdict_get_try_bool(qdict, "flatview", false);
    bool dispatch_tree = qdict_get_try_bool(qdict, "dispatch_tree", false);
    bool owner = qdict_get_try_bool(qdict, "owner", false);

    mtree_info(flatview, dispatch_tree, owner);
}

static void hmp_info_numa(Monitor *mon, const QDict *qdict)
{
    int i;
    NumaNodeMem *node_mem;
    CpuInfoList *cpu_list, *cpu;

    cpu_list = qmp_query_cpus(&error_abort);
    node_mem = g_new0(NumaNodeMem, nb_numa_nodes);

    query_numa_node_mem(node_mem);
    monitor_printf(mon, "%d nodes\n", nb_numa_nodes);
    for (i = 0; i < nb_numa_nodes; i++) {
        monitor_printf(mon, "node %d cpus:", i);
        for (cpu = cpu_list; cpu; cpu = cpu->next) {
            if (cpu->value->has_props && cpu->value->props->has_node_id &&
                cpu->value->props->node_id == i) {
                monitor_printf(mon, " %" PRIi64, cpu->value->CPU);
            }
        }
        monitor_printf(mon, "\n");
        monitor_printf(mon, "node %d size: %" PRId64 " MB\n", i,
                       node_mem[i].node_mem >> 20);
        monitor_printf(mon, "node %d plugged: %" PRId64 " MB\n", i,
                       node_mem[i].node_plugged_mem >> 20);
    }
    qapi_free_CpuInfoList(cpu_list);
    g_free(node_mem);
}

#ifdef CONFIG_PROFILER

int64_t dev_time;

static void hmp_info_profile(Monitor *mon, const QDict *qdict)
{
    static int64_t last_cpu_exec_time;
    int64_t cpu_exec_time;
    int64_t delta;

    cpu_exec_time = tcg_cpu_exec_time();
    delta = cpu_exec_time - last_cpu_exec_time;

    monitor_printf(mon, "async time  %" PRId64 " (%0.3f)\n",
                   dev_time, dev_time / (double)NANOSECONDS_PER_SECOND);
    monitor_printf(mon, "qemu time   %" PRId64 " (%0.3f)\n",
                   delta, delta / (double)NANOSECONDS_PER_SECOND);
    last_cpu_exec_time = cpu_exec_time;
    dev_time = 0;
}
#else
static void hmp_info_profile(Monitor *mon, const QDict *qdict)
{
    monitor_printf(mon, "Internal profiler not compiled\n");
}
#endif

/* Capture support */
static QLIST_HEAD (capture_list_head, CaptureState) capture_head;

static void hmp_info_capture(Monitor *mon, const QDict *qdict)
{
    int i;
    CaptureState *s;

    for (s = capture_head.lh_first, i = 0; s; s = s->entries.le_next, ++i) {
        monitor_printf(mon, "[%d]: ", i);
        s->ops.info (s->opaque);
    }
}

static void hmp_stopcapture(Monitor *mon, const QDict *qdict)
{
    int i;
    int n = qdict_get_int(qdict, "n");
    CaptureState *s;

    for (s = capture_head.lh_first, i = 0; s; s = s->entries.le_next, ++i) {
        if (i == n) {
            s->ops.destroy (s->opaque);
            QLIST_REMOVE (s, entries);
            g_free (s);
            return;
        }
    }
}

static void hmp_wavcapture(Monitor *mon, const QDict *qdict)
{
    const char *path = qdict_get_str(qdict, "path");
    int has_freq = qdict_haskey(qdict, "freq");
    int freq = qdict_get_try_int(qdict, "freq", -1);
    int has_bits = qdict_haskey(qdict, "bits");
    int bits = qdict_get_try_int(qdict, "bits", -1);
    int has_channels = qdict_haskey(qdict, "nchannels");
    int nchannels = qdict_get_try_int(qdict, "nchannels", -1);
    CaptureState *s;

    s = g_malloc0 (sizeof (*s));

    freq = has_freq ? freq : 44100;
    bits = has_bits ? bits : 16;
    nchannels = has_channels ? nchannels : 2;

    if (wav_start_capture (s, path, freq, bits, nchannels)) {
        monitor_printf(mon, "Failed to add wave capture\n");
        g_free (s);
        return;
    }
    QLIST_INSERT_HEAD (&capture_head, s, entries);
}

static QAuthZList *find_auth(Monitor *mon, const char *name)
{
    Object *obj;
    Object *container;

    container = object_get_objects_root();
    obj = object_resolve_path_component(container, name);
    if (!obj) {
        monitor_printf(mon, "acl: unknown list '%s'\n", name);
        return NULL;
    }

    return QAUTHZ_LIST(obj);
}

static bool warn_acl;
static void hmp_warn_acl(void)
{
    if (warn_acl) {
        return;
    }
    error_report("The acl_show, acl_reset, acl_policy, acl_add, acl_remove "
                 "commands are deprecated with no replacement. Authorization "
                 "for VNC should be performed using the pluggable QAuthZ "
                 "objects");
    warn_acl = true;
}

static void hmp_acl_show(Monitor *mon, const QDict *qdict)
{
    const char *aclname = qdict_get_str(qdict, "aclname");
    QAuthZList *auth = find_auth(mon, aclname);
    QAuthZListRuleList *rules;
    size_t i = 0;

    hmp_warn_acl();

    if (!auth) {
        return;
    }

    monitor_printf(mon, "policy: %s\n",
                   QAuthZListPolicy_str(auth->policy));

    rules = auth->rules;
    while (rules) {
        QAuthZListRule *rule = rules->value;
        i++;
        monitor_printf(mon, "%zu: %s %s\n", i,
                       QAuthZListPolicy_str(rule->policy),
                       rule->match);
        rules = rules->next;
    }
}

static void hmp_acl_reset(Monitor *mon, const QDict *qdict)
{
    const char *aclname = qdict_get_str(qdict, "aclname");
    QAuthZList *auth = find_auth(mon, aclname);

    hmp_warn_acl();

    if (!auth) {
        return;
    }

    auth->policy = QAUTHZ_LIST_POLICY_DENY;
    qapi_free_QAuthZListRuleList(auth->rules);
    auth->rules = NULL;
    monitor_printf(mon, "acl: removed all rules\n");
}

static void hmp_acl_policy(Monitor *mon, const QDict *qdict)
{
    const char *aclname = qdict_get_str(qdict, "aclname");
    const char *policy = qdict_get_str(qdict, "policy");
    QAuthZList *auth = find_auth(mon, aclname);
    int val;
    Error *err = NULL;

    hmp_warn_acl();

    if (!auth) {
        return;
    }

    val = qapi_enum_parse(&QAuthZListPolicy_lookup,
                          policy,
                          QAUTHZ_LIST_POLICY_DENY,
                          &err);
    if (err) {
        error_free(err);
        monitor_printf(mon, "acl: unknown policy '%s', "
                       "expected 'deny' or 'allow'\n", policy);
    } else {
        auth->policy = val;
        if (auth->policy == QAUTHZ_LIST_POLICY_ALLOW) {
            monitor_printf(mon, "acl: policy set to 'allow'\n");
        } else {
            monitor_printf(mon, "acl: policy set to 'deny'\n");
        }
    }
}

static QAuthZListFormat hmp_acl_get_format(const char *match)
{
    if (strchr(match, '*')) {
        return QAUTHZ_LIST_FORMAT_GLOB;
    } else {
        return QAUTHZ_LIST_FORMAT_EXACT;
    }
}

static void hmp_acl_add(Monitor *mon, const QDict *qdict)
{
    const char *aclname = qdict_get_str(qdict, "aclname");
    const char *match = qdict_get_str(qdict, "match");
    const char *policystr = qdict_get_str(qdict, "policy");
    int has_index = qdict_haskey(qdict, "index");
    int index = qdict_get_try_int(qdict, "index", -1);
    QAuthZList *auth = find_auth(mon, aclname);
    Error *err = NULL;
    QAuthZListPolicy policy;
    QAuthZListFormat format;
    size_t i = 0;

    hmp_warn_acl();

    if (!auth) {
        return;
    }

    policy = qapi_enum_parse(&QAuthZListPolicy_lookup,
                             policystr,
                             QAUTHZ_LIST_POLICY_DENY,
                             &err);
    if (err) {
        error_free(err);
        monitor_printf(mon, "acl: unknown policy '%s', "
                       "expected 'deny' or 'allow'\n", policystr);
        return;
    }

    format = hmp_acl_get_format(match);

    if (has_index && index == 0) {
        monitor_printf(mon, "acl: unable to add acl entry\n");
        return;
    }

    if (has_index) {
        i = qauthz_list_insert_rule(auth, match, policy,
                                    format, index - 1, &err);
    } else {
        i = qauthz_list_append_rule(auth, match, policy,
                                    format, &err);
    }
    if (err) {
        monitor_printf(mon, "acl: unable to add rule: %s",
                       error_get_pretty(err));
        error_free(err);
    } else {
        monitor_printf(mon, "acl: added rule at position %zu\n", i + 1);
    }
}

static void hmp_acl_remove(Monitor *mon, const QDict *qdict)
{
    const char *aclname = qdict_get_str(qdict, "aclname");
    const char *match = qdict_get_str(qdict, "match");
    QAuthZList *auth = find_auth(mon, aclname);
    ssize_t i = 0;

    hmp_warn_acl();

    if (!auth) {
        return;
    }

    i = qauthz_list_delete_rule(auth, match);
    if (i >= 0) {
        monitor_printf(mon, "acl: removed rule at position %zu\n", i + 1);
    } else {
        monitor_printf(mon, "acl: no matching acl entry\n");
    }
}

void qmp_getfd(const char *fdname, Error **errp)
{
    mon_fd_t *monfd;
    int fd, tmp_fd;

    fd = qemu_chr_fe_get_msgfd(&cur_mon->chr);
    if (fd == -1) {
        error_setg(errp, QERR_FD_NOT_SUPPLIED);
        return;
    }

    if (qemu_isdigit(fdname[0])) {
        close(fd);
        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "fdname",
                   "a name not starting with a digit");
        return;
    }

    qemu_mutex_lock(&cur_mon->mon_lock);
    QLIST_FOREACH(monfd, &cur_mon->fds, next) {
        if (strcmp(monfd->name, fdname) != 0) {
            continue;
        }

        tmp_fd = monfd->fd;
        monfd->fd = fd;
        qemu_mutex_unlock(&cur_mon->mon_lock);
        /* Make sure close() is outside critical section */
        close(tmp_fd);
        return;
    }

    monfd = g_malloc0(sizeof(mon_fd_t));
    monfd->name = g_strdup(fdname);
    monfd->fd = fd;

