From patchwork Wed May 2 07:44:18 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Xu X-Patchwork-Id: 907362 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=208.118.235.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 40bVjs3z3wz9s21 for ; Wed, 2 May 2018 17:47:29 +1000 (AEST) Received: from localhost ([::1]:48193 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fDmU3-0004Hh-Dl for incoming@patchwork.ozlabs.org; Wed, 02 May 2018 03:47:27 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50187) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fDmRE-0002UR-FF for qemu-devel@nongnu.org; Wed, 02 May 2018 03:44:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fDmRD-00083Y-BW for qemu-devel@nongnu.org; Wed, 02 May 2018 03:44:32 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:40996 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 1fDmRD-00083D-7P for qemu-devel@nongnu.org; Wed, 02 May 2018 03:44:31 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C17DB84257 for ; Wed, 2 May 2018 07:44:30 +0000 (UTC) Received: from xz-mi.redhat.com (ovpn-12-111.pek2.redhat.com [10.72.12.111]) by smtp.corp.redhat.com (Postfix) with ESMTP id 352202141200; Wed, 2 May 2018 07:44:26 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Wed, 2 May 2018 15:44:18 +0800 Message-Id: <20180502074421.3762-2-peterx@redhat.com> In-Reply-To: <20180502074421.3762-1-peterx@redhat.com> References: <20180502074421.3762-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Wed, 02 May 2018 07:44:30 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Wed, 02 May 2018 07:44:30 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.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 v3 1/4] monitor: rename out_lock to mon_lock 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: Markus Armbruster , peterx@redhat.com, "Dr . David Alan Gilbert" , Stefan Hajnoczi , =?utf-8?q?Marc-Andr=C3=A9_Lureau?= Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" The out_lock was only protecting a few Monitor fields. In the future the monitor code will start to run in multiple threads. We turn it into a bigger lock to protect not only the out buffer but also all the rest. For now we share the lock. We can split the lock when needed. Since at it, arrange the Monitor struct a bit. Signed-off-by: Peter Xu --- monitor.c | 53 +++++++++++++++++++++++++++++------------------------ 1 file changed, 29 insertions(+), 24 deletions(-) diff --git a/monitor.c b/monitor.c index 39f8ee17ba..48882d28ae 100644 --- a/monitor.c +++ b/monitor.c @@ -207,15 +207,6 @@ struct Monitor { int suspend_cnt; /* Needs to be accessed atomically */ 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; - ReadLineState *rs; MonitorQMP qmp; gchar *mon_cpu_path; @@ -224,6 +215,20 @@ struct Monitor { 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. + */ + 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. */ @@ -366,14 +371,14 @@ 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; @@ -411,9 +416,9 @@ 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 */ @@ -421,7 +426,7 @@ 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') @@ -434,7 +439,7 @@ 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) @@ -728,7 +733,7 @@ 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. */ @@ -748,7 +753,7 @@ static void monitor_data_destroy(Monitor *mon) } readline_free(mon->rs); QDECREF(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); @@ -780,13 +785,13 @@ 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); @@ -4383,9 +4388,9 @@ 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); @@ -4405,9 +4410,9 @@ 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: From patchwork Wed May 2 07:44:19 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Xu X-Patchwork-Id: 907364 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=208.118.235.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 40bVk84Pgsz9s21 for ; Wed, 2 May 2018 17:47:44 +1000 (AEST) Received: from localhost ([::1]:48196 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fDmUI-0004Qf-J9 for incoming@patchwork.ozlabs.org; Wed, 02 May 2018 03:47:42 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50205) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fDmRI-0002YH-Lm for qemu-devel@nongnu.org; Wed, 02 May 2018 03:44:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fDmRH-00085x-Ov for qemu-devel@nongnu.org; Wed, 02 May 2018 03:44:36 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:40998 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 1fDmRH-00085j-Jk for qemu-devel@nongnu.org; Wed, 02 May 2018 03:44:35 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2F4ED7CBBA for ; Wed, 2 May 2018 07:44:35 +0000 (UTC) Received: from xz-mi.redhat.com (ovpn-12-111.pek2.redhat.com [10.72.12.111]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8F8252141200; Wed, 2 May 2018 07:44:31 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Wed, 2 May 2018 15:44:19 +0800 Message-Id: <20180502074421.3762-3-peterx@redhat.com> In-Reply-To: <20180502074421.3762-1-peterx@redhat.com> References: <20180502074421.3762-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Wed, 02 May 2018 07:44:35 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Wed, 02 May 2018 07:44:35 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.