[{"id":3676949,"web_url":"http://patchwork.ozlabs.org/comment/3676949/","msgid":"","list_archive_url":null,"date":"2026-04-13T22:47:38","subject":"Re: [PATCH 16/17] monitor: eliminate monitor_is_hmp_non_interactive\n method","submitter":{"id":86099,"url":"http://patchwork.ozlabs.org/api/people/86099/","name":"Dr. David Alan Gilbert","email":"dave@treblig.org"},"content":"* Daniel P. Berrangé (berrange@redhat.com) wrote:\n> The monitor_is_hmp_non_interactive method is used by\n> monitor_suspend and monitor_resume, to make them a no-op\n> if the HMP does not use readline.\n> \n> There are only a handful of callers of suspend/resume and\n> they can be made to skip the call with readline is not\n> present.\n> \n> Signed-off-by: Daniel P. Berrangé \n\nReviewed-by: Dr. David Alan Gilbert \n\n> ---\n> include/monitor/monitor.h | 2 +-\n> migration/migration-hmp-cmds.c | 5 ++++-\n> monitor/hmp-cmds.c | 5 ++++-\n> monitor/hmp.c | 14 +++++++++-----\n> monitor/monitor-internal.h | 1 -\n> monitor/monitor.c | 30 +-----------------------------\n> 6 files changed, 19 insertions(+), 38 deletions(-)\n> \n> diff --git a/include/monitor/monitor.h b/include/monitor/monitor.h\n> index f66e465775..52df053c6d 100644\n> --- a/include/monitor/monitor.h\n> +++ b/include/monitor/monitor.h\n> @@ -34,7 +34,7 @@ int monitor_new(MonitorOptions *opts, bool allow_hmp, Error **errp);\n> int monitor_new_opts(QemuOpts *opts, Error **errp);\n> void monitor_cleanup(void);\n> \n> -int monitor_suspend(Monitor *mon);\n> +void monitor_suspend(Monitor *mon);\n> void monitor_resume(Monitor *mon);\n> \n> int monitor_get_fd(Monitor *mon, const char *fdname, Error **errp);\n> diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c\n> index 0a193b8f54..e9bb970b20 100644\n> --- a/migration/migration-hmp-cmds.c\n> +++ b/migration/migration-hmp-cmds.c\n> @@ -18,6 +18,7 @@\n> #include \"migration/snapshot.h\"\n> #include \"monitor/hmp.h\"\n> #include \"monitor/monitor.h\"\n> +#include \"monitor/monitor-internal.h\"\n> #include \"qapi/error.h\"\n> #include \"qapi/qapi-commands-migration.h\"\n> #include \"qapi/qapi-visit-migration.h\"\n> @@ -836,12 +837,14 @@ void hmp_migrate(Monitor *mon, const QDict *qdict)\n> \n> if (!detach) {\n> HMPMigrationStatus *status;\n> + MonitorHMP *hmp = MONITOR_HMP(mon);\n> \n> - if (monitor_suspend(mon) < 0) {\n> + if (!hmp->rs) {\n> monitor_printf(mon, \"terminal does not allow synchronous \"\n> \"migration, continuing detached\\n\");\n> return;\n> }\n> + monitor_suspend(mon);\n> \n> status = g_malloc0(sizeof(*status));\n> status->mon = mon;\n> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c\n> index 911d984cbe..a6314c1159 100644\n> --- a/monitor/hmp-cmds.c\n> +++ b/monitor/hmp-cmds.c\n> @@ -90,7 +90,10 @@ void hmp_info_version(Monitor *mon, const QDict *qdict)\n> \n> void hmp_quit(Monitor *mon, const QDict *qdict)\n> {\n> - monitor_suspend(mon);\n> + MonitorHMP *hmp = MONITOR_HMP(mon);\n> + if (hmp->rs) {\n> + monitor_suspend(mon);\n> + }\n> qmp_quit(NULL);\n> }\n> \n> diff --git a/monitor/hmp.c b/monitor/hmp.c\n> index 5f9373a87b..387dab2567 100644\n> --- a/monitor/hmp.c\n> +++ b/monitor/hmp.c\n> @@ -1491,13 +1491,16 @@ static void monitor_read(void *opaque, const uint8_t *buf, int size)\n> static void monitor_event(void *opaque, QEMUChrEvent event)\n> {\n> Monitor *mon = opaque;\n> + MonitorHMP *hmp = MONITOR_HMP(mon);\n> \n> switch (event) {\n> case CHR_EVENT_MUX_IN:\n> qemu_mutex_lock(&mon->mon_lock);\n> if (mon->mux_out) {\n> mon->mux_out = 0;\n> - monitor_resume(mon);\n> + if (hmp->rs) {\n> + monitor_resume(mon);\n> + }\n> }\n> qemu_mutex_unlock(&mon->mon_lock);\n> break;\n> @@ -1510,7 +1513,9 @@ static void monitor_event(void *opaque, QEMUChrEvent event)\n> } else {\n> monitor_flush_locked(mon);\n> }\n> - monitor_suspend(mon);\n> + if (hmp->rs) {\n> + monitor_suspend(mon);\n> + }\n> mon->mux_out = 1;\n> }\n> qemu_mutex_unlock(&mon->mon_lock);\n> @@ -1521,7 +1526,7 @@ static void monitor_event(void *opaque, QEMUChrEvent event)\n> \"information\\n\", QEMU_VERSION);\n> qemu_mutex_lock(&mon->mon_lock);\n> mon->reset_seen = 1;\n> - if (!mon->mux_out) {\n> + if (!mon->mux_out && hmp->rs) {\n> /* Suspend-resume forces the prompt to be printed. */\n> monitor_suspend(mon);\n> monitor_resume(mon);\n> @@ -1569,8 +1574,7 @@ void monitor_new_hmp(Chardev *chr, bool use_readline, Error **errp)\n> return;\n> }\n> \n> - mon->use_readline = use_readline;\n> - if (mon->use_readline) {\n> + if (use_readline) {\n> mon->rs = readline_init(monitor_readline_printf,\n> monitor_readline_flush,\n> mon,\n> diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h\n> index d40fdde793..7557deb978 100644\n> --- a/monitor/monitor-internal.h\n> +++ b/monitor/monitor-internal.h\n> @@ -133,7 +133,6 @@ struct MonitorHMPClass {\n> \n> struct MonitorHMP {\n> Monitor parent;\n> - bool use_readline;\n> /*\n> * State used only in the thread \"owning\" the monitor.\n> * If @use_io_thread, this is @mon_iothread. (This does not actually happen\n> diff --git a/monitor/monitor.c b/monitor/monitor.c\n> index f48603a7e8..3860486a32 100644\n> --- a/monitor/monitor.c\n> +++ b/monitor/monitor.c\n> @@ -130,25 +130,6 @@ Monitor *monitor_set_cur(Coroutine *co, Monitor *mon)\n> return old_monitor;\n> }\n> \n> -/**\n> - * Is @mon is using readline?\n> - * Note: not all HMP monitors use readline, e.g., gdbserver has a\n> - * non-interactive HMP monitor, so readline is not used there.\n> - */\n> -static inline bool monitor_uses_readline(const MonitorHMP *mon)\n> -{\n> - return mon->use_readline;\n> -}\n> -\n> -static inline bool monitor_is_hmp_non_interactive(const Monitor *mon)\n> -{\n> - if (!object_dynamic_cast(OBJECT(mon), TYPE_MONITOR_HMP)) {\n> - return false;\n> - }\n> -\n> - return !monitor_uses_readline(container_of(mon, MonitorHMP, parent));\n> -}\n> -\n> static gboolean monitor_unblocked(void *do_not_use, GIOCondition cond,\n> void *opaque)\n> {\n> @@ -523,12 +504,8 @@ static gboolean qapi_event_throttle_equal(const void *a, const void *b)\n> return TRUE;\n> }\n> \n> -int monitor_suspend(Monitor *mon)\n> +void monitor_suspend(Monitor *mon)\n> {\n> - if (monitor_is_hmp_non_interactive(mon)) {\n> - return -ENOTTY;\n> - }\n> -\n> qatomic_inc(&mon->suspend_cnt);\n> \n> if (mon->use_io_thread) {\n> @@ -540,7 +517,6 @@ int monitor_suspend(Monitor *mon)\n> }\n> \n> trace_monitor_suspend(mon, 1);\n> - return 0;\n> }\n> \n> static void monitor_accept_input(void *opaque)\n> @@ -557,10 +533,6 @@ static void monitor_accept_input(void *opaque)\n> \n> void monitor_resume(Monitor *mon)\n> {\n> - if (monitor_is_hmp_non_interactive(mon)) {\n> - return;\n> - }\n> -\n> if (qatomic_dec_fetch(&mon->suspend_cnt) == 0) {\n> AioContext *ctx;\n> \n> -- \n> 2.53.0\n>","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=treblig.org header.i=@treblig.org header.a=rsa-sha256\n header.s=bytemarkmx header.b=Lz5Z4CfO;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; 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