    QLIST_INSERT_HEAD(&cur_mon->fds, monfd, next);
    qemu_mutex_unlock(&cur_mon->mon_lock);
}

void qmp_closefd(const char *fdname, Error **errp)
{
    mon_fd_t *monfd;
    int tmp_fd;

    qemu_mutex_lock(&cur_mon->mon_lock);
    QLIST_FOREACH(monfd, &cur_mon->fds, next) {
        if (strcmp(monfd->name, fdname) != 0) {
            continue;
        }

        QLIST_REMOVE(monfd, next);
        tmp_fd = monfd->fd;
        g_free(monfd->name);
        g_free(monfd);
        qemu_mutex_unlock(&cur_mon->mon_lock);
        /* Make sure close() is outside critical section */
        close(tmp_fd);
        return;
    }

    qemu_mutex_unlock(&cur_mon->mon_lock);
    error_setg(errp, QERR_FD_NOT_FOUND, fdname);
}

int monitor_get_fd(Monitor *mon, const char *fdname, Error **errp)
{
    mon_fd_t *monfd;

    qemu_mutex_lock(&mon->mon_lock);
    QLIST_FOREACH(monfd, &mon->fds, next) {
        int fd;

        if (strcmp(monfd->name, fdname) != 0) {
            continue;
        }

        fd = monfd->fd;

        /* caller takes ownership of fd */
        QLIST_REMOVE(monfd, next);
        g_free(monfd->name);
        g_free(monfd);
        qemu_mutex_unlock(&mon->mon_lock);

        return fd;
    }

    qemu_mutex_unlock(&mon->mon_lock);
    error_setg(errp, "File descriptor named '%s' has not been found", fdname);
    return -1;
}

static void monitor_fdset_cleanup(MonFdset *mon_fdset)
{
    MonFdsetFd *mon_fdset_fd;
    MonFdsetFd *mon_fdset_fd_next;

    QLIST_FOREACH_SAFE(mon_fdset_fd, &mon_fdset->fds, next, mon_fdset_fd_next) {
        if ((mon_fdset_fd->removed ||
                (QLIST_EMPTY(&mon_fdset->dup_fds) && mon_refcount == 0)) &&
                runstate_is_running()) {
            close(mon_fdset_fd->fd);
            g_free(mon_fdset_fd->opaque);
            QLIST_REMOVE(mon_fdset_fd, next);
            g_free(mon_fdset_fd);
        }
    }

    if (QLIST_EMPTY(&mon_fdset->fds) && QLIST_EMPTY(&mon_fdset->dup_fds)) {
        QLIST_REMOVE(mon_fdset, next);
        g_free(mon_fdset);
    }
}

static void monitor_fdsets_cleanup(void)
{
    MonFdset *mon_fdset;
    MonFdset *mon_fdset_next;

    qemu_mutex_lock(&mon_fdsets_lock);
    QLIST_FOREACH_SAFE(mon_fdset, &mon_fdsets, next, mon_fdset_next) {
        monitor_fdset_cleanup(mon_fdset);
    }
    qemu_mutex_unlock(&mon_fdsets_lock);
}

AddfdInfo *qmp_add_fd(bool has_fdset_id, int64_t fdset_id, bool has_opaque,
                      const char *opaque, Error **errp)
{
    int fd;
    Monitor *mon = cur_mon;
    AddfdInfo *fdinfo;

    fd = qemu_chr_fe_get_msgfd(&mon->chr);
    if (fd == -1) {
        error_setg(errp, QERR_FD_NOT_SUPPLIED);
        goto error;
    }

    fdinfo = monitor_fdset_add_fd(fd, has_fdset_id, fdset_id,
                                  has_opaque, opaque, errp);
    if (fdinfo) {
        return fdinfo;
    }

error:
    if (fd != -1) {
        close(fd);
    }
    return NULL;
}

void qmp_remove_fd(int64_t fdset_id, bool has_fd, int64_t fd, Error **errp)
{
    MonFdset *mon_fdset;
    MonFdsetFd *mon_fdset_fd;
    char fd_str[60];

    qemu_mutex_lock(&mon_fdsets_lock);
    QLIST_FOREACH(mon_fdset, &mon_fdsets, next) {
        if (mon_fdset->id != fdset_id) {
            continue;
        }
        QLIST_FOREACH(mon_fdset_fd, &mon_fdset->fds, next) {
            if (has_fd) {
                if (mon_fdset_fd->fd != fd) {
                    continue;
                }
                mon_fdset_fd->removed = true;
                break;
            } else {
                mon_fdset_fd->removed = true;
            }
        }
        if (has_fd && !mon_fdset_fd) {
            goto error;
        }
        monitor_fdset_cleanup(mon_fdset);
        qemu_mutex_unlock(&mon_fdsets_lock);
        return;
    }

error:
    qemu_mutex_unlock(&mon_fdsets_lock);
    if (has_fd) {
        snprintf(fd_str, sizeof(fd_str), "fdset-id:%" PRId64 ", fd:%" PRId64,
                 fdset_id, fd);
    } else {
        snprintf(fd_str, sizeof(fd_str), "fdset-id:%" PRId64, fdset_id);
    }
    error_setg(errp, QERR_FD_NOT_FOUND, fd_str);
}

FdsetInfoList *qmp_query_fdsets(Error **errp)
{
    MonFdset *mon_fdset;
    MonFdsetFd *mon_fdset_fd;
    FdsetInfoList *fdset_list = NULL;

    qemu_mutex_lock(&mon_fdsets_lock);
    QLIST_FOREACH(mon_fdset, &mon_fdsets, next) {
        FdsetInfoList *fdset_info = g_malloc0(sizeof(*fdset_info));
        FdsetFdInfoList *fdsetfd_list = NULL;

        fdset_info->value = g_malloc0(sizeof(*fdset_info->value));
        fdset_info->value->fdset_id = mon_fdset->id;

        QLIST_FOREACH(mon_fdset_fd, &mon_fdset->fds, next) {
            FdsetFdInfoList *fdsetfd_info;

            fdsetfd_info = g_malloc0(sizeof(*fdsetfd_info));
            fdsetfd_info->value = g_malloc0(sizeof(*fdsetfd_info->value));
            fdsetfd_info->value->fd = mon_fdset_fd->fd;
            if (mon_fdset_fd->opaque) {
                fdsetfd_info->value->has_opaque = true;
                fdsetfd_info->value->opaque = g_strdup(mon_fdset_fd->opaque);
            } else {
                fdsetfd_info->value->has_opaque = false;
            }

            fdsetfd_info->next = fdsetfd_list;
            fdsetfd_list = fdsetfd_info;
        }

        fdset_info->value->fds = fdsetfd_list;

        fdset_info->next = fdset_list;
        fdset_list = fdset_info;
    }
    qemu_mutex_unlock(&mon_fdsets_lock);

    return fdset_list;
}

AddfdInfo *monitor_fdset_add_fd(int fd, bool has_fdset_id, int64_t fdset_id,
                                bool has_opaque, const char *opaque,
                                Error **errp)
{
    MonFdset *mon_fdset = NULL;
    MonFdsetFd *mon_fdset_fd;
    AddfdInfo *fdinfo;

    qemu_mutex_lock(&mon_fdsets_lock);
    if (has_fdset_id) {
        QLIST_FOREACH(mon_fdset, &mon_fdsets, next) {
            /* Break if match found or match impossible due to ordering by ID */
            if (fdset_id <= mon_fdset->id) {
                if (fdset_id < mon_fdset->id) {
                    mon_fdset = NULL;
                }
                break;
            }
        }
    }

    if (mon_fdset == NULL) {
        int64_t fdset_id_prev = -1;
        MonFdset *mon_fdset_cur = QLIST_FIRST(&mon_fdsets);

        if (has_fdset_id) {
            if (fdset_id < 0) {
                error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "fdset-id",
                           "a non-negative value");
                qemu_mutex_unlock(&mon_fdsets_lock);
                return NULL;
            }
            /* Use specified fdset ID */
            QLIST_FOREACH(mon_fdset, &mon_fdsets, next) {
                mon_fdset_cur = mon_fdset;
                if (fdset_id < mon_fdset_cur->id) {
                    break;
                }
            }
        } else {
            /* Use first available fdset ID */
            QLIST_FOREACH(mon_fdset, &mon_fdsets, next) {
                mon_fdset_cur = mon_fdset;
                if (fdset_id_prev == mon_fdset_cur->id - 1) {
                    fdset_id_prev = mon_fdset_cur->id;
                    continue;
                }
                break;
            }
        }

        mon_fdset = g_malloc0(sizeof(*mon_fdset));
        if (has_fdset_id) {
            mon_fdset->id = fdset_id;
        } else {
            mon_fdset->id = fdset_id_prev + 1;
        }

