From patchwork Fri Jul 9 16:08:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Zhang X-Patchwork-Id: 1503292 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=IslzJIJT; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4GLzLD3Wg9z9sPf for ; Sat, 10 Jul 2021 02:35:48 +1000 (AEST) Received: from localhost ([::1]:43048 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m1tTe-0004Hu-8T for incoming@patchwork.ozlabs.org; Fri, 09 Jul 2021 12:35:46 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37882) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m1t6a-0004Hg-CP for qemu-devel@nongnu.org; Fri, 09 Jul 2021 12:11:56 -0400 Received: from mail-wr1-x434.google.com ([2a00:1450:4864:20::434]:35763) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1m1t6W-0001iy-Ks for qemu-devel@nongnu.org; Fri, 09 Jul 2021 12:11:56 -0400 Received: by mail-wr1-x434.google.com with SMTP id m2so1822301wrq.2 for ; Fri, 09 Jul 2021 09:11:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=4SfwWmdkOVCkT/IbHrk454t5eodPaV5xA4orcSAa8bA=; b=IslzJIJTCPMhRZsg/fk/DvbV0xDmrnCmJrO0P8bn0sMKA7pxkP3+LXo+tSSpK+QBUj LZbc389LU2F7gacnQ8kSJOMYR83VOMADVzKh0//96V8PqH2dEe2tvmSRD24uzH2SlzJC bC3Z69xpXX/JYOSJOc9d+eo7yTYI0yqjnfO/pKqZGSGQ4urOvCk/8HmbvsEPMxj7B2Av kuaAEg6o6N47893N+ac6NCby9uOj22tPusuxUIzLe4cRUXQAOGBuZ2+CpHqdRtjkgesK JMY3v8Qtn9sarkqhalQXwJPNnnbqPK0mwNoH/3DcIEXR4pC+/6aYDdrRw7n68L5nCpgx kouQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=4SfwWmdkOVCkT/IbHrk454t5eodPaV5xA4orcSAa8bA=; b=ufkOs/6OC+5N5uTXG4a1cKEBo5DlJw5tiylJu5v6y+6+p19f2KWpk+wFGCltC/YoMA zXCk7WhY9iyXhBw5gK9udZX8gvzj3P7oHQUBsUdD+dQ5Kq2fLGxfrv8QNobu/h8dHd3X AFYpAZRKS3oQeKQdQTMjSGZQMBCFztfATHK0FdOR3pX0vvMPseLevNT8e82Qf2YXOVlX u7nRmhGaCH3idrPoMpWgOVOd51khLzEousxJzQKxx4A2yZkFmHMNbrZZiQP2hJpSvaNu c8jiybb0M+G9A7u3pDWNqtBo6lBL2rSCjsj5OS3M3VmsHIISLoX4HKC9qrikgzMvzqBx 5QIQ== X-Gm-Message-State: AOAM5320i37JRfbi6Bjj0zm31zMI7ibt4UzSmxpWDaM/esnf8IHmbx/3 8he39pl4aQmQr00/k4cbpcA= X-Google-Smtp-Source: ABdhPJyXstOWgs+WigIqKz6LZjvb6yx6zWNGbjnOy9F6R8MCBbh4oO9DT0uyd9YdSlIwI4eyhVYByw== X-Received: by 2002:a05:6000:511:: with SMTP id a17mr42731581wrf.351.1625847110074; Fri, 09 Jul 2021 09:11:50 -0700 (PDT) Received: from lb01556.speedport.ip ([2003:f1:1706:da4a:4a24:a8e2:ab18:53c]) by smtp.gmail.com with ESMTPSA id h15sm5652360wrq.88.2021.07.09.09.11.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Jul 2021 09:11:49 -0700 (PDT) From: Li Zhang X-Google-Original-From: Li Zhang To: armbru@redhat.com, marcandre.lureau@gmail.com, pankaj.gupta@ionos.com, qemu-devel@nongnu.org Subject: [PATCH v3 RESEND 1/2] qmp: Support chardev-change Date: Fri, 9 Jul 2021 18:08:42 +0200 Message-Id: <20210709160843.339796-1-li.zhang@ionos.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Received-SPF: pass client-ip=2a00:1450:4864:20::434; envelope-from=zhlcindy@gmail.com; helo=mail-wr1-x434.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Li Zhang Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" For some scenarios, we'd like to hot-add a monitor device. But QEMU doesn't support that, yet. It does support hot-swapping character backends with QMP command chardev-change. This lets us pre-add a monitor with a null character backend, then chardev-change to a socket backend. Except the chardev-change fails with "Chardev user does not support chardev hotswap" because monitors don't provide the required callback. Implement it for QMP monitors. Signed-off-by: Li Zhang --- v3 -> v2: * Rework the patch which is to add hotswap for QMP device https://lists.nongnu.org/archive/html/qemu-devel/2021-04/msg03167.html * Refactor the functions qmp_chardev_add and qmp_chardev_change monitor/monitor-internal.h | 1 + monitor/monitor.c | 4 +- monitor/qmp.c | 84 +++++++++++++++++++++++++++----------- 3 files changed, 63 insertions(+), 26 deletions(-) diff --git a/monitor/monitor-internal.h b/monitor/monitor-internal.h index 9c3a09cb01..162f73119b 100644 --- a/monitor/monitor-internal.h +++ b/monitor/monitor-internal.h @@ -182,5 +182,6 @@ int get_monitor_def(Monitor *mon, int64_t *pval, const char *name); void help_cmd(Monitor *mon, const char *name); void handle_hmp_command(MonitorHMP *mon, const char *cmdline); int hmp_compare_cmd(const char *name, const char *list); +void monitor_flush_locked(Monitor *mon); #endif diff --git a/monitor/monitor.c b/monitor/monitor.c index b90c0f4051..1b05ef3bdb 100644 --- a/monitor/monitor.c +++ b/monitor/monitor.c @@ -154,8 +154,6 @@ static inline bool monitor_is_hmp_non_interactive(const Monitor *mon) return !monitor_uses_readline(container_of(mon, MonitorHMP, common)); } -static void monitor_flush_locked(Monitor *mon); - static gboolean monitor_unblocked(GIOChannel *chan, GIOCondition cond, void *opaque) { @@ -169,7 +167,7 @@ static gboolean monitor_unblocked(GIOChannel *chan, GIOCondition cond, } /* Caller must hold mon->mon_lock */ -static void monitor_flush_locked(Monitor *mon) +void monitor_flush_locked(Monitor *mon) { int rc; size_t len; diff --git a/monitor/qmp.c b/monitor/qmp.c index 092c527b6f..29b49ee041 100644 --- a/monitor/qmp.c +++ b/monitor/qmp.c @@ -46,6 +46,8 @@ struct QMPRequest { typedef struct QMPRequest QMPRequest; QmpCommandList qmp_commands, qmp_cap_negotiation_commands; +static void monitor_qmp_setup_handlers_bh(void *opaque); +static void monitor_backend_init(MonitorQMP *mon, Chardev *chr); static bool qmp_oob_enabled(MonitorQMP *mon) { @@ -481,6 +483,35 @@ void monitor_data_destroy_qmp(MonitorQMP *mon) g_queue_free(mon->qmp_requests); } +static bool monitor_in_list(Monitor *mon) +{ + Monitor *mon_tmp; + QTAILQ_FOREACH(mon_tmp, &mon_list, entry) { + if (mon_tmp == mon) { + return true; + } + } + return false; +} + +static int monitor_qmp_change(void *opaque) +{ + MonitorQMP *mon = opaque; + + monitor_data_init(&mon->common, true, false, + qemu_chr_has_feature(mon->common.chr.chr, + QEMU_CHAR_FEATURE_GCONTEXT)); + monitor_backend_init(mon, mon->common.chr.chr); + qemu_mutex_lock(&mon->common.mon_lock); + if (mon->common.out_watch) { + mon->common.out_watch = 0; + monitor_flush_locked(&mon->common); + } + qemu_mutex_unlock(&mon->common.mon_lock); + + return 0; +} + static void monitor_qmp_setup_handlers_bh(void *opaque) { MonitorQMP *mon = opaque; @@ -491,30 +522,15 @@ static void monitor_qmp_setup_handlers_bh(void *opaque) 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); -} + monitor_qmp_change, &mon->common, context, true); -void monitor_init_qmp(Chardev *chr, bool pretty, Error **errp) -{ - MonitorQMP *mon = g_new0(MonitorQMP, 1); - - if (!qemu_chr_fe_init(&mon->common.chr, chr, errp)) { - g_free(mon); - return; + if (!monitor_in_list(&mon->common)) { + monitor_list_append(&mon->common); } - qemu_chr_fe_set_echo(&mon->common.chr, true); - - /* Note: we run QMP monitor in I/O thread when @chr supports that */ - monitor_data_init(&mon->common, true, false, - qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_GCONTEXT)); - - mon->pretty = pretty; - - qemu_mutex_init(&mon->qmp_queue_lock); - mon->qmp_requests = g_queue_new(); +} - json_message_parser_init(&mon->parser, handle_qmp_command, mon, NULL); +static void monitor_backend_init(MonitorQMP *mon, Chardev *chr) +{ if (mon->common.use_io_thread) { /* * Make sure the old iowatch is gone. It's possible when @@ -532,7 +548,29 @@ void monitor_init_qmp(Chardev *chr, bool pretty, Error **errp) } 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); + monitor_qmp_change, &mon->common, NULL, true); + if (!monitor_in_list(&mon->common)) { + monitor_list_append(&mon->common); + } } } + +void monitor_init_qmp(Chardev *chr, bool pretty, Error **errp) +{ + MonitorQMP *mon = g_new0(MonitorQMP, 1); + + if (!qemu_chr_fe_init(&mon->common.chr, chr, errp)) { + g_free(mon); + return; + } + qemu_chr_fe_set_echo(&mon->common.chr, true); + /* Note: we run QMP monitor in I/O thread when @chr supports that */ + monitor_data_init(&mon->common, true, false, + qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_GCONTEXT)); + + mon->pretty = pretty; + qemu_mutex_init(&mon->qmp_queue_lock); + mon->qmp_requests = g_queue_new(); + json_message_parser_init(&mon->parser, handle_qmp_command, mon, NULL); + monitor_backend_init(mon, chr); +}