Patch Detail
get:
Show a patch.
patch:
Update a patch.
put:
Update a patch.
GET /api/patches/2195654/?format=api
{ "id": 2195654, "url": "http://patchwork.ozlabs.org/api/patches/2195654/?format=api", "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20260211152508.732487-20-berrange@redhat.com/", "project": { "id": 14, "url": "http://patchwork.ozlabs.org/api/projects/14/?format=api", "name": "QEMU Development", "link_name": "qemu-devel", "list_id": "qemu-devel.nongnu.org", "list_email": "qemu-devel@nongnu.org", "web_url": "", "scm_url": "", "webscm_url": "", "list_archive_url": "", "list_archive_url_format": "", "commit_url_format": "" }, "msgid": "<20260211152508.732487-20-berrange@redhat.com>", "list_archive_url": null, "date": "2026-02-11T15:25:00", "name": "[v6,19/27] util: fix interleaving of error & trace output", "commit_ref": null, "pull_url": null, "state": "new", "archived": false, "hash": "4863b96aa2b5d597584a5d635dbabc725d20761b", "submitter": { "id": 2694, "url": "http://patchwork.ozlabs.org/api/people/2694/?format=api", "name": "Daniel P. Berrangé", "email": "berrange@redhat.com" }, "delegate": null, "mbox": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20260211152508.732487-20-berrange@redhat.com/mbox/", "series": [ { "id": 491862, "url": "http://patchwork.ozlabs.org/api/series/491862/?format=api", "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/list/?series=491862", "date": "2026-02-11T15:24:41", "name": "util: sync error_report & qemu_log output more closely", "version": 6, "mbox": "http://patchwork.ozlabs.org/series/491862/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/patches/2195654/comments/", "check": "pending", "checks": "http://patchwork.ozlabs.org/api/patches/2195654/checks/", "tags": {}, "related": [], "headers": { "Return-Path": "<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>", "X-Original-To": "incoming@patchwork.ozlabs.org", "Delivered-To": "patchwork-incoming@legolas.ozlabs.org", "Authentication-Results": [ "legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256\n header.s=mimecast20190719 header.b=VclvwwfB;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; helo=lists.gnu.org;\n envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n receiver=patchwork.ozlabs.org)" ], "Received": [ "from lists.gnu.org (lists.gnu.org [209.51.188.17])\n\t(using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fB2V04yMZz1xpY\n\tfor <incoming@patchwork.ozlabs.org>; Thu, 12 Feb 2026 02:31:52 +1100 (AEDT)", "from localhost ([::1] helo=lists1p.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.90_1)\n\t(envelope-from <qemu-devel-bounces@nongnu.org>)\n\tid 1vqC7m-0007uu-SY; Wed, 11 Feb 2026 10:27:30 -0500", "from eggs.gnu.org ([2001:470:142:3::10])\n by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from <berrange@redhat.com>)\n id 1vqC7Y-00073v-0k\n for qemu-devel@nongnu.org; Wed, 11 Feb 2026 10:27:16 -0500", "from us-smtp-delivery-124.mimecast.com ([170.10.133.124])\n by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from <berrange@redhat.com>)\n id 1vqC7U-00064K-Pz\n for qemu-devel@nongnu.org; Wed, 11 Feb 2026 10:27:15 -0500", "from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com\n (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by\n relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3,\n cipher=TLS_AES_256_GCM_SHA384) id us-mta-98-s9KGedNhOS2bf2mYapvZ5A-1; Wed,\n 