        /* The fdset list is ordered by fdset ID */
        if (!mon_fdset_cur) {
            QLIST_INSERT_HEAD(&mon_fdsets, mon_fdset, next);
        } else if (mon_fdset->id < mon_fdset_cur->id) {
            QLIST_INSERT_BEFORE(mon_fdset_cur, mon_fdset, next);
        } else {
            QLIST_INSERT_AFTER(mon_fdset_cur, mon_fdset, next);
        }
    }

    mon_fdset_fd = g_malloc0(sizeof(*mon_fdset_fd));
    mon_fdset_fd->fd = fd;
    mon_fdset_fd->removed = false;
    if (has_opaque) {
        mon_fdset_fd->opaque = g_strdup(opaque);
    }
    QLIST_INSERT_HEAD(&mon_fdset->fds, mon_fdset_fd, next);

    fdinfo = g_malloc0(sizeof(*fdinfo));
    fdinfo->fdset_id = mon_fdset->id;
    fdinfo->fd = mon_fdset_fd->fd;

    qemu_mutex_unlock(&mon_fdsets_lock);
    return fdinfo;
}

int monitor_fdset_get_fd(int64_t fdset_id, int flags)
{
#ifdef _WIN32
    return -ENOENT;
#else
    MonFdset *mon_fdset;
    MonFdsetFd *mon_fdset_fd;
    int mon_fd_flags;
    int ret;

    qemu_mutex_lock(&mon_fdsets_lock);
    QLIST_FOREACH(mon_fdset, &mon_fdsets, next) {
        if (mon_fdset->id != fdset_id) {
            continue;
        }
        QLIST_FOREACH(mon_fdset_fd, &mon_fdset->fds, next) {
            mon_fd_flags = fcntl(mon_fdset_fd->fd, F_GETFL);
            if (mon_fd_flags == -1) {
                ret = -errno;
                goto out;
            }

            if ((flags & O_ACCMODE) == (mon_fd_flags & O_ACCMODE)) {
                ret = mon_fdset_fd->fd;
                goto out;
            }
        }
        ret = -EACCES;
        goto out;
    }
    ret = -ENOENT;

out:
    qemu_mutex_unlock(&mon_fdsets_lock);
    return ret;
#endif
}

int monitor_fdset_dup_fd_add(int64_t fdset_id, int dup_fd)
{
    MonFdset *mon_fdset;
    MonFdsetFd *mon_fdset_fd_dup;

    qemu_mutex_lock(&mon_fdsets_lock);
    QLIST_FOREACH(mon_fdset, &mon_fdsets, next) {
        if (mon_fdset->id != fdset_id) {
            continue;
        }
        QLIST_FOREACH(mon_fdset_fd_dup, &mon_fdset->dup_fds, next) {
            if (mon_fdset_fd_dup->fd == dup_fd) {
                goto err;
            }
        }
        mon_fdset_fd_dup = g_malloc0(sizeof(*mon_fdset_fd_dup));
        mon_fdset_fd_dup->fd = dup_fd;
        QLIST_INSERT_HEAD(&mon_fdset->dup_fds, mon_fdset_fd_dup, next);
        qemu_mutex_unlock(&mon_fdsets_lock);
        return 0;
    }

err:
    qemu_mutex_unlock(&mon_fdsets_lock);
    return -1;
}

static int64_t monitor_fdset_dup_fd_find_remove(int dup_fd, bool remove)
{
    MonFdset *mon_fdset;
    MonFdsetFd *mon_fdset_fd_dup;

    qemu_mutex_lock(&mon_fdsets_lock);
    QLIST_FOREACH(mon_fdset, &mon_fdsets, next) {
        QLIST_FOREACH(mon_fdset_fd_dup, &mon_fdset->dup_fds, next) {
            if (mon_fdset_fd_dup->fd == dup_fd) {
                if (remove) {
                    QLIST_REMOVE(mon_fdset_fd_dup, next);
                    if (QLIST_EMPTY(&mon_fdset->dup_fds)) {
                        monitor_fdset_cleanup(mon_fdset);
                    }
                    goto err;
                } else {
                    qemu_mutex_unlock(&mon_fdsets_lock);
                    return mon_fdset->id;
                }
            }
        }
    }

err:
    qemu_mutex_unlock(&mon_fdsets_lock);
    return -1;
}

int64_t monitor_fdset_dup_fd_find(int dup_fd)
{
    return monitor_fdset_dup_fd_find_remove(dup_fd, false);
}

void monitor_fdset_dup_fd_remove(int dup_fd)
{
    monitor_fdset_dup_fd_find_remove(dup_fd, true);
}

int monitor_fd_param(Monitor *mon, const char *fdname, Error **errp)
{
    int fd;
    Error *local_err = NULL;

    if (!qemu_isdigit(fdname[0]) && mon) {
        fd = monitor_get_fd(mon, fdname, &local_err);
    } else {
        fd = qemu_parse_fd(fdname);
        if (fd == -1) {
            error_setg(&local_err, "Invalid file descriptor number '%s'",
                       fdname);
        }
    }
    if (local_err) {
        error_propagate(errp, local_err);
        assert(fd == -1);
    } else {
        assert(fd != -1);
    }

    return fd;
}

/* Please update hmp-commands.hx when adding or changing commands */
static mon_cmd_t info_cmds[] = {
#include "hmp-commands-info.h"
    { NULL, NULL, },
};

/* mon_cmds and info_cmds would be sorted at runtime */
static mon_cmd_t mon_cmds[] = {
#include "hmp-commands.h"
    { NULL, NULL, },
};

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

static const char *pch;
static sigjmp_buf expr_env;


static void GCC_FMT_ATTR(2, 3) QEMU_NORETURN
expr_error(Monitor *mon, const char *fmt, ...)
{
    va_list ap;
    va_start(ap, fmt);
    monitor_vprintf(mon, fmt, ap);
    monitor_printf(mon, "\n");
    va_end(ap);
    siglongjmp(expr_env, 1);
}

/* return 0 if OK, -1 if not found */
static int get_monitor_def(target_long *pval, const char *name)
{
    const MonitorDef *md = target_monitor_defs();
    CPUState *cs = mon_get_cpu();
    void *ptr;
    uint64_t tmp = 0;
    int ret;

    if (cs == NULL || md == NULL) {
        return -1;
    }

    for(; md->name != NULL; md++) {
        if (compare_cmd(name, md->name)) {
            if (md->get_value) {
                *pval = md->get_value(md, md->offset);
            } else {
                CPUArchState *env = mon_get_cpu_env();
                ptr = (uint8_t *)env + md->offset;
                switch(md->type) {
                case MD_I32:
                    *pval = *(int32_t *)ptr;
                    break;
                case MD_TLONG:
                    *pval = *(target_long *)ptr;
                    break;
                default:
                    *pval = 0;
                    break;
                }
            }
            return 0;
        }
    }

    ret = target_get_monitor_def(cs, name, &tmp);
    if (!ret) {
        *pval = (target_long) tmp;
    }

    return ret;
}

static void next(void)
{
    if (*pch != '\0') {
        pch++;
        while (qemu_isspace(*pch))
            pch++;
    }
}

static int64_t expr_sum(Monitor *mon);

static int64_t expr_unary(Monitor *mon)
{
    int64_t n;
    char *p;
    int ret;

    switch(*pch) {
    case '+':
        next();
        n = expr_unary(mon);
        break;
    case '-':
        next();
        n = -expr_unary(mon);
        break;
    case '~':
        next();
        n = ~expr_unary(mon);
        break;
    case '(':
        next();
        n = expr_sum(mon);
        if (*pch != ')') {
            expr_error(mon, "')' expected");
        }
        next();
        break;
    case '\'':
        pch++;
        if (*pch == '\0')
            expr_error(mon, "character constant expected");
        n = *pch;
        pch++;
        if (*pch != '\'')
            expr_error(mon, "missing terminating \' character");
        next();
        break;
    case '$':
        {
            char buf[128], *q;
            target_long reg=0;

            pch++;
            q = buf;
            while ((*pch >= 'a' && *pch <= 'z') ||
                   (*pch >= 'A' && *pch <= 'Z') ||
                   (*pch >= '0' && *pch <= '9') ||
                   *pch == '_' || *pch == '.') {
                if ((q - buf) < sizeof(buf) - 1)
                    *q++ = *pch;
                pch++;
            }
            while (qemu_isspace(*pch))
                pch++;
            *q = 0;
            ret = get_monitor_def(&reg, buf);
            if (ret < 0)
                expr_error(mon, "unknown register");
            n = reg;
        }
        break;
    case '\0':
        expr_error(mon, "unexpected end of expression");
        n = 0;
        break;
    default:
        errno = 0;
        n = strtoull(pch, &p, 0);
        if (errno == ERANGE) {
            expr_error(mon, "number too large");
        }
        if (pch == p) {
            expr_error(mon, "invalid char '%c' in expression", *p);
        }
        pch = p;
        while (qemu_isspace(*pch))
            pch++;
        break;
    }
    return n;
}


static int64_t expr_prod(Monitor *mon)
{
    int64_t val, val2;
    int op;

    val = expr_unary(mon);
    for(;;) {
        op = *pch;
        if (op != '*' && op != '/' && op != '%')
            break;
        next();
        val2 = expr_unary(mon);
        switch(op) {
        default:
        case '*':
            val *= val2;
            break;
        case '/':
        case '%':
            if (val2 == 0)
                expr_error(mon, "division by zero");
            if (op == '/')
                val /= val2;
            else
                val %= val2;
            break;
        }
    }
    return val;
}

static int64_t expr_logic(Monitor *mon)
{
    int64_t val, val2;
    int op;

    val = expr_prod(mon);
    for(;;) {
        op = *pch;
        if (op != '&' && op != '|' && op != '^')
            break;
        next();
        val2 = expr_prod(mon);
        switch(op) {
        default:
        case '&':
            val &= val2;
            break;
        case '|':
            val |= val2;
            break;
        case '^':
            val ^= val2;
            break;
        }
    }
    return val;
}

static int64_t expr_sum(Monitor *mon)
{
    int64_t val, val2;
    int op;

    val = expr_logic(mon);
    for(;;) {
        op = *pch;
        if (op != '+' && op != '-')
            break;
        next();
        val2 = expr_logic(mon);
        if (op == '+')
            val += val2;
        else
            val -= val2;
    }
    return val;
}

static int get_expr(Monitor *mon, int64_t *pval, const char **pp)
{
    pch = *pp;
    if (sigsetjmp(expr_env, 0)) {
        *pp = pch;
        return -1;
    }
    while (qemu_isspace(*pch))
        pch++;
    *pval = expr_sum(mon);
    *pp = pch;
    return 0;
}

static int get_double(Monitor *mon, double *pval, const char **pp)
{
    const char *p = *pp;
    char *tailp;
    double d;

    d = strtod(p, &tailp);
    if (tailp == p) {
        monitor_printf(mon, "Number expected\n");
        return -1;
    }
    if (d != d || d - d != 0) {
        /* NaN or infinity */
        monitor_printf(mon, "Bad number\n");
        return -1;
    }
    *pval = d;
    *pp = tailp;
    return 0;
}

