diff options
author | Peter Maydell <peter.maydell@linaro.org> | 2018-06-19 15:19:07 +0100 |
---|---|---|
committer | Peter Maydell <peter.maydell@linaro.org> | 2018-06-19 15:19:07 +0100 |
commit | a01fba4687b9a2464ed9b0eee60bb42b8f81f61b (patch) | |
tree | 35f36b0261a77da65157dc7de424c35785a0397c | |
parent | e8729c154b3fb97232e640a43c832122f0fdd32d (diff) | |
parent | 474514668b47c9d2148b526e379ffbb6764d9a9e (diff) |
Merge remote-tracking branch 'remotes/armbru/tags/pull-monitor-2018-06-18' into staging
Monitor patches for 2018-06-18
# gpg: Signature made Mon 18 Jun 2018 14:50:29 BST
# gpg: using RSA key 3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653
* remotes/armbru/tags/pull-monitor-2018-06-18:
monitor: add lock to protect mon_fdsets
monitor: move init global earlier
monitor: remove event_clock_type
monitor: fix comment for monitor_lock
monitor: more comments on lock-free elements
monitor: protect mon->fds with mon_lock
monitor: rename out_lock to mon_lock
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r-- | monitor.c | 168 | ||||
-rw-r--r-- | stubs/fdset.c | 2 | ||||
-rw-r--r-- | util/osdep.c | 3 | ||||
-rw-r--r-- | vl.c | 7 |
4 files changed, 121 insertions, 59 deletions
@@ -207,22 +207,35 @@ struct Monitor { bool skip_flush; bool use_io_thr; - /* We can't access guest memory when holding the lock */ - QemuMutex out_lock; - QString *outbuf; - guint out_watch; - - /* Read under either BQL or out_lock, written with BQL+out_lock. */ - int mux_out; - + /* + * State used only in the thread "owning" the monitor. + * If @use_io_thr, this is mon_global.mon_iothread. + * Else, it's the main thread. + * These members can be safely accessed without locks. + */ ReadLineState *rs; + MonitorQMP qmp; gchar *mon_cpu_path; BlockCompletionFunc *password_completion_cb; void *password_opaque; mon_cmd_t *cmd_table; - QLIST_HEAD(,mon_fd_t) fds; QTAILQ_ENTRY(Monitor) entry; + + /* + * The per-monitor lock. We can't access guest memory when holding + * the lock. + */ + QemuMutex mon_lock; + + /* + * Fields 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; }; /* Let's add monitor global variables to this struct. */ @@ -253,11 +266,15 @@ typedef struct QMPRequest QMPRequest; /* QMP checker flags */ #define QMP_ACCEPT_UNKNOWNS 1 -/* Protects mon_list, monitor_event_state. */ +/* Protects mon_list, monitor_qapi_event_state. */ static QemuMutex monitor_lock; - +static GHashTable *monitor_qapi_event_state; static QTAILQ_HEAD(mon_list, Monitor) mon_list; + +/* Protects mon_fdsets */ +static QemuMutex mon_fdsets_lock; static QLIST_HEAD(mon_fdsets, MonFdset) mon_fdsets; + static int mon_refcount; static mon_cmd_t mon_cmds[]; @@ -267,8 +284,6 @@ QmpCommandList qmp_commands, qmp_cap_negotiation_commands; Monitor *cur_mon; -static QEMUClockType event_clock_type = QEMU_CLOCK_REALTIME; - static void monitor_command_cb(void *opaque, const char *cmdline, void *readline_opaque); @@ -295,6 +310,19 @@ 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. + * Beware: result is invalid before configure_accelerator(). + */ +static inline QEMUClockType monitor_get_event_clock(void) +{ + /* + * This allows us to perform tests on the monitor queues to verify + * that the rate limits are enforced. + */ + return qtest_enabled() ? QEMU_CLOCK_VIRTUAL : QEMU_CLOCK_REALTIME; +} + /** * Is the current monitor, if any, a QMP