From nobody Mon Feb 9 02:27:46 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1520586565161405.1503689448789; Fri, 9 Mar 2018 01:09:25 -0800 (PST) Received: from localhost ([::1]:43901 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1euE1g-0005kn-0f for importer@patchew.org; Fri, 09 Mar 2018 04:09:20 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41816) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1euDu8-0008GW-3Z for qemu-devel@nongnu.org; Fri, 09 Mar 2018 04:01:34 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1euDu4-0008H6-5z for qemu-devel@nongnu.org; Fri, 09 Mar 2018 04:01:32 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:60284 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1euDu4-0008Gs-0E for qemu-devel@nongnu.org; Fri, 09 Mar 2018 04:01:28 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7B8828151D49; Fri, 9 Mar 2018 09:01:27 +0000 (UTC) Received: from xz-mi.redhat.com (ovpn-12-92.pek2.redhat.com [10.72.12.92]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4E298202322A; Fri, 9 Mar 2018 09:01:22 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Fri, 9 Mar 2018 16:59:56 +0800 Message-Id: <20180309090006.10018-14-peterx@redhat.com> In-Reply-To: <20180309090006.10018-1-peterx@redhat.com> References: <20180309090006.10018-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Fri, 09 Mar 2018 09:01:27 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Fri, 09 Mar 2018 09:01:27 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'peterx@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH v8 13/23] monitor: let suspend/resume work even with QMPs X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Laurent Vivier , Fam Zheng , Juan Quintela , mdroth@linux.vnet.ibm.com, peterx@redhat.com, Markus Armbruster , marcandre.lureau@redhat.com, Stefan Hajnoczi , Paolo Bonzini , "Dr . David Alan Gilbert" Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" This patches allows QMP monitors to be suspended/resumed. One thing to mention is that for QMPs that are using IOThreads, we need an explicit kick for the IOThread in case it is sleeping. Meanwhile, we need to take special care on non-interactive HMPs. Currently only gdbserver is using that. For these monitors, we still don't allow suspend/resume operations. Since at it, add traces for the operations. Signed-off-by: Peter Xu Reviewed-by: Eric Blake --- monitor.c | 47 ++++++++++++++++++++++++++++++++++++++++++++--- trace-events | 1 + 2 files changed, 45 insertions(+), 3 deletions(-) diff --git a/monitor.c b/monitor.c index 71b696c8f3..de9343be87 100644 --- a/monitor.c +++ b/monitor.c @@ -250,6 +250,21 @@ static inline bool monitor_is_qmp(const Monitor *mon) return (mon->flags & MONITOR_USE_CONTROL); } =20 +/** + * Whether @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); +} + /** * Is the current monitor, if any, a QMP monitor? */ @@ -3946,19 +3961,45 @@ static void monitor_command_cb(void *opaque, const = char *cmdline, =20 int monitor_suspend(Monitor *mon) { - if (!mon->rs) + if (monitor_is_hmp_non_interactive(mon)) { return -ENOTTY; + } + atomic_inc(&mon->suspend_cnt); + + if (monitor_is_qmp(mon)) { + /* + * Kick iothread to make sure this takes effect. It'll be + * evaluated again in prepare() of the watch object. + */ + aio_notify(iothread_get_aio_context(mon_global.mon_iothread)); + } + + trace_monitor_suspend(mon, 1); return 0; } =20 void monitor_resume(Monitor *mon) { - if (!mon->rs) + if (monitor_is_hmp_non_interactive(mon)) { return; + } + if (atomic_dec_fetch(&mon->suspend_cnt) =3D=3D 0) { - readline_show_prompt(mon->rs); + if (monitor_is_qmp(mon)) { + /* + * For QMP monitors that are running in IOThread, let's + * kick the thread in case it's sleeping. + */ + if (mon->use_io_thr) { + aio_notify(iothread_get_aio_context(mon_global.mon_iothrea= d)); + } + } else { + assert(mon->rs); + readline_show_prompt(mon->rs); + } } + trace_monitor_suspend(mon, -1); } =20 static QObject *get_qmp_greeting(Monitor *mon) diff --git a/trace-events b/trace-events index 89fcad0fd1..fe10c3b487 100644 --- a/trace-events +++ b/trace-events @@ -47,6 +47,7 @@ monitor_protocol_event_emit(uint32_t event, void *data) "= event=3D%d data=3D%p" monitor_protocol_event_queue(uint32_t event, void *qdict, uint64_t rate) "= event=3D%d data=3D%p rate=3D%" PRId64 handle_hmp_command(void *mon, const char *cmdline) "mon %p cmdline: %s" handle_qmp_command(void *mon, const char *req) "mon %p req: %s" +monitor_suspend(void *ptr, int cnt) "mon %p: %d" =20 # dma-helpers.c dma_blk_io(void *dbs, void *bs, int64_t offset, bool to_dev) "dbs=3D%p bs= =3D%p offset=3D%" PRId64 " to_dev=3D%d" --=20 2.14.3