/*
 * Store the command-name in cmdname, and return a pointer to
 * the remaining of the command string.
 */
static const char *get_command_name(const char *cmdline,
                                    char *cmdname, size_t nlen)
{
    size_t len;
    const char *p, *pstart;

    p = cmdline;
    while (qemu_isspace(*p))
        p++;
    if (*p == '\0')
        return NULL;
    pstart = p;
    while (*p != '\0' && *p != '/' && !qemu_isspace(*p))
        p++;
    len = p - pstart;
    if (len > nlen - 1)
        len = nlen - 1;
    memcpy(cmdname, pstart, len);
    cmdname[len] = '\0';
    return p;
}

/**
 * Read key of 'type' into 'key' and return the current
 * 'type' pointer.
 */
static char *key_get_info(const char *type, char **key)
{
    size_t len;
    char *p, *str;

    if (*type == ',')
        type++;

    p = strchr(type, ':');
    if (!p) {
        *key = NULL;
        return NULL;
    }
    len = p - type;

    str = g_malloc(len + 1);
    memcpy(str, type, len);
    str[len] = '\0';

    *key = str;
    return ++p;
}

static int default_fmt_format = 'x';
static int default_fmt_size = 4;

static int is_valid_option(const char *c, const char *typestr)
{
    char option[3];
  
    option[0] = '-';
    option[1] = *c;
    option[2] = '\0';
  
    typestr = strstr(typestr, option);
    return (typestr != NULL);
}

static const mon_cmd_t *search_dispatch_table(const mon_cmd_t *disp_table,
                                              const char *cmdname)
{
    const mon_cmd_t *cmd;

    for (cmd = disp_table; cmd->name != NULL; cmd++) {
        if (compare_cmd(cmdname, cmd->name)) {
            return cmd;
        }
    }

    return NULL;
}

/*
 * Parse command name from @cmdp according to command table @table.
 * If blank, return NULL.
 * Else, if no valid command can be found, report to @mon, and return
 * NULL.
 * Else, change @cmdp to point right behind the name, and return its
 * command table entry.
 * Do not assume the return value points into @table!  It doesn't when
 * the command is found in a sub-command table.
 */
static const mon_cmd_t *monitor_parse_command(Monitor *mon,
                                              const char *cmdp_start,
                                              const char **cmdp,
                                              mon_cmd_t *table)
{
    const char *p;
    const mon_cmd_t *cmd;
    char cmdname[256];

    /* extract the command name */
    p = get_command_name(*cmdp, cmdname, sizeof(cmdname));
    if (!p)
        return NULL;

    cmd = search_dispatch_table(table, cmdname);
    if (!cmd) {
        monitor_printf(mon, "unknown command: '%.*s'\n",
                       (int)(p - cmdp_start), cmdp_start);
        return NULL;
    }
    if (runstate_check(RUN_STATE_PRECONFIG) && !cmd_can_preconfig(cmd)) {
        monitor_printf(mon, "Command '%.*s' not available with -preconfig "
                            "until after exit_preconfig.\n",
                       (int)(p - cmdp_start), cmdp_start);
        return NULL;
    }

    /* filter out following useless space */
    while (qemu_isspace(*p)) {
        p++;
    }

    *cmdp = p;
    /* search sub command */
    if (cmd->sub_table != NULL && *p != '\0') {
        return monitor_parse_command(mon, cmdp_start, cmdp, cmd->sub_table);
    }

    return cmd;
}

/*
 * Parse arguments for @cmd.
 * If it can't be parsed, report to @mon, and return NULL.
 * Else, insert command arguments into a QDict, and return it.
 * Note: On success, caller has to free the QDict structure.
 */

static QDict *monitor_parse_arguments(Monitor *mon,
                                      const char **endp,
                                      const mon_cmd_t *cmd)
{
    const char *typestr;
    char *key;
    int c;
    const char *p = *endp;
    char buf[1024];
    QDict *qdict = qdict_new();

    /* parse the parameters */
    typestr = cmd->args_type;
    for(;;) {
        typestr = key_get_info(typestr, &key);
        if (!typestr)
            break;
        c = *typestr;
        typestr++;
        switch(c) {
        case 'F':
        case 'B':
        case 's':
            {
                int ret;

                while (qemu_isspace(*p))
                    p++;
                if (*typestr == '?') {
                    typestr++;
                    if (*p == '\0') {
                        /* no optional string: NULL argument */
                        break;
                    }
                }
                ret = get_str(buf, sizeof(buf), &p);
                if (ret < 0) {
                    switch(c) {
                    case 'F':
                        monitor_printf(mon, "%s: filename expected\n",
                                       cmd->name);
                        break;
                    case 'B':
                        monitor_printf(mon, "%s: block device name expected\n",
                                       cmd->name);
                        break;
                    default:
                        monitor_printf(mon, "%s: string expected\n", cmd->name);
                        break;
                    }
                    goto fail;
                }
                qdict_put_str(qdict, key, buf);
            }
            break;
        case 'O':
            {
                QemuOptsList *opts_list;
                QemuOpts *opts;

                opts_list = qemu_find_opts(key);
                if (!opts_list || opts_list->desc->name) {
                    goto bad_type;
                }
                while (qemu_isspace(*p)) {
                    p++;
                }
                if (!*p)
                    break;
                if (get_str(buf, sizeof(buf), &p) < 0) {
                    goto fail;
                }
                opts = qemu_opts_parse_noisily(opts_list, buf, true);
                if (!opts) {
                    goto fail;
                }
                qemu_opts_to_qdict(opts, qdict);
                qemu_opts_del(opts);
            }
            break;
        case '/':
            {
                int count, format, size;

                while (qemu_isspace(*p))
                    p++;
                if (*p == '/') {
                    /* format found */
                    p++;
                    count = 1;
                    if (qemu_isdigit(*p)) {
                        count = 0;
                        while (qemu_isdigit(*p)) {
                            count = count * 10 + (*p - '0');
                            p++;
                        }
                    }
                    size = -1;
                    format = -1;
                    for(;;) {
                        switch(*p) {
                        case 'o':
                        case 'd':
                        case 'u':
                        case 'x':
                        case 'i':
                        case 'c':
                            format = *p++;
                            break;
                        case 'b':
                            size = 1;
                            p++;
                            break;
                        case 'h':
                            size = 2;
                            p++;
                            break;
                        case 'w':
                            size = 4;
                            p++;
                            break;
                        case 'g':
                        case 'L':
                            size = 8;
                            p++;
                            break;
                        default:
                            goto next;
                        }
                    }
                next:
                    if (*p != '\0' && !qemu_isspace(*p)) {
                        monitor_printf(mon, "invalid char in format: '%c'\n",
                                       *p);
                        goto fail;
                    }
                    if (format < 0)
                        format = default_fmt_format;
                    if (format != 'i') {
                        /* for 'i', not specifying a size gives -1 as size */
                        if (size < 0)
                            size = default_fmt_size;
                        default_fmt_size = size;
                    }
                    default_fmt_format = format;
                } else {
                    count = 1;
                    format = default_fmt_format;
                    if (format != 'i') {
                        size = default_fmt_size;
                    } else {
                        size = -1;
                    }
                }
                qdict_put_int(qdict, "count", count);
                qdict_put_int(qdict, "format", format);
                qdict_put_int(qdict, "size", size);
            }
            break;
        case 'i':
        case 'l':
        case 'M':
            {
                int64_t val;

                while (qemu_isspace(*p))
                    p++;
                if (*typestr == '?' || *typestr == '.') {
                    if (*typestr == '?') {
                        if (*p == '\0') {
                            typestr++;
                            break;
                        }
                    } else {
                        if (*p == '.') {
                            p++;
                            while (qemu_isspace(*p))
                                p++;
                        } else {
                            typestr++;
                            break;
                        }
                    }
                    typestr++;
                }
                if (get_expr(mon, &val, &p))
                    goto fail;
                /* Check if 'i' is greater than 32-bit */
                if ((c == 'i') && ((val >> 32) & 0xffffffff)) {
                    monitor_printf(mon, "\'%s\' has failed: ", cmd->name);
                    monitor_printf(mon, "integer is for 32-bit values\n");
                    goto fail;
                } else if (c == 'M') {
                    if (val < 0) {
                        monitor_printf(mon, "enter a positive value\n");
                        goto fail;
                    }
                    val *= MiB;
                }
                qdict_put_int(qdict, key, val);
            }
            break;
        case 'o':
            {
                int ret;
                uint64_t val;
                const char *end;

                while (qemu_isspace(*p)) {
                    p++;
                }
                if (*typestr == '?') {
                    typestr++;
                    if (*p == '\0') {
                        break;
                    }
                }
                ret = qemu_strtosz_MiB(p, &end, &val);
                if (ret < 0 || val > INT64_MAX) {
                    monitor_printf(mon, "invalid size\n");
                    goto fail;
                }
                qdict_put_int(qdict, key, val);
                p = end;
            }
            break;
        case 'T':
            {
                double val;

                while (qemu_isspace(*p))
                    p++;
                if (*typestr == '?') {
                    typestr++;
                    if (*p == '\0') {
                        break;
                    }
                }
                if (get_double(mon, &val, &p) < 0) {
                    goto fail;
                }
                if (p[0] && p[1] == 's') {
                    switch (*p) {
                    case 'm':
                        val /= 1e3; p += 2; break;
                    case 'u':
                        val /= 1e6; p += 2; break;
                    case 'n':
                        val /= 1e9; p += 2; break;
                    }
                }
                if (*p && !qemu_isspace(*p)) {
                    monitor_printf(mon, "Unknown unit suffix\n");
                    goto fail;
                }
                qdict_put(qdict, key, qnum_from_double(val));
            }
            break;
        case 'b':
            {
                const char *beg;
                bool val;

                while (qemu_isspace(*p)) {
                    p++;
                }
                beg = p;
                while (qemu_isgraph(*p)) {
                    p++;
                }
                if (p - beg == 2 && !memcmp(beg, "on", p - beg)) {
                    val = true;
                } else if (p - beg == 3 && !memcmp(beg, "off", p - beg)) {
                    val = false;
                } else {
                    monitor_printf(mon, "Expected 'on' or 'off'\n");
                    goto fail;
                }
                qdict_put_bool(qdict, key, val);
            }
            break;
        case '-':
            {
                const char *tmp = p;
                int skip_key = 0;
                /* option */

                c = *typestr++;
                if (c == '\0')
                    goto bad_type;
                while (qemu_isspace(*p))
                    p++;
                if (*p == '-') {
                    p++;
                    if(c != *p) {
                        if(!is_valid_option(p, typestr)) {
                  
