From patchwork Mon Dec 28 14:58:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Lukas Straub X-Patchwork-Id: 11991259 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A0F9C433DB for ; Mon, 28 Dec 2020 15:00:22 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id B2150208D5 for ; Mon, 28 Dec 2020 15:00:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B2150208D5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=web.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:57082 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ktu0S-00042r-EG for qemu-devel@archiver.kernel.org; Mon, 28 Dec 2020 10:00:20 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:47654) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kttyq-0002SE-9s; Mon, 28 Dec 2020 09:58:40 -0500 Received: from mout.web.de ([212.227.15.4]:50653) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kttyo-0006RY-8M; Mon, 28 Dec 2020 09:58:39 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=dbaedf251592; t=1609167512; bh=466+q48hDaQZDo9a1KN15mfyI8EsaHW1PIwMSrcAojo=; h=X-UI-Sender-Class:Date:From:To:Cc:Subject; b=ez7dLT9nWY+x7XLdyriiSu4Pp21mDVL3BQOubk1J5XqbHVXb6fW1YOXRygb2Tr+Km Gjck0h5Srx2mtDRjDZCNXpTrO+sZIJLHlSHAjtj8Kft1us6Z5Fo5L1tMGtVQEh92Z0 QrMysxrQMDxxh+WfHYZ5NTfgitoOZch94+T4WlyU= X-UI-Sender-Class: c548c8c5-30a9-4db5-a2e7-cb6cb037b8f9 Received: from gecko.fritz.box ([94.134.180.94]) by smtp.web.de (mrweb005 [213.165.67.108]) with ESMTPSA (Nemesis) id 1MK52w-1kbhAf3rZO-00Luju; Mon, 28 Dec 2020 15:58:32 +0100 Date: Mon, 28 Dec 2020 15:58:21 +0100 From: Lukas Straub To: qemu-devel Subject: [PATCH v13 0/7] Introduce 'yank' oob qmp command to recover from hanging qemu Message-ID: MIME-Version: 1.0 X-Provags-ID: V03:K1:IZDpoLqjycGa2Vp2N6tPcMHiemrcGBzVKngsv5GXW1otyVlrhr5 yLzAT84+rKXt2VnYIEJBZ/AjUEnlw08s60OhzI72HOfOTR3/usVMRKlPuv5kuTGiYaPJaNR qhb5Z/pOfPo5f06vU/vfzHakIDCsDSiLGsRx5naRwmi9gk2qEVs8j+Uu65/lPuDIcP90jnc FI7R/wghFiby2XCQKSb5w== X-UI-