monitor: Split out monitor/monitor.c

Move the monitor core infrastructure from monitor/misc.c to
monitor/monitor.c. This is code that can be shared for all targets, so
compile it only once.

What remains in monitor/misc.c after this patch is mostly monitor
command implementations (which could move to hmp-cmds.c or qmp-cmds.c
later) and code that requires a system emulator or is even
target-dependent (including HMP command completion code).

The amount of function and particularly extern variables in
monitor_int.h is probably a bit larger than it needs to be, but this way
no non-trivial code modifications are needed. The interfaces between all
monitor parts can be cleaned up later.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20190613153405.24769-13-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Superfluous #include dropped]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

1 files changed, 1 insertions, 597 deletions

diff --git a/monitor/misc.c b/monitor/misc.c
index e4d656f002..6e3d580ae7 100644
--- a/monitor/misc.c
+++ b/monitor/misc.c
@@ -54,7 +54,6 @@
 #include "qapi/qmp/qerror.h"
 #include "qapi/qmp/qstring.h"
 #include "qom/object_interfaces.h"
-#include "trace.h"
 #include "trace/control.h"
 #include "monitor/hmp-target.h"
 #ifdef CONFIG_TRACE_SIMPLE
@@ -71,7 +70,6 @@
 #include "qapi/error.h"
 #include "qapi/qmp-event.h"
 #include "qapi/qapi-introspect.h"
-#include "sysemu/qtest.h"
 #include "sysemu/cpus.h"
 #include "qemu/cutils.h"
 #include "tcg/tcg.h"
@@ -107,427 +105,15 @@ struct MonFdset {
     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;
-
-/* Shared monitor I/O thread */
-IOThread *mon_iothread;
-
-/* Bottom half to dispatch the requests received from I/O thread */
-QEMUBH *qmp_dispatcher_bh;
-
 /* QMP checker flags */
 #define QMP_ACCEPT_UNKNOWNS 1
 
-/* Protects mon_list, monitor_qapi_event_state, monitor_destroyed.  */
-QemuMutex monitor_lock;
-static GHashTable *monitor_qapi_event_state;
-MonitorList mon_list;
-static bool monitor_destroyed;
-
 /* Protects mon_fdsets */
 static QemuMutex mon_fdsets_lock;
 static QLIST_HEAD(, MonFdset) mon_fdsets;
 
-int mon_refcount;
-
 static HMPCommand hmp_info_cmds[];
 
-__thread Monitor *cur_mon;
-
-/**
- * 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);
-}
-
-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 */
-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 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 monitor_iothread_init(void);
-
-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();
-    mon->skip_flush = skip_flush;
-    mon->use_io_thread = use_io_thread;
-    mon->flags = flags;
-}
-
-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));
-    } else {
-        readline_free(container_of(mon, MonitorHMP, common)->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)
 {
@@ -2728,67 +2314,6 @@ void loadvm_completion(ReadLineState *rs, int nb_args, const char *str)
     }
 }
 
-int monitor_can_read(void *opaque)
-{
-    Monitor *mon = opaque;
-
-    return !atomic_mb_read(&mon->suspend_cnt);
-}
-
-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)) {
-            MonitorHMP *hmp_mon = container_of(mon, MonitorHMP, common);
-            assert(hmp_mon->rs);
-            readline_show_prompt(hmp_mon->rs);
-        }
-
-        aio_bh_schedule_oneshot(ctx, monitor_accept_input, mon);
-    }
-
-    trace_monitor_suspend(mon, -1);
-}
-
 static int
 compare_mon_cmd(const void *a, const void *b)
 {
@@ -2806,135 +2331,14 @@ static void sortcmdlist(void)
           compare_mon_cmd);
 }
 
-static void monitor_iothread_init(void)
-{
-    mon_iothread = iothread_create("mon_iothread", &error_abort);
-}
-
 void monitor_init_globals(void)
 {
+    monitor_init_globals_core();
     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);
-}
-
-/*
- * 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;
-}
-
-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);
-    }
-}
-
-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());