                            monitor_printf(mon, "%s: unsupported option -%c\n",
                                           cmd->name, *p);
                            goto fail;
                        } else {
                            skip_key = 1;
                        }
                    }
                    if(skip_key) {
                        p = tmp;
                    } else {
                        /* has option */
                        p++;
                        qdict_put_bool(qdict, key, true);
                    }
                }
            }
            break;
        case 'S':
            {
                /* package all remaining string */
                int len;

                while (qemu_isspace(*p)) {
                    p++;
                }
                if (*typestr == '?') {
                    typestr++;
                    if (*p == '\0') {
                        /* no remaining string: NULL argument */
                        break;
                    }
                }
                len = strlen(p);
                if (len <= 0) {
                    monitor_printf(mon, "%s: string expected\n",
                                   cmd->name);
                    goto fail;
                }
                qdict_put_str(qdict, key, p);
                p += len;
            }
            break;
        default:
        bad_type:
            monitor_printf(mon, "%s: unknown type '%c'\n", cmd->name, c);
            goto fail;
        }
        g_free(key);
        key = NULL;
    }
    /* check that all arguments were parsed */
    while (qemu_isspace(*p))
        p++;
    if (*p != '\0') {
        monitor_printf(mon, "%s: extraneous characters at the end of line\n",
                       cmd->name);
        goto fail;
    }

    return qdict;

fail:
    qobject_unref(qdict);
    g_free(key);
    return NULL;
}

static void handle_hmp_command(Monitor *mon, const char *cmdline)
{
    QDict *qdict;
    const mon_cmd_t *cmd;
    const char *cmd_start = cmdline;

    trace_handle_hmp_command(mon, cmdline);

    cmd = monitor_parse_command(mon, cmdline, &cmdline, mon->cmd_table);
    if (!cmd) {
        return;
    }

    qdict = monitor_parse_arguments(mon, &cmdline, cmd);
    if (!qdict) {
        while (cmdline > cmd_start && qemu_isspace(cmdline[-1])) {
            cmdline--;
        }
        monitor_printf(mon, "Try \"help %.*s\" for more information\n",
                       (int)(cmdline - cmd_start), cmd_start);
        return;
    }

    cmd->cmd(mon, qdict);
    qobject_unref(qdict);
}

static void cmd_completion(Monitor *mon, const char *name, const char *list)
{
    const char *p, *pstart;
    char cmd[128];
    int len;

    p = list;
    for(;;) {
        pstart = p;
        p = qemu_strchrnul(p, '|');
        len = p - pstart;
        if (len > sizeof(cmd) - 2)
            len = sizeof(cmd) - 2;
        memcpy(cmd, pstart, len);
        cmd[len] = '\0';
        if (name[0] == '\0' || !strncmp(name, cmd, strlen(name))) {
            readline_add_completion(mon->rs, cmd);
        }
        if (*p == '\0')
            break;
        p++;
    }
}

static void file_completion(Monitor *mon, const char *input)
{
    DIR *ffs;
    struct dirent *d;
    char path[1024];
    char file[1024], file_prefix[1024];
    int input_path_len;
    const char *p;

    p = strrchr(input, '/');
    if (!p) {
        input_path_len = 0;
        pstrcpy(file_prefix, sizeof(file_prefix), input);
        pstrcpy(path, sizeof(path), ".");
    } else {
        input_path_len = p - input + 1;
        memcpy(path, input, input_path_len);
        if (input_path_len > sizeof(path) - 1)
            input_path_len = sizeof(path) - 1;
        path[input_path_len] = '\0';
        pstrcpy(file_prefix, sizeof(file_prefix), p + 1);
    }

    ffs = opendir(path);
    if (!ffs)
        return;
    for(;;) {
        struct stat sb;
        d = readdir(ffs);
        if (!d)
            break;

        if (strcmp(d->d_name, ".") == 0 || strcmp(d->d_name, "..") == 0) {
            continue;
        }

        if (strstart(d->d_name, file_prefix, NULL)) {
            memcpy(file, input, input_path_len);
            if (input_path_len < sizeof(file))
                pstrcpy(file + input_path_len, sizeof(file) - input_path_len,
                        d->d_name);
            /* stat the file to find out if it's a directory.
             * In that case add a slash to speed up typing long paths
             */
            if (stat(file, &sb) == 0 && S_ISDIR(sb.st_mode)) {
                pstrcat(file, sizeof(file), "/");
            }
            readline_add_completion(mon->rs, file);
        }
    }
    closedir(ffs);
}

static const char *next_arg_type(const char *typestr)
{
    const char *p = strchr(typestr, ':');
    return (p != NULL ? ++p : typestr);
}

static void add_completion_option(ReadLineState *rs, const char *str,
                                  const char *option)
{
    if (!str || !option) {
        return;
    }
    if (!strncmp(option, str, strlen(str))) {
        readline_add_completion(rs, option);
    }
}

void chardev_add_completion(ReadLineState *rs, int nb_args, const char *str)
{
    size_t len;
    ChardevBackendInfoList *list, *start;

    if (nb_args != 2) {
        return;
    }
    len = strlen(str);
    readline_set_completion_index(rs, len);

    start = list = qmp_query_chardev_backends(NULL);
    while (list) {
        const char *chr_name = list->value->name;

        if (!strncmp(chr_name, str, len)) {
            readline_add_completion(rs, chr_name);
        }
        list = list->next;
    }
    qapi_free_ChardevBackendInfoList(start);
}

void netdev_add_completion(ReadLineState *rs, int nb_args, const char *str)
{
    size_t len;
    int i;

    if (nb_args != 2) {
        return;
    }
    len = strlen(str);
    readline_set_completion_index(rs, len);
    for (i = 0; i < NET_CLIENT_DRIVER__MAX; i++) {
        add_completion_option(rs, str, NetClientDriver_str(i));
    }
}

void device_add_completion(ReadLineState *rs, int nb_args, const char *str)
{
    GSList *list, *elt;
    size_t len;

    if (nb_args != 2) {
        return;
    }

    len = strlen(str);
    readline_set_completion_index(rs, len);
    list = elt = object_class_get_list(TYPE_DEVICE, false);
    while (elt) {
        const char *name;
        DeviceClass *dc = OBJECT_CLASS_CHECK(DeviceClass, elt->data,
                                             TYPE_DEVICE);
        name = object_class_get_name(OBJECT_CLASS(dc));

        if (dc->user_creatable
            && !strncmp(name, str, len)) {
            readline_add_completion(rs, name);
        }
        elt = elt->next;
    }
    g_slist_free(list);
}

void object_add_completion(ReadLineState *rs, int nb_args, const char *str)
{
    GSList *list, *elt;
    size_t len;

    if (nb_args != 2) {
        return;
    }

    len = strlen(str);
    readline_set_completion_index(rs, len);
    list = elt = object_class_get_list(TYPE_USER_CREATABLE, false);
    while (elt) {
        const char *name;

        name = object_class_get_name(OBJECT_CLASS(elt->data));
        if (!strncmp(name, str, len) && strcmp(name, TYPE_USER_CREATABLE)) {
            readline_add_completion(rs, name);
        }
        elt = elt->next;
    }
    g_slist_free(list);
}

static void peripheral_device_del_completion(ReadLineState *rs,
                                             const char *str, size_t len)
{
    Object *peripheral = container_get(qdev_get_machine(), "/peripheral");
    GSList *list, *item;

    list = qdev_build_hotpluggable_device_list(peripheral);
    if (!list) {
        return;
    }

    for (item = list; item; item = g_slist_next(item)) {
        DeviceState *dev = item->data;

        if (dev->id && !strncmp(str, dev->id, len)) {
            readline_add_completion(rs, dev->id);
        }
    }

    g_slist_free(list);
}

void chardev_remove_completion(ReadLineState *rs, int nb_args, const char *str)
{
    size_t len;
    ChardevInfoList *list, *start;

    if (nb_args != 2) {
        return;
    }
    len = strlen(str);
    readline_set_completion_index(rs, len);

    start = list = qmp_query_chardev(NULL);
    while (list) {
        ChardevInfo *chr = list->value;

        if (!strncmp(chr->label, str, len)) {
            readline_add_completion(rs, chr->label);
        }
        list = list->next;
    }
    qapi_free_ChardevInfoList(start);
}

static void ringbuf_completion(ReadLineState *rs, const char *str)
{
    size_t len;
    ChardevInfoList *list, *start;

    len = strlen(str);
    readline_set_completion_index(rs, len);

    start = list = qmp_query_chardev(NULL);
    while (list) {
        ChardevInfo *chr_info = list->value;

        if (!strncmp(chr_info->label, str, len)) {
            Chardev *chr = qemu_chr_find(chr_info->label);
            if (chr && CHARDEV_IS_RINGBUF(chr)) {
                readline_add_completion(rs, chr_info->label);
            }
        }
        list = list->next;
    }
    qapi_free_ChardevInfoList(start);
}

void ringbuf_write_completion(ReadLineState *rs, int nb_args, const char *str)
{
    if (nb_args != 2) {
        return;
    }
    ringbuf_completion(rs, str);
}

void device_del_completion(ReadLineState *rs, int nb_args, const char *str)
{
    size_t len;

    if (nb_args != 2) {
        return;
    }

    len = strlen(str);
    readline_set_completion_index(rs, len);
    peripheral_device_del_completion(rs, str, len);
}