monitor? */ @@ -365,14 +393,14 @@ static gboolean monitor_unblocked(GIOChannel *chan, GIOCondition cond, { Monitor *mon = opaque; - qemu_mutex_lock(&mon->out_lock); + qemu_mutex_lock(&mon->mon_lock); mon->out_watch = 0; monitor_flush_locked(mon); - qemu_mutex_unlock(&mon->out_lock); + qemu_mutex_unlock(&mon->mon_lock); return FALSE; } -/* Called with mon->out_lock held. */ +/* Called with mon->mon_lock held. */ static void monitor_flush_locked(Monitor *mon) { int rc; @@ -410,9 +438,9 @@ static void monitor_flush_locked(Monitor *mon) void monitor_flush(Monitor *mon) { - qemu_mutex_lock(&mon->out_lock); + qemu_mutex_lock(&mon->mon_lock); monitor_flush_locked(mon); - qemu_mutex_unlock(&mon->out_lock); + qemu_mutex_unlock(&mon->mon_lock); } /* flush at every end of line */ @@ -420,7 +448,7 @@ static void monitor_puts(Monitor *mon, const char *str) { char c; - qemu_mutex_lock(&mon->out_lock); + qemu_mutex_lock(&mon->mon_lock); for(;;) { c = *str++; if (c == '\0') @@ -433,7 +461,7 @@ static void monitor_puts(Monitor *mon, const char *str) monitor_flush_locked(mon); } } - qemu_mutex_unlock(&mon->out_lock); + qemu_mutex_unlock(&mon->mon_lock); } void monitor_vprintf(Monitor *mon, const char *fmt, va_list ap) @@ -558,8 +586,6 @@ static MonitorQAPIEventConf monitor_qapi_event_conf[QAPI_EVENT__MAX] = { [QAPI_EVENT_VSERPORT_CHANGE] = { 1000 * SCALE_MS }, }; -GHashTable *monitor_qapi_event_state; - /* * Emits the event to every monitor instance, @event is only used for trace * Called with monitor_lock held. @@ -620,7 +646,7 @@ monitor_qapi_event_queue(QAPIEvent event, QDict *qdict, Error **errp) * 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(event_clock_type); + int64_t now = qemu_clock_get_ns(monitor_get_event_clock()); monitor_qapi_event_emit(event, qdict); @@ -628,7 +654,7 @@ monitor_qapi_event_queue(QAPIEvent event, QDict *qdict, Error **errp) evstate->event = event; evstate->data = qobject_ref(data); evstate->qdict = NULL; - evstate->timer = timer_new_ns(event_clock_type, + evstate->timer = timer_new_ns(monitor_get_event_clock(), monitor_qapi_event_handler, evstate); g_hash_table_add(monitor_qapi_event_state, evstate); @@ -653,7 +679,7 @@ static void monitor_qapi_event_handler(void *opaque) qemu_mutex_lock(&monitor_lock); if (evstate->qdict) { - int64_t now = qemu_clock_get_ns(event_clock_type); + int64_t now = qemu_clock_get_ns(monitor_get_event_clock()); monitor_qapi_event_emit(evstate->event, evstate->qdict); qobject_unref(evstate->qdict); @@ -709,10 +735,6 @@ static gboolean qapi_event_throttle_equal(const void *a, const void *b) static void monitor_qapi_event_init(void) { - if (qtest_enabled()) { - event_clock_type = QEMU_CLOCK_VIRTUAL; - } - monitor_qapi_event_state = g_hash_table_new(qapi_event_throttle_hash, qapi_event_throttle_equal); qmp_event_set_func_emit(monitor_qapi_event_queue); @@ -724,7 +746,7 @@ static void monitor_data_init(Monitor *mon, bool skip_flush, bool use_io_thr) { memset(mon, 0, sizeof(Monitor)); - qemu_mutex_init(&mon->out_lock); + qemu_mutex_init(&mon->mon_lock); qemu_mutex_init(&mon->qmp.qmp_queue_lock); mon->outbuf = qstring_new(); /* Use *mon_cmds by default. */ @@ -744,7 +766,7 @@ static void monitor_data_destroy(Monitor *mon) } readline_free(mon->rs); qobject_unref(mon->outbuf); - qemu_mutex_destroy(&mon->out_lock); + qemu_mutex_destroy(&mon->mon_lock); qemu_mutex_destroy(&mon->qmp.qmp_queue_lock); monitor_qmp_cleanup_req_queue_locked(mon); monitor_qmp_cleanup_resp_queue_locked(mon); @@ -776,13 +798,13 @@ char *qmp_human_monitor_command(const char *command_line, bool has_cpu_index, handle_hmp_command(&hmp, command_line); cur_mon = old_mon; - qemu_mutex_lock(&hmp.out_lock); + 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.out_lock); + qemu_mutex_unlock(&hmp.mon_lock); out: monitor_data_destroy(&hmp); @@ -1306,7 +1328,7 @@ void qmp_qmp_capabilities(bool has_enable, QMPCapabilityList *enable, cur_mon->qmp.commands = &qmp_commands; } -/* set the current CPU defined by the user */ +/* Set the current CPU defined by the user. Callers must hold BQL. */ int monitor_set_cpu(int cpu_index) { CPUState *cpu; @@ -1320,6 +1342,7 @@ int monitor_set_cpu(int cpu_index) return 0; } +/* Callers must hold BQL. */ static CPUState *mon_get_cpu_sync(bool synchronize) { CPUState *cpu; @@ -2182,7 +2205,7 @@ static void hmp_acl_remove(Monitor *mon, const QDict *qdict) void qmp_getfd(const char *fdname, Error **errp) { mon_fd_t *monfd; - int fd; + int fd, tmp_fd; fd = qemu_chr_fe_get_msgfd(&cur_mon->chr); if (fd == -1) { @@ -2197,13 +2220,17 @@ void qmp_getfd(const char *fdname, Error **errp) return; } + qemu_mutex_lock(&cur_mon->mon_lock); QLIST_FOREACH(monfd, &cur_mon->fds, next) { if (strcmp(monfd->name, fdname) != 0) { continue; } - close(monfd->fd); + tmp_fd = monfd->fd; monfd->fd = fd; + qemu_mutex_unlock(&cur_mon->mon_lock); + /* Make sure close() is out of critical section */ + close(tmp_fd); return; } @@ -2212,24 +2239,31 @@ void qmp_getfd(const char *fdname, Error **errp) 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); - close(monfd->fd); + tmp_fd = monfd->fd; g_free(monfd->name); g_free(monfd); + qemu_mutex_unlock(&cur_mon->mon_lock); + /* Make sure close() is out of critical section */ + close(tmp_fd); return; } + qemu_mutex_unlock(&cur_mon->mon_lock); error_setg(errp, QERR_FD_NOT_FOUND, fdname); } @@ -2237,6 +2271,7 @@ 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; @@ -2250,10 +2285,12 @@ int monitor_get_fd(Monitor *mon, const char *fdname, Error **errp) 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; } @@ -2285,9 +2322,11 @@ 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, @@ -2322,6 +2361,7 @@ void qmp_remove_fd(int64_t fdset_id, bool has_fd, int64_t fd, Error **errp) 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; @@ -2341,10 +2381,12 @@ void qmp_remove_fd(int64_t fdset_id, bool has_fd, int64_t fd, Error **errp) 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); @@ -2360,6 +2402,7 @@ FdsetInfoList *qmp_query_fdsets(Error **errp) 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; @@ -2389,6 +2432,7 @@ FdsetInfoList *qmp_query_fdsets(Error **errp) fdset_info->next = fdset_list; fdset_list = fdset_info; } + qemu_mutex_unlock(&mon_fdsets_lock); return fdset_list; } @@ -2401,6 +2445,7 @@ AddfdInfo *monitor_fdset_add_fd(int fd, bool has_fdset_id, int64_t fdset_id, 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 */ @@ -2421,6 +2466,7 @@ AddfdInfo *monitor_fdset_add_fd(int fd, bool has_fdset_id, int64_t 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 */ @@ -2471,16 +2517,21 @@ AddfdInfo *monitor_fdset_add_fd(int fd, bool has_fdset_id, int64_t fdset_id, 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) { -#ifndef _WIN32 +#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; @@ -2488,20 +2539,24 @@ int monitor_fdset_get_fd(int64_t fdset_id, int flags) QLIST_FOREACH(mon_fdset_fd, &mon_fdset->fds, next) { mon_fd_flags = fcntl(mon_fdset_fd->fd, F_GETFL); if (mon_fd_flags == -1) { - return -1; + ret = -errno; + goto out; } if ((flags & O_ACCMODE) == (mon_fd_flags & O_ACCMODE)) { - return mon_fdset_fd->fd; + ret = mon_fdset_fd->fd; + goto out; } } - errno = EACCES; - return -1; + ret = -EACCES; + goto out; } -#endif + ret = -ENOENT; - errno = ENOENT; - return -1; +out: + qemu_mutex_unlock(&mon_fdsets_lock); + return ret; +#endif } int monitor_fdset_dup_fd_add(int64_t fdset_id, int dup_fd) @@ -2509,20 +2564,25 @@ 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) { - return -1; + 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; } @@ -2531,6 +2591,7 @@ static int 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) { @@ -2539,13 +2600,17 @@ static int monitor_fdset_dup_fd_find_remove(int dup_fd, bool remove) if (QLIST_EMPTY(&mon_fdset->dup_fds)) { monitor_fdset_cleanup(mon_fdset); } - return -1; + goto err; } else { + qemu_mutex_unlock(&mon_fdsets_lock); return mon_fdset->id; } } } } + +err: + qemu_mutex_unlock(&mon_fdsets_lock); return -1; } @@ -4381,9 +4446,9 @@ static void monitor_event(void *opaque, int event) switch (event) { case CHR_EVENT_MUX_IN: - qemu_mutex_lock(&mon->out_lock); + qemu_mutex_lock(&mon->mon_lock); mon->mux_out = 0; - qemu_mutex_unlock(&mon->out_lock); + qemu_mutex_unlock(&mon->mon_lock); if (mon->reset_seen) { readline_restart(mon->rs); monitor_resume(mon); @@ -4403,9 +4468,9 @@ static void monitor_event(void *opaque, int event) } else { atomic_inc(&mon->suspend_cnt); } - qemu_mutex_lock(&mon->out_lock); + qemu_mutex_lock(&mon->mon_lock); mon->mux_out = 1; - qemu_mutex_unlock(&mon->out_lock); + qemu_mutex_unlock(&mon->mon_lock); break; case CHR_EVENT_OPENED: @@ -4485,6 +4550,7 @@ void monitor_init_globals(void) monitor_qapi_event_init(); sortcmdlist(); qemu_mutex_init(&monitor_lock); + qemu_mutex_init(&mon_fdsets_lock); monitor_iothread_init(); } diff --git a/stubs/fdset.c b/stubs/fdset.c index 6020cf28c8..4f3edf2ea4 100644 --- a/stubs/fdset.c +++ b/stubs/fdset.c @@ -14,7 +14,7 @@ int monitor_fdset_dup_fd_find(int dup_fd) int monitor_fdset_get_fd(int64_t fdset_id, int flags) { - return -1; + return -ENOENT; } void monitor_fdset_dup_fd_remove(int dupfd) diff --git a/util/osdep.c b/util/osdep.c index a73de0e1ba..ea51d500b6 100644 --- a/util/osdep.c +++ b/util/osdep.c @@ -302,7 +302,8 @@ int qemu_open(const char *name, int flags, ...) } fd = monitor_fdset_get_fd(fdset_id, flags); - if (fd == -1) { + if (fd < 0) { + errno = -fd; return -1; } @@ -2978,6 +2978,7 @@ int main(int argc, char **argv, char **envp) runstate_init(); postcopy_infrastructure_init(); + monitor_init_globals(); if (qcrypto_init(&err) < 0) { error_reportf_err(err, "cannot initialize crypto: "); @@ -4412,12 +4413,6 @@ int main(int argc, char **argv, char **envp) default_drive(default_floppy, snapshot, IF_FLOPPY, 0, FD_OPTS); default_drive(default_sdcard, snapshot, IF_SD, 0, SD_OPTS); - /* - * Note: qtest_enabled() (which is used in monitor_qapi_event_init()) - * depends on configure_accelerator() above. - */ - monitor_init_globals(); - if (qemu_opts_foreach(qemu_find_opts("mon"), mon_init_func, NULL, NULL)) { exit(1); |