11 Feb 2026 10:27:06 -0500", "from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com\n (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4])\n (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest\n SHA256)\n (No client certificate requested)\n by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS\n id CD4701955F1D; Wed, 11 Feb 2026 15:27:04 +0000 (UTC)", "from toolbx.redhat.com (unknown [10.45.227.9])\n by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP\n id D3DA230001A8; Wed, 11 Feb 2026 15:26:59 +0000 (UTC)" ], "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com;\n s=mimecast20190719; t=1770823632;\n h=from:from:reply-to:subject:subject:date:date:message-id:message-id:\n to:to:cc:cc:mime-version:mime-version:content-type:content-type:\n content-transfer-encoding:content-transfer-encoding:\n in-reply-to:in-reply-to:references:references;\n bh=RAw0M5DQrWvr04qhs1mJQ/D6Qx2tWsXmBnfqMP/fRAg=;\n b=VclvwwfBDjvsU4OXByDEnODhG4UJgiaaynlsj/jWEZlUTpJjIP7GbYj/vaZM6JkrDx5b2O\n RXexJ2PSCus7S1P4IsVDxh7U7OxdNf8JGgFGjb9aRGMM+AmozSf5w7H0/aL8TC2D+MfWuc\n ARVbgCR7fmbEJfeY1nF05t/nkRNzcWc=", "X-MC-Unique": "s9KGedNhOS2bf2mYapvZ5A-1", "X-Mimecast-MFC-AGG-ID": "s9KGedNhOS2bf2mYapvZ5A_1770823624", "From": "=?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= <berrange@redhat.com>", "To": "qemu-devel@nongnu.org", "Cc": "Manos Pitsidianakis <manos.pitsidianakis@linaro.org>,\n Stefan Weil <sw@weilnetz.de>, \"Dr. David Alan Gilbert\" <dave@treblig.org>,\n Pierrick Bouvier <pierrick.bouvier@linaro.org>, devel@lists.libvirt.org,\n\t=?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= <philmd@linaro.org>, =?utf-8?q?Marc?=\n\t=?utf-8?q?-Andr=C3=A9_Lureau?= <marcandre.lureau@redhat.com>,\n Hanna Reitz <hreitz@redhat.com>, Kevin Wolf <kwolf@redhat.com>,\n qemu-block@nongnu.org, qemu-rust@nongnu.org,\n Paolo Bonzini <pbonzini@redhat.com>, Markus Armbruster <armbru@redhat.com>,\n Gerd Hoffmann <kraxel@redhat.com>,\n =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= <berrange@redhat.com>,\n Christian Schoenebeck <qemu_oss@crudebyte.com>,\n Richard Henderson <richard.henderson@linaro.org>", "Subject": "[PATCH v6 19/27] util: fix interleaving of error & trace output", "Date": "Wed, 11 Feb 2026 15:25:00 +0000", "Message-ID": "<20260211152508.732487-20-berrange@redhat.com>", "In-Reply-To": "<20260211152508.732487-1-berrange@redhat.com>", "References": "<20260211152508.732487-1-berrange@redhat.com>", "MIME-Version": "1.0", "Content-Type": "text/plain; charset=UTF-8", "Content-Transfer-Encoding": "8bit", "X-Scanned-By": "MIMEDefang 3.4.1 on 10.30.177.4", "Received-SPF": "pass client-ip=170.10.133.124;\n envelope-from=berrange@redhat.com;\n helo=us-smtp-delivery-124.mimecast.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, DKIMWL_WL_HIGH=-0.001,\n DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1,\n RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=0.001,\n RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001,\n SPF_HELO_PASS=-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": "2.1.29", "Precedence": "list", "List-Id": "qemu development <qemu-devel.nongnu.org>", "List-Unsubscribe": "<https://lists.nongnu.org/mailman/options/qemu-devel>,\n <mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>", "List-Archive": "<https://lists.nongnu.org/archive/html/qemu-devel>", "List-Post": "<mailto:qemu-devel@nongnu.org>", "List-Help": "<mailto:qemu-devel-request@nongnu.org?subject=help>", "List-Subscribe": "<https://lists.nongnu.org/mailman/listinfo/qemu-devel>,\n <mailto:qemu-devel-request@nongnu.org?subject=subscribe>", "Errors-To": "qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org", "Sender": "qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org" }, "content": "The monitor_cur_hmp() function will acquire/release mutex locks, which\nwill trigger trace probes, which can in turn trigger qemu_log() calls.