void object_del_completion(ReadLineState *rs, int nb_args, const char *str)
{
    ObjectPropertyInfoList *list, *start;
    size_t len;

    if (nb_args != 2) {
        return;
    }
    len = strlen(str);
    readline_set_completion_index(rs, len);

    start = list = qmp_qom_list("/objects", NULL);
    while (list) {
        ObjectPropertyInfo *info = list->value;

        if (!strncmp(info->type, "child<", 5)
            && !strncmp(info->name, str, len)) {
            readline_add_completion(rs, info->name);
        }
        list = list->next;
    }
    qapi_free_ObjectPropertyInfoList(start);
}

void sendkey_completion(ReadLineState *rs, int nb_args, const char *str)
{
    int i;
    char *sep;
    size_t len;

    if (nb_args != 2) {
        return;
    }
    sep = strrchr(str, '-');
    if (sep) {
        str = sep + 1;
    }
    len = strlen(str);
    readline_set_completion_index(rs, len);
    for (i = 0; i < Q_KEY_CODE__MAX; i++) {
        if (!strncmp(str, QKeyCode_str(i), len)) {
            readline_add_completion(rs, QKeyCode_str(i));
        }
    }
}

void set_link_completion(ReadLineState *rs, int nb_args, const char *str)
{
    size_t len;

    len = strlen(str);
    readline_set_completion_index(rs, len);
    if (nb_args == 2) {
        NetClientState *ncs[MAX_QUEUE_NUM];
        int count, i;
        count = qemu_find_net_clients_except(NULL, ncs,
                                             NET_CLIENT_DRIVER_NONE,
                                             MAX_QUEUE_NUM);
        for (i = 0; i < MIN(count, MAX_QUEUE_NUM); i++) {
            const char *name = ncs[i]->name;
            if (!strncmp(str, name, len)) {
                readline_add_completion(rs, name);
            }
        }
    } else if (nb_args == 3) {
        add_completion_option(rs, str, "on");
        add_completion_option(rs, str, "off");
    }
}

void netdev_del_completion(ReadLineState *rs, int nb_args, const char *str)
{
    int len, count, i;
    NetClientState *ncs[MAX_QUEUE_NUM];

    if (nb_args != 2) {
        return;
    }

    len = strlen(str);
    readline_set_completion_index(rs, len);
    count = qemu_find_net_clients_except(NULL, ncs, NET_CLIENT_DRIVER_NIC,
                                         MAX_QUEUE_NUM);
    for (i = 0; i < MIN(count, MAX_QUEUE_NUM); i++) {
        QemuOpts *opts;
        const char *name = ncs[i]->name;
        if (strncmp(str, name, len)) {
            continue;
        }
        opts = qemu_opts_find(qemu_find_opts_err("netdev", NULL), name);
        if (opts) {
            readline_add_completion(rs, name);
        }
    }
}

void info_trace_events_completion(ReadLineState *rs, int nb_args, const char *str)
{
    size_t len;

    len = strlen(str);
    readline_set_completion_index(rs, len);
    if (nb_args == 2) {
        TraceEventIter iter;
        TraceEvent *ev;
        char *pattern = g_strdup_printf("%s*", str);
        trace_event_iter_init(&iter, pattern);
        while ((ev = trace_event_iter_next(&iter)) != NULL) {
            readline_add_completion(rs, trace_event_get_name(ev));
        }
        g_free(pattern);
    }
}

void trace_event_completion(ReadLineState *rs, int nb_args, const char *str)
{
    size_t len;

    len = strlen(str);
    readline_set_completion_index(rs, len);
    if (nb_args == 2) {
        TraceEventIter iter;
        TraceEvent *ev;
        char *pattern = g_strdup_printf("%s*", str);
        trace_event_iter_init(&iter, pattern);
        while ((ev = trace_event_iter_next(&iter)) != NULL) {
            readline_add_completion(rs, trace_event_get_name(ev));
        }
        g_free(pattern);
    } else if (nb_args == 3) {
        add_completion_option(rs, str, "on");
        add_completion_option(rs, str, "off");
    }
}

void watchdog_action_completion(ReadLineState *rs, int nb_args, const char *str)
{
    int i;

    if (nb_args != 2) {
        return;
    }
    readline_set_completion_index(rs, strlen(str));
    for (i = 0; i < WATCHDOG_ACTION__MAX; i++) {
        add_completion_option(rs, str, WatchdogAction_str(i));
    }
}

void migrate_set_capability_completion(ReadLineState *rs, int nb_args,
                                       const char *str)
{
    size_t len;

    len = strlen(str);
    readline_set_completion_index(rs, len);
    if (nb_args == 2) {
        int i;
        for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
            const char *name = MigrationCapability_str(i);
            if (!strncmp(str, name, len)) {
                readline_add_completion(rs, name);
            }
        }
    } else if (nb_args == 3) {
        add_completion_option(rs, str, "on");
        add_completion_option(rs, str, "off");
    }
}

void migrate_set_parameter_completion(ReadLineState *rs, int nb_args,
                                      const char *str)
{
    size_t len;

    len = strlen(str);
    readline_set_completion_index(rs, len);
    if (nb_args == 2) {
        int i;
        for (i = 0; i < MIGRATION_PARAMETER__MAX; i++) {
            const char *name = MigrationParameter_str(i);
            if (!strncmp(str, name, len)) {
                readline_add_completion(rs, name);
            }
        }
    }
}

static void vm_completion(ReadLineState *rs, const char *str)
{
    size_t len;
    BlockDriverState *bs;
    BdrvNextIterator it;

    len = strlen(str);
    readline_set_completion_index(rs, len);

    for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
        SnapshotInfoList *snapshots, *snapshot;
        AioContext *ctx = bdrv_get_aio_context(bs);
        bool ok = false;

        aio_context_acquire(ctx);
        if (bdrv_can_snapshot(bs)) {
            ok = bdrv_query_snapshot_info_list(bs, &snapshots, NULL) == 0;
        }
        aio_context_release(ctx);
        if (!ok) {
            continue;
        }

        snapshot = snapshots;
        while (snapshot) {
            char *completion = snapshot->value->name;
            if (!strncmp(str, completion, len)) {
                readline_add_completion(rs, completion);
            }
            completion = snapshot->value->id;
            if (!strncmp(str, completion, len)) {
                readline_add_completion(rs, completion);
            }
            snapshot = snapshot->next;
        }
        qapi_free_SnapshotInfoList(snapshots);
    }

}

void delvm_completion(ReadLineState *rs, int nb_args, const char *str)
{
    if (nb_args == 2) {
        vm_completion(rs, str);
    }
}

void loadvm_completion(ReadLineState *rs, int nb_args, const char *str)
{
    if (nb_args == 2) {
        vm_completion(rs, str);
    }
}

static void monitor_find_completion_by_table(Monitor *mon,
                                             const mon_cmd_t *cmd_table,
                                             char **args,
                                             int nb_args)
{
    const char *cmdname;
    int i;
    const char *ptype, *old_ptype, *str, *name;
    const mon_cmd_t *cmd;
    BlockBackend *blk = NULL;

    if (nb_args <= 1) {
        /* command completion */
        if (nb_args == 0)
            cmdname = "";
        else
            cmdname = args[0];
        readline_set_completion_index(mon->rs, strlen(cmdname));
        for (cmd = cmd_table; cmd->name != NULL; cmd++) {
            if (!runstate_check(RUN_STATE_PRECONFIG) ||
                 cmd_can_preconfig(cmd)) {
                cmd_completion(mon, cmdname, cmd->name);
            }
        }
    } else {
        /* find the command */
        for (cmd = cmd_table; cmd->name != NULL; cmd++) {
            if (compare_cmd(args[0], cmd->name) &&
                (!runstate_check(RUN_STATE_PRECONFIG) ||
                 cmd_can_preconfig(cmd))) {
                break;
            }
        }
        if (!cmd->name) {
            return;
        }

        if (cmd->sub_table) {
            /* do the job again */
            monitor_find_completion_by_table(mon, cmd->sub_table,
                                             &args[1], nb_args - 1);
            return;
        }
        if (cmd->command_completion) {
            cmd->command_completion(mon->rs, nb_args, args[nb_args - 1]);
            return;
        }

        ptype = next_arg_type(cmd->args_type);
        for(i = 0; i < nb_args - 2; i++) {
            if (*ptype != '\0') {
                ptype = next_arg_type(ptype);
                while (*ptype == '?')
                    ptype = next_arg_type(ptype);
            }
        }
        str = args[nb_args - 1];
        old_ptype = NULL;
        while (*ptype == '-' && old_ptype != ptype) {
            old_ptype = ptype;
            ptype = next_arg_type(ptype);
        }
        switch(*ptype) {
        case 'F':
            /* file completion */
            readline_set_completion_index(mon->rs, strlen(str));
            file_completion(mon, str);
            break;
        case 'B':
            /* block device name completion */
            readline_set_completion_index(mon->rs, strlen(str));
            while ((blk = blk_next(blk)) != NULL) {
                name = blk_name(blk);
                if (str[0] == '\0' ||
                    !strncmp(name, str, strlen(str))) {
                    readline_add_completion(mon->rs, name);
                }
            }
            break;
        case 's':
        case 'S':
            if (!strcmp(cmd->name, "help|?")) {
                monitor_find_completion_by_table(mon, cmd_table,
                                                 &args[1], nb_args - 1);
            }
            break;
        default:
            break;
        }
    }
}

static void monitor_find_completion(void *opaque,
                                    const char *cmdline)
{
    Monitor *mon = opaque;
    char *args[MAX_ARGS];
    int nb_args, len;

    /* 1. parse the cmdline */
    if (parse_cmdline(cmdline, &nb_args, args) < 0) {
        return;
    }

    /* if the line ends with a space, it means we want to complete the
       next arg */
    len = strlen(cmdline);
    if (len > 0 && qemu_isspace(cmdline[len - 1])) {
        if (nb_args >= MAX_ARGS) {
            goto cleanup;
        }
        args[nb_args++] = g_strdup("");
    }