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 v3 2/4] monitor: protect mon->fds with mon_lock 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: Markus Armbruster , peterx@redhat.com, "Dr . David Alan Gilbert" , Stefan Hajnoczi , =?utf-8?q?Marc-Andr=C3=A9_Lureau?= Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" mon->fds were protected by BQL. Now protect it by mon_lock so that it can even be used in monitor iothread. Signed-off-by: Peter Xu --- monitor.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/monitor.c b/monitor.c index 48882d28ae..176d3ecc04 100644 --- a/monitor.c +++ b/monitor.c @@ -213,7 +213,6 @@ struct Monitor { BlockCompletionFunc *password_completion_cb; void *password_opaque; mon_cmd_t *cmd_table; - QLIST_HEAD(,mon_fd_t) fds; QTAILQ_ENTRY(Monitor) entry; /* @@ -225,6 +224,7 @@ struct Monitor { /* * 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. */ @@ -2207,6 +2207,7 @@ 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; @@ -2214,6 +2215,7 @@ void qmp_getfd(const char *fdname, Error **errp) close(monfd->fd); monfd->fd = fd; + qemu_mutex_unlock(&cur_mon->mon_lock); return; } @@ -2222,12 +2224,14 @@ 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; + qemu_mutex_lock(&cur_mon->mon_lock); QLIST_FOREACH(monfd, &cur_mon->fds, next) { if (strcmp(monfd->name, fdname) != 0) { continue; @@ -2237,9 +2241,11 @@ void qmp_closefd(const char *fdname, Error **errp) close(monfd->fd); g_free(monfd->name); g_free(monfd); + qemu_mutex_unlock(&cur_mon->mon_lock); return; } + qemu_mutex_unlock(&cur_mon->mon_lock); error_setg(errp, QERR_FD_NOT_FOUND, fdname); } @@ -2247,6 +2253,7 @@ int monitor_get_fd(Monitor *mon, const char *fdname, Error **errp) { mon_fd_t *monfd; + qemu_mutex_lock(&cur_mon->mon_lock); QLIST_FOREACH(monfd, &mon->fds, next) { int fd; @@ -2260,10 +2267,12 @@ 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(&cur_mon->mon_lock); return fd; } + qemu_mutex_unlock(&cur_mon->mon_lock); error_setg(errp, "File descriptor named '%s' has not been found", fdname); return -1; } From patchwork Wed May 2 07:44:20 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Xu X-Patchwork-Id: 907363 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=208.118.235.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 40bVjv757rz9s21 for ; Wed, 2 May 2018 17:47:31 +1000 (AEST) Received: from localhost ([::1]:48194 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fDmU5-0004Jb-SU for incoming@patchwork.ozlabs.org; Wed, 02 May 2018 03:47:29 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50238) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fDmRM-0002dZ-Vi for qemu-devel@nongnu.org; Wed, 02 May 2018 03:44:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fDmRM-00088Y-6K for qemu-devel@nongnu.org; Wed, 02 May 2018 03:44:40 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:41000 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 1fDmRM-00088I-1m for qemu-devel@nongnu.org; Wed, 02 May 2018 03:44:40 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 9291084257 for ; Wed, 2 May 2018 07:44:39 +0000 (UTC) Received: from xz-mi.redhat.com (ovpn-12-111.pek2.redhat.com [10.72.12.111]) by smtp.corp.redhat.com (Postfix) with ESMTP id E5EF72141200; Wed, 2 May 2018 07:44:35 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Wed, 2 May 2018 15:44:20 +0800 Message-Id: <20180502074421.3762-4-peterx@redhat.com> In-Reply-To: <20180502074421.3762-1-peterx@redhat.com> References: <20180502074421.3762-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Wed, 02 May 2018 07:44:39 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Wed, 02 May 2018 07:44:39 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.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 v3 3/4] monitor: more comments on lock-free fleids/funcs 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: Markus Armbruster , peterx@redhat.com, "Dr . David Alan Gilbert" , Stefan Hajnoczi , =?utf-8?q?Marc-Andr=C3=A9_Lureau?= Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Add some explicit comment for both Readline and cpu_set/cpu_get helpers that they do not need the mon_lock protection. Signed-off-by: Peter Xu --- monitor.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/monitor.c b/monitor.c index 176d3ecc04..38c50e06fc 100644 --- a/monitor.c +++ b/monitor.c @@ -207,6 +207,7 @@ struct Monitor { int suspend_cnt; /* Needs to be accessed atomically */ bool skip_flush; bool use_io_thr; + /* Only used in parser, so no lock needed. */ ReadLineState *rs; MonitorQMP qmp; gchar *mon_cpu_path; @@ -1316,7 +1317,7 @@ 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. BQL needed. */ int monitor_set_cpu(int cpu_index) { CPUState *cpu; @@ -1330,6 +1331,7 @@ int monitor_set_cpu(int cpu_index) return 0; } +/* BQL neeeded. */ static CPUState *mon_get_cpu_sync(bool synchronize) { CPUState *cpu; From patchwork Wed May 2 07:44:21 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Xu X-Patchwork-Id: 907365 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=208.118.235.