\nvreport() calls monitor_cur() multiple times through its execution\nboth directly and indirectly via error_vprintf().\n\nThe result is that the prefix information printed by vreport() gets\ninterleaved with qemu_log() output, when run outside the context of\nan HMP command dispatcher. This can be seen with:\n\n $ qemu-system-x86_64 \\\n -msg timestamp=on,guest-name=on \\\n -display none \\\n -object tls-creds-x509,id=f,dir=fish \\\n -name fish \\\n -d trace:qemu_mutex*\n 2025-09-10T16:30:42.514374Z qemu_mutex_unlock released mutex 0x560b0339b4c0 (/var/home/berrange/src/virt/qemu/include/qemu/lockable.h:56)\n 2025-09-10T16:30:42.514400Z qemu_mutex_lock waiting on mutex 0x560b033983e0 (/var/home/berrange/src/virt/qemu/include/qemu/lockable.h:56)\n 2025-09-10T16:30:42.514402Z qemu_mutex_locked taken mutex 0x560b033983e0 (/var/home/berrange/src/virt/qemu/include/qemu/lockable.h:56)\n 2025-09-10T16:30:42.514404Z qemu_mutex_unlock released mutex 0x560b033983e0 (/var/home/berrange/src/virt/qemu/include/qemu/lockable.h:56)\n 2025-09-10T16:30:42.516716Z qemu_mutex_lock waiting on mutex 0x560b03398560 (../monitor/monitor.c:91)\n 2025-09-10T16:30:42.516723Z qemu_mutex_locked taken mutex 0x560b03398560 (../monitor/monitor.c:91)\n 2025-09-10T16:30:42.516726Z qemu_mutex_unlock released mutex 0x560b03398560 (../monitor/monitor.c:96)\n 2025-09-10T16:30:42.516728Z qemu_mutex_lock waiting on mutex 0x560b03398560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:04.842057Z qemu_mutex_locked taken mutex 0x564f5e401560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:04.842058Z qemu_mutex_unlock released mutex 0x564f5e401560 (../monitor/monitor.c:96)\n 2025-09-10T16:31:04.842055Z 2025-09-10T16:31:04.842060Z qemu_mutex_lock waiting on mutex 0x564f5e401560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:04.842061Z qemu_mutex_locked taken mutex 0x564f5e401560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:04.842062Z qemu_mutex_unlock released mutex 0x564f5e401560 (../monitor/monitor.c:96)\n 2025-09-10T16:31:04.842064Z qemu_mutex_lock waiting on mutex 0x564f5e401560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:04.842065Z qemu_mutex_locked taken mutex 0x564f5e401560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:04.842066Z qemu_mutex_unlock released mutex 0x564f5e401560 (../monitor/monitor.c:96)\n fish 2025-09-10T16:31:04.842068Z qemu_mutex_lock waiting on mutex 0x564f5e401560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:04.842069Z qemu_mutex_locked taken mutex 0x564f5e401560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:04.842070Z qemu_mutex_unlock released mutex 0x564f5e401560 (../monitor/monitor.c:96)\n 2025-09-10T16:31:04.842072Z qemu_mutex_lock waiting on mutex 0x564f5e401560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:04.842097Z qemu_mutex_locked taken mutex 0x564f5e401560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:04.842099Z