    /* 2. auto complete according to args */
    monitor_find_completion_by_table(mon, mon->cmd_table, args, nb_args);

cleanup:
    free_cmdline_args(args, nb_args);
}

static int monitor_can_read(void *opaque)
{
    Monitor *mon = opaque;

    return !atomic_mb_read(&mon->suspend_cnt);
}

/*
 * Emit QMP response @rsp with ID @id to @mon.
 * Null @rsp can only happen for commands with QCO_NO_SUCCESS_RESP.
 * Nothing is emitted then.
 */
static void monitor_qmp_respond(MonitorQMP *mon, QDict *rsp)
{
    if (rsp) {
        qmp_send_response(mon, rsp);
    }
}

static void monitor_qmp_dispatch(MonitorQMP *mon, QObject *req)
{
    Monitor *old_mon;
    QDict *rsp;
    QDict *error;

    old_mon = cur_mon;
    cur_mon = &mon->common;

    rsp = qmp_dispatch(mon->commands, req, qmp_oob_enabled(mon));

    cur_mon = old_mon;

    if (mon->commands == &qmp_cap_negotiation_commands) {
        error = qdict_get_qdict(rsp, "error");
        if (error
            && !g_strcmp0(qdict_get_try_str(error, "class"),
                    QapiErrorClass_str(ERROR_CLASS_COMMAND_NOT_FOUND))) {
            /* Provide a more useful error message */
            qdict_del(error, "desc");
            qdict_put_str(error, "desc", "Expecting capabilities negotiation"
                          " with 'qmp_capabilities'");
        }
    }

    monitor_qmp_respond(mon, rsp);
    qobject_unref(rsp);
}

/*
 * Pop a QMP request from a monitor request queue.
 * Return the request, or NULL all request queues are empty.
 * We are using round-robin fashion to pop the request, to avoid
 * processing commands only on a very busy monitor.  To achieve that,
 * when we process one request on a specific monitor, we put that
 * monitor to the end of mon_list queue.
 *
 * Note: if the function returned with non-NULL, then the caller will
 * be with qmp_mon->qmp_queue_lock held, and the caller is responsible
 * to release it.
 */
static QMPRequest *monitor_qmp_requests_pop_any_with_lock(void)
{
    QMPRequest *req_obj = NULL;
    Monitor *mon;
    MonitorQMP *qmp_mon;

    qemu_mutex_lock(&monitor_lock);

    QTAILQ_FOREACH(mon, &mon_list, entry) {
        if (!monitor_is_qmp(mon)) {
            continue;
        }

        qmp_mon = container_of(mon, MonitorQMP, common);
        qemu_mutex_lock(&qmp_mon->qmp_queue_lock);
        req_obj = g_queue_pop_head(qmp_mon->qmp_requests);
        if (req_obj) {
            /* With the lock of corresponding queue held */
            break;
        }
        qemu_mutex_unlock(&qmp_mon->qmp_queue_lock);
    }

    if (req_obj) {
        /*
         * We found one request on the monitor. Degrade this monitor's
         * priority to lowest by re-inserting it to end of queue.
         */
        QTAILQ_REMOVE(&mon_list, mon, entry);
        QTAILQ_INSERT_TAIL(&mon_list, mon, entry);
    }

    qemu_mutex_unlock(&monitor_lock);

    return req_obj;
}

static void monitor_qmp_bh_dispatcher(void *data)
{
    QMPRequest *req_obj = monitor_qmp_requests_pop_any_with_lock();
    QDict *rsp;
    bool need_resume;
    MonitorQMP *mon;

    if (!req_obj) {
        return;
    }

    mon = req_obj->mon;
    /*  qmp_oob_enabled() might change after "qmp_capabilities" */
    need_resume = !qmp_oob_enabled(mon) ||
        mon->qmp_requests->length == QMP_REQ_QUEUE_LEN_MAX - 1;
    qemu_mutex_unlock(&mon->qmp_queue_lock);
    if (req_obj->req) {
        QDict *qdict = qobject_to(QDict, req_obj->req);
        QObject *id = qdict ? qdict_get(qdict, "id") : NULL;
        trace_monitor_qmp_cmd_in_band(qobject_get_try_str(id) ?: "");
        monitor_qmp_dispatch(mon, req_obj->req);
    } else {
        assert(req_obj->err);
        rsp = qmp_error_response(req_obj->err);
        req_obj->err = NULL;
        monitor_qmp_respond(mon, rsp);
        qobject_unref(rsp);
    }

    if (need_resume) {
        /* Pairs with the monitor_suspend() in handle_qmp_command() */
        monitor_resume(&mon->common);
    }
    qmp_request_free(req_obj);

    /* Reschedule instead of looping so the main loop stays responsive */
    qemu_bh_schedule(qmp_dispatcher_bh);
}

static void handle_qmp_command(void *opaque, QObject *req, Error *err)
{
    MonitorQMP *mon = opaque;
    QObject *id = NULL;
    QDict *qdict;
    QMPRequest *req_obj;

    assert(!req != !err);

    qdict = qobject_to(QDict, req);
    if (qdict) {
        id = qdict_get(qdict, "id");
    } /* else will fail qmp_dispatch() */

    if (req && trace_event_get_state_backends(TRACE_HANDLE_QMP_COMMAND)) {
        QString *req_json = qobject_to_json(req);
        trace_handle_qmp_command(mon, qstring_get_str(req_json));
        qobject_unref(req_json);
    }

    if (qdict && qmp_is_oob(qdict)) {
        /* OOB commands are executed immediately */
        trace_monitor_qmp_cmd_out_of_band(qobject_get_try_str(id) ?: "");
        monitor_qmp_dispatch(mon, req);
        qobject_unref(req);
        return;
    }

    req_obj = g_new0(QMPRequest, 1);
    req_obj->mon = mon;
    req_obj->req = req;
    req_obj->err = err;

    /* Protect qmp_requests and fetching its length. */
    qemu_mutex_lock(&mon->qmp_queue_lock);

    /*
     * Suspend the monitor when we can't queue more requests after
     * this one.  Dequeuing in monitor_qmp_bh_dispatcher() will resume
     * it.  Note that when OOB is disabled, we queue at most one
     * command, for backward compatibility.
     */
    if (!qmp_oob_enabled(mon) ||
        mon->qmp_requests->length == QMP_REQ_QUEUE_LEN_MAX - 1) {
        monitor_suspend(&mon->common);
    }

    /*
     * Put the request to the end of queue so that requests will be
     * handled in time order.  Ownership for req_obj, req,
     * etc. will be delivered to the handler side.
     */
    assert(mon->qmp_requests->length < QMP_REQ_QUEUE_LEN_MAX);
    g_queue_push_tail(mon->qmp_requests, req_obj);
    qemu_mutex_unlock(&mon->qmp_queue_lock);

    /* Kick the dispatcher routine */
    qemu_bh_schedule(qmp_dispatcher_bh);
}

static void monitor_qmp_read(void *opaque, const uint8_t *buf, int size)
{
    MonitorQMP *mon = opaque;

    json_message_parser_feed(&mon->parser, (const char *) buf, size);
}

static void monitor_read(void *opaque, const uint8_t *buf, int size)
{
    Monitor *old_mon = cur_mon;
    int i;

    cur_mon = opaque;

    if (cur_mon->rs) {
        for (i = 0; i < size; i++)
            readline_handle_byte(cur_mon->rs, buf[i]);
    } else {
        if (size == 0 || buf[size - 1] != 0)
            monitor_printf(cur_mon, "corrupted command\n");
        else
            handle_hmp_command(cur_mon, (char *)buf);
    }

    cur_mon = old_mon;
}

static void monitor_command_cb(void *opaque, const char *cmdline,
                               void *readline_opaque)
{
    Monitor *mon = opaque;

    monitor_suspend(mon);
    handle_hmp_command(mon, cmdline);
    monitor_resume(mon);
}

int monitor_suspend(Monitor *mon)
{
    if (monitor_is_hmp_non_interactive(mon)) {
        return -ENOTTY;
    }

    atomic_inc(&mon->suspend_cnt);

    if (mon->use_io_thread) {
        /*
         * Kick I/O thread to make sure this takes effect.  It'll be
         * evaluated again in prepare() of the watch object.
         */
        aio_notify(iothread_get_aio_context(mon_iothread));
    }

    trace_monitor_suspend(mon, 1);
    return 0;
}

static void monitor_accept_input(void *opaque)
{
    Monitor *mon = opaque;

    qemu_chr_fe_accept_input(&mon->chr);
}

void monitor_resume(Monitor *mon)
{
    if (monitor_is_hmp_non_interactive(mon)) {
        return;
    }

    if (atomic_dec_fetch(&mon->suspend_cnt) == 0) {
        AioContext *ctx;

        if (mon->use_io_thread) {
            ctx = iothread_get_aio_context(mon_iothread);
        } else {
            ctx = qemu_get_aio_context();
        }

        if (!monitor_is_qmp(mon)) {
            assert(mon->rs);
            readline_show_prompt(mon->rs);
        }

        aio_bh_schedule_oneshot(ctx, monitor_accept_input, mon);
    }

    trace_monitor_suspend(mon, -1);
}

static QDict *qmp_greeting(MonitorQMP *mon)
{
    QList *cap_list = qlist_new();
    QObject *ver = NULL;
    QMPCapability cap;

    qmp_marshal_query_version(NULL, &ver, NULL);

    for (cap = 0; cap < QMP_CAPABILITY__MAX; cap++) {
        if (mon->capab_offered[cap]) {
            qlist_append_str(cap_list, QMPCapability_str(cap));
        }
    }

    return qdict_from_jsonf_nofail(
        "{'QMP': {'version': %p, 'capabilities': %p}}",
        ver, cap_list);
}

static void monitor_qmp_event(void *opaque, int event)
{
    QDict *data;
    MonitorQMP *mon = opaque;