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 40bVmk6Zmsz9s21 for ; Wed, 2 May 2018 17:49:58 +1000 (AEST) Received: from localhost ([::1]:48201 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fDmWS-00068a-Cj for incoming@patchwork.ozlabs.org; Wed, 02 May 2018 03:49:56 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50268) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fDmRS-0002ip-1Q for qemu-devel@nongnu.org; Wed, 02 May 2018 03:44:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fDmRQ-0008BS-Oa for qemu-devel@nongnu.org; Wed, 02 May 2018 03:44:46 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:41002 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 1fDmRQ-0008BB-IH for qemu-devel@nongnu.org; Wed, 02 May 2018 03:44:44 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1A3F78DC2E for ; Wed, 2 May 2018 07:44:44 +0000 (UTC) Received: from xz-mi.redhat.com (ovpn-12-111.pek2.redhat.com [10.72.12.111]) by smtp.corp.redhat.com (Postfix) with ESMTP id 60D792141200; Wed, 2 May 2018 07:44:39 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Wed, 2 May 2018 15:44:21 +0800 Message-Id: <20180502074421.3762-5-peterx@redhat.com> In-Reply-To: <20180502074421.3762-1-peterx@redhat.com> References: <20180502074421.3762-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Wed, 02 May 2018 07:44:44 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Wed, 02 May 2018 07:44:44 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.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 v3 4/4] monitor: add lock to protect mon_fdsets 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: Markus Armbruster , peterx@redhat.com, "Dr . David Alan Gilbert" , Stefan Hajnoczi , =?utf-8?q?Marc-Andr=C3=A9_Lureau?= Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Similar to previous patch, but introduce a new global big lock for mon_fdsets. Take it where needed. Signed-off-by: Peter Xu --- monitor.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 53 insertions(+), 11 deletions(-) diff --git a/monitor.c b/monitor.c index 38c50e06fc..03e52b4216 100644 --- a/monitor.c +++ b/monitor.c @@ -263,6 +263,9 @@ typedef struct QMPRequest QMPRequest; /* Protects mon_list, monitor_event_state. */ static QemuMutex monitor_lock; +/* Protects mon_fdsets */ +static QemuMutex mon_fdsets_lock; + static QTAILQ_HEAD(mon_list, Monitor) mon_list; static QLIST_HEAD(mon_fdsets, MonFdset) mon_fdsets; static int mon_refcount; @@ -279,6 +282,16 @@ static QEMUClockType event_clock_type = QEMU_CLOCK_REALTIME; static void monitor_command_cb(void *opaque, const char *cmdline, void *readline_opaque); +/* + * This lock can be used very early, even during param parsing. + * Meanwhile it can also be used even at the end of main. Let's keep + * it initialized for the whole lifecycle of QEMU. + */ +static void __attribute__((constructor)) mon_fdsets_lock_init(void) +{ + qemu_mutex_init(&mon_fdsets_lock); +} + /** * Is @mon a QMP monitor? */ @@ -2306,9 +2319,11 @@ 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, @@ -2343,6 +2358,7 @@ 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; @@ -2362,10 +2378,12 @@ 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); @@ -2381,6 +2399,7 @@ 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; @@ -2410,6 +2429,7 @@ FdsetInfoList *qmp_query_fdsets(Error **errp) fdset_info->next = fdset_list; fdset_list = fdset_info; } + qemu_mutex_unlock(&mon_fdsets_lock); return fdset_list; } @@ -2422,6 +2442,7 @@ 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 */ @@ -2442,6 +2463,7 @@ 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 */ @@ -2492,6 +2514,7 @@ 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; } @@ -2501,7 +2524,9 @@ int monitor_fdset_get_fd(int64_t fdset_id, int flags) MonFdset *mon_fdset; MonFdsetFd *mon_fdset_fd; int mon_fd_flags; + int ret = -1; + qemu_mutex_lock(&mon_fdsets_lock); QLIST_FOREACH(mon_fdset, &mon_fdsets, next) { if (mon_fdset->id != fdset_id) { continue; @@ -2509,49 +2534,62 @@ 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; + 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; + break; } -#endif - +out: + qemu_mutex_unlock(&mon_fdsets_lock); + return ret; +#else errno = ENOENT; return -1; +#endif } int monitor_fdset_dup_fd_add(int64_t fdset_id, int dup_fd) { MonFdset *mon_fdset; MonFdsetFd *mon_fdset_fd_dup; + int ret = -1; + 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; + ret = -1; + goto out; } } 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); - return 0; + ret = 0; + break; } - return -1; + +out: + qemu_mutex_unlock(&mon_fdsets_lock); + return ret; } static int monitor_fdset_dup_fd_find_remove(int dup_fd, bool remove) { MonFdset *mon_fdset; MonFdsetFd *mon_fdset_fd_dup; + int ret = -1; + 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) { @@ -2560,14 +2598,18 @@ 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; + ret = -1; + goto out; } else { - return mon_fdset->id; + ret = mon_fdset->id; + goto out; } } } } - return -1; +out: + qemu_mutex_unlock(&mon_fdsets_lock); + return ret; } int monitor_fdset_dup_fd_find(int dup_fd)