qemu_mutex_unlock released mutex 0x564f5e401560 (../monitor/monitor.c:96)\n qemu-system-x86_64:2025-09-10T16:31:04.842100Z qemu_mutex_lock waiting on mutex 0x564f5e401560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:04.842102Z qemu_mutex_locked taken mutex 0x564f5e401560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:04.842103Z qemu_mutex_unlock released mutex 0x564f5e401560 (../monitor/monitor.c:96)\n 2025-09-10T16:31:04.842105Z qemu_mutex_lock waiting on mutex 0x564f5e401560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:04.842106Z qemu_mutex_locked taken mutex 0x564f5e401560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:04.842107Z qemu_mutex_unlock released mutex 0x564f5e401560 (../monitor/monitor.c:96)\n Unable to access credentials fish/ca-cert.pem: No such file or directory2025-09-10T16:31:04.842109Z qemu_mutex_lock waiting on mutex 0x564f5e401560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:04.842110Z qemu_mutex_locked taken mutex 0x564f5e401560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:04.842111Z qemu_mutex_unlock released mutex 0x564f5e401560 (../monitor/monitor.c:96)\n\nTo avoid this interleaving (as well as reduce the huge number of\nmutex lock/unlock calls) we need to ensure that monitor_cur_is_hmp()\nis only called once at the start of vreport(), and if no HMP is\npresent, no further monitor APIs can be called.\n\nThis implies error_[v]printf() cannot be called from vreport().\nInstead we must introduce error_[v]printf_mon() which accept a\npre-acquired Monitor object. In some cases, however, fprintf\ncan be called directly as output will never be directed to the\nmonitor.\n\n $ qemu-system-x86_64 \\\n -msg timestamp=on,guest-name=on \\\n -display none \\\n -object tls-creds-x509,id=f,dir=fish \\\n -name fish \\\n -d trace:qemu_mutex*\n 2025-09-10T16:31:22.701691Z qemu_mutex_unlock released mutex 0x5626fd3b84c0 (/var/home/berrange/src/virt/qemu/include/qemu/lockable.h:56)\n 2025-09-10T16:31:22.701728Z qemu_mutex_lock waiting on mutex 0x5626fd3b53e0 (/var/home/berrange/src/virt/qemu/include/qemu/lockable.h:56)\n 2025-09-10T16:31:22.701730Z qemu_mutex_locked taken mutex 0x5626fd3b53e0 (/var/home/berrange/src/virt/qemu/include/qemu/lockable.h:56)\n 2025-09-10T16:31:22.701732Z qemu_mutex_unlock released mutex 0x5626fd3b53e0 (/var/home/berrange/src/virt/qemu/include/qemu/lockable.h:56)\n 2025-09-10T16:31:22.703989Z qemu_mutex_lock waiting on mutex 0x5626fd3b5560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:22.703996Z qemu_mutex_locked taken mutex 0x5626fd3b5560 (../monitor/monitor.c:91)\n 2025-09-10T16:31:22.703999Z qemu_mutex_unlock released mutex 0x5626fd3b5560 (../monitor/monitor.c:96)\n 2025-09-10T16:31:22.704000Z fish qemu-system-x86_64: Unable to access credentials fish/ca-cert.pem: No such file or directory\n\nReviewed-by: Richard Henderson <richard.henderson@linaro.org>\nSigned-off-by: Daniel P. Berrangé <berrange@redhat.com>\n---\n util/error-report.c | 63 ++++++++++++++++++++++++++++++---------------\n 1 file changed, 42 insertions(+), 21 deletions(-)", "diff": "diff --git a/util/error-report.c b/util/error-report.c\nindex f3aa24ec22..b34a2bc7bc 100644\n--- a/util/error-report.c\n+++ b/util/error-report.c\n@@ -32,9 +32,9 @@ const char *error_guest_name;\n /*\n * Print to the current human monitor if we have one, else to stderr.