    switch (event) {
    case CHR_EVENT_OPENED:
        mon->commands = &qmp_cap_negotiation_commands;
        monitor_qmp_caps_reset(mon);
        data = qmp_greeting(mon);
        qmp_send_response(mon, data);
        qobject_unref(data);
        mon_refcount++;
        break;
    case CHR_EVENT_CLOSED:
        /*
         * Note: this is only useful when the output of the chardev
         * backend is still open.  For example, when the backend is
         * stdio, it's possible that stdout is still open when stdin
         * is closed.
         */
        monitor_qmp_cleanup_queues(mon);
        json_message_parser_destroy(&mon->parser);
        json_message_parser_init(&mon->parser, handle_qmp_command,
                                 mon, NULL);
        mon_refcount--;
        monitor_fdsets_cleanup();
        break;
    }
}

static void monitor_event(void *opaque, int event)
{
    Monitor *mon = opaque;

    switch (event) {
    case CHR_EVENT_MUX_IN:
        qemu_mutex_lock(&mon->mon_lock);
        mon->mux_out = 0;
        qemu_mutex_unlock(&mon->mon_lock);
        if (mon->reset_seen) {
            readline_restart(mon->rs);
            monitor_resume(mon);
            monitor_flush(mon);
        } else {
            atomic_mb_set(&mon->suspend_cnt, 0);
        }
        break;

    case CHR_EVENT_MUX_OUT:
        if (mon->reset_seen) {
            if (atomic_mb_read(&mon->suspend_cnt) == 0) {
                monitor_printf(mon, "\n");
            }
            monitor_flush(mon);
            monitor_suspend(mon);
        } else {
            atomic_inc(&mon->suspend_cnt);
        }
        qemu_mutex_lock(&mon->mon_lock);
        mon->mux_out = 1;
        qemu_mutex_unlock(&mon->mon_lock);
        break;

    case CHR_EVENT_OPENED:
        monitor_printf(mon, "QEMU %s monitor - type 'help' for more "
                       "information\n", QEMU_VERSION);
        if (!mon->mux_out) {
            readline_restart(mon->rs);
            readline_show_prompt(mon->rs);
        }
        mon->reset_seen = 1;
        mon_refcount++;
        break;

    case CHR_EVENT_CLOSED:
        mon_refcount--;
        monitor_fdsets_cleanup();
        break;
    }
}

static int
compare_mon_cmd(const void *a, const void *b)
{
    return strcmp(((const mon_cmd_t *)a)->name,
            ((const mon_cmd_t *)b)->name);
}

static void sortcmdlist(void)
{
    int array_num;
    int elem_size = sizeof(mon_cmd_t);

    array_num = sizeof(mon_cmds)/elem_size-1;
    qsort((void *)mon_cmds, array_num, elem_size, compare_mon_cmd);

    array_num = sizeof(info_cmds)/elem_size-1;
    qsort((void *)info_cmds, array_num, elem_size, compare_mon_cmd);
}

static void monitor_iothread_init(void)
{
    mon_iothread = iothread_create("mon_iothread", &error_abort);
}

void monitor_init_globals(void)
{
    monitor_init_qmp_commands();
    monitor_qapi_event_init();
    sortcmdlist();
    qemu_mutex_init(&monitor_lock);
    qemu_mutex_init(&mon_fdsets_lock);

    /*
     * The dispatcher BH must run in the main loop thread, since we
     * have commands assuming that context.  It would be nice to get
     * rid of those assumptions.
     */
    qmp_dispatcher_bh = aio_bh_new(iohandler_get_aio_context(),
                                   monitor_qmp_bh_dispatcher,
                                   NULL);
}

/* These functions just adapt the readline interface in a typesafe way.  We
 * could cast function pointers but that discards compiler checks.
 */
static void GCC_FMT_ATTR(2, 3) monitor_readline_printf(void *opaque,
                                                       const char *fmt, ...)
{
    va_list ap;
    va_start(ap, fmt);
    monitor_vprintf(opaque, fmt, ap);
    va_end(ap);
}

static void monitor_readline_flush(void *opaque)
{
    monitor_flush(opaque);
}

/*
 * Print to current monitor if we have one, else to stderr.
 */
int error_vprintf(const char *fmt, va_list ap)
{
    if (cur_mon && !monitor_cur_is_qmp()) {
        return monitor_vprintf(cur_mon, fmt, ap);
    }
    return vfprintf(stderr, fmt, ap);
}

int error_vprintf_unless_qmp(const char *fmt, va_list ap)
{
    if (!cur_mon) {
        return vfprintf(stderr, fmt, ap);
    }
    if (!monitor_cur_is_qmp()) {
        return monitor_vprintf(cur_mon, fmt, ap);
    }
    return -1;
}

static void monitor_list_append(Monitor *mon)
{
    qemu_mutex_lock(&monitor_lock);
    /*
     * This prevents inserting new monitors during monitor_cleanup().
     * A cleaner solution would involve the main thread telling other
     * threads to terminate, waiting for their termination.
     */
    if (!monitor_destroyed) {
        QTAILQ_INSERT_HEAD(&mon_list, mon, entry);
        mon = NULL;
    }
    qemu_mutex_unlock(&monitor_lock);

    if (mon) {
        monitor_data_destroy(mon);
        g_free(mon);
    }
}

static void monitor_qmp_setup_handlers_bh(void *opaque)
{
    MonitorQMP *mon = opaque;
    GMainContext *context;

    assert(mon->common.use_io_thread);
    context = iothread_get_g_main_context(mon_iothread);
    assert(context);
    qemu_chr_fe_set_handlers(&mon->common.chr, monitor_can_read,
                             monitor_qmp_read, monitor_qmp_event,
                             NULL, &mon->common, context, true);
    monitor_list_append(&mon->common);
}

static void monitor_init_qmp(Chardev *chr, int flags)
{
    MonitorQMP *mon = g_new0(MonitorQMP, 1);

    /* Only HMP supports readline */
    assert(!(flags & MONITOR_USE_READLINE));

    /* Note: we run QMP monitor in I/O thread when @chr supports that */
    monitor_data_init(&mon->common, flags, false,
                      qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_GCONTEXT));

    qemu_mutex_init(&mon->qmp_queue_lock);
    mon->qmp_requests = g_queue_new();

    qemu_chr_fe_init(&mon->common.chr, chr, &error_abort);
    qemu_chr_fe_set_echo(&mon->common.chr, true);

    json_message_parser_init(&mon->parser, handle_qmp_command, mon, NULL);
    if (mon->common.use_io_thread) {
        /*
         * Make sure the old iowatch is gone.  It's possible when
         * e.g. the chardev is in client mode, with wait=on.
         */
        remove_fd_in_watch(chr);
        /*
         * We can't call qemu_chr_fe_set_handlers() directly here
         * since chardev might be running in the monitor I/O
         * thread.  Schedule a bottom half.
         */
        aio_bh_schedule_oneshot(iothread_get_aio_context(mon_iothread),
                                monitor_qmp_setup_handlers_bh, mon);
        /* The bottom half will add @mon to @mon_list */
    } else {
        qemu_chr_fe_set_handlers(&mon->common.chr, monitor_can_read,
                                 monitor_qmp_read, monitor_qmp_event,
                                 NULL, &mon->common, NULL, true);
        monitor_list_append(&mon->common);
    }
}

static void monitor_init_hmp(Chardev *chr, int flags)
{
    Monitor *mon = g_new0(Monitor, 1);
    bool use_readline = flags & MONITOR_USE_READLINE;

    monitor_data_init(mon, flags, false, false);
    qemu_chr_fe_init(&mon->chr, chr, &error_abort);

    if (use_readline) {
        mon->rs = readline_init(monitor_readline_printf,
                                monitor_readline_flush,
                                mon,
                                monitor_find_completion);
        monitor_read_command(mon, 0);
    }

    qemu_chr_fe_set_handlers(&mon->chr, monitor_can_read, monitor_read,
                             monitor_event, NULL, mon, NULL, true);
    monitor_list_append(mon);
}

void monitor_init(Chardev *chr, int flags)
{
    if (flags & MONITOR_USE_CONTROL) {
        monitor_init_qmp(chr, flags);
    } else {
        monitor_init_hmp(chr, flags);
    }
}

void monitor_cleanup(void)
{
    /*
     * We need to explicitly stop the I/O thread (but not destroy it),
     * clean up the monitor resources, then destroy the I/O thread since
     * we need to unregister from chardev below in
     * monitor_data_destroy(), and chardev is not thread-safe yet
     */
    if (mon_iothread) {
        iothread_stop(mon_iothread);
    }

    /* Flush output buffers and destroy monitors */
    qemu_mutex_lock(&monitor_lock);
    monitor_destroyed = true;
    while (!QTAILQ_EMPTY(&mon_list)) {
        Monitor *mon = QTAILQ_FIRST(&mon_list);
        QTAILQ_REMOVE(&mon_list, mon, entry);
        /* Permit QAPI event emission from character frontend release */
        qemu_mutex_unlock(&monitor_lock);
        monitor_flush(mon);
        monitor_data_destroy(mon);
        qemu_mutex_lock(&monitor_lock);
        g_free(mon);
    }
    qemu_mutex_unlock(&monitor_lock);

    /* QEMUBHs needs to be deleted before destroying the I/O thread */
    qemu_bh_delete(qmp_dispatcher_bh);
    qmp_dispatcher_bh = NULL;
    if (mon_iothread) {
        iothread_destroy(mon_iothread);
        mon_iothread = NULL;
    }
}

QemuOptsList qemu_mon_opts = {
    .name = "mon",
    .implied_opt_name = "chardev",
    .head = QTAILQ_HEAD_INITIALIZER(qemu_mon_opts.head),
    .desc = {
        {
            .name = "mode",
            .type = QEMU_OPT_STRING,
        },{
            .name = "chardev",
            .type = QEMU_OPT_STRING,
        },{
            .name = "pretty",
            .type = QEMU_OPT_BOOL,
        },
        { /* end of list */ }
    },
};

HotpluggableCPUList *qmp_query_hotpluggable_cpus(Error **errp)
{
    MachineState *ms = MACHINE(qdev_get_machine());
    MachineClass *mc = MACHINE_GET_CLASS(ms);

    if (!mc->has_hotpluggable_cpus) {
        error_setg(errp, QERR_FEATURE_DISABLED, "query-hotpluggable-cpus");
        return NULL;
    }

    return machine_query_hotpluggable_cpus(ms);
}