\n */\n-int error_vprintf(const char *fmt, va_list ap)\n+static int G_GNUC_PRINTF(2, 0)\n+error_vprintf_mon(Monitor *cur_mon, const char *fmt, va_list ap)\n {\n- Monitor *cur_mon = monitor_cur();\n /*\n * This will return -1 if 'cur_mon' is NULL, or is QMP.\n * IOW this will only print if in HMP, otherwise we\n@@ -47,13 +47,33 @@ int error_vprintf(const char *fmt, va_list ap)\n return ret;\n }\n \n+/*\n+ * Print to the current human monitor if we have one, else to stderr.\n+ */\n+static int G_GNUC_PRINTF(2, 3)\n+error_printf_mon(Monitor *cur_mon, const char *fmt, ...)\n+{\n+ va_list ap;\n+ int ret;\n+\n+ va_start(ap, fmt);\n+ ret = error_vprintf_mon(cur_mon, fmt, ap);\n+ va_end(ap);\n+ return ret;\n+}\n+\n+int error_vprintf(const char *fmt, va_list ap)\n+{\n+ return error_vprintf_mon(monitor_cur(), fmt, ap);\n+}\n+\n int error_printf(const char *fmt, ...)\n {\n va_list ap;\n int ret;\n \n va_start(ap, fmt);\n- ret = error_vprintf(fmt, ap);\n+ ret = error_vprintf_mon(monitor_cur(), fmt, ap);\n va_end(ap);\n return ret;\n }\n@@ -156,34 +176,34 @@ void loc_set_file(const char *fname, int lno)\n /*\n * Print current location to current monitor if we have one, else to stderr.\n */\n-static void print_loc(void)\n+static void print_loc(Monitor *cur)\n {\n const char *sep = \"\";\n int i;\n const char *const *argp;\n \n- if (!monitor_cur() && g_get_prgname()) {\n- error_printf(\"%s:\", g_get_prgname());\n+ if (!cur && g_get_prgname()) {\n+ fprintf(stderr, \"%s:\", g_get_prgname());\n sep = \" \";\n }\n switch (cur_loc->kind) {\n case LOC_CMDLINE:\n argp = cur_loc->ptr;\n for (i = 0; i < cur_loc->num; i++) {\n- error_printf(\"%s%s\", sep, argp[i]);\n+ error_printf_mon(cur, \"%s%s\", sep, argp[i]);\n sep = \" \";\n }\n- error_printf(\": \");\n+ error_printf_mon(cur, \": \");\n break;\n case LOC_FILE:\n- error_printf(\"%s:\", (const char *)cur_loc->ptr);\n+ error_printf_mon(cur, \"%s:\", (const char *)cur_loc->ptr);\n if (cur_loc->num) {\n- error_printf(\"%d:\", cur_loc->num);\n+ error_printf_mon(cur, \"%d:\", cur_loc->num);\n }\n- error_printf(\" \");\n+ error_printf_mon(cur, \" \");\n break;\n default:\n- error_printf(\"%s\", sep);\n+ error_printf_mon(cur, \"%s\", sep);\n }\n }\n \n@@ -204,34 +224,35 @@ real_time_iso8601(void)\n G_GNUC_PRINTF(2, 0)\n static void vreport(report_type type, const char *fmt, va_list ap)\n {\n+ Monitor *cur = monitor_cur();\n gchar *timestr;\n \n- if (message_with_timestamp && !monitor_cur()) {\n+ if (message_with_timestamp && !cur) {\n timestr = real_time_iso8601();\n- error_printf(\"%s \", timestr);\n+ fprintf(stderr, \"%s \", timestr);\n g_free(timestr);\n }\n \n /* Only prepend guest name if -msg guest-name and -name guest=... are set */\n- if (error_with_guestname && error_guest_name && !monitor_cur()) {\n- error_printf(\"%s \", error_guest_name);\n+ if (error_with_guestname && error_guest_name && !cur) {\n+ fprintf(stderr, \"%s \", error_guest_name);\n }\n \n- print_loc();\n+ print_loc(cur);\n \n switch (type) {\n case REPORT_TYPE_ERROR:\n break;\n case REPORT_TYPE_WARNING:\n- error_printf(\"warning: \");\n+ error_printf_mon(cur, \"warning: \");\n break;\n case REPORT_TYPE_INFO:\n- error_printf(\"info: \");\n+ error_printf_mon(cur, \"info: \");\n break;\n }\n \n- error_vprintf(fmt, ap);\n- error_printf(\"\\n\");\n+ error_vprintf_mon(cur, fmt, ap);\n+ error_printf_mon(cur, \"\\n\");\n }\n \n /*\n", "prefixes": [ "v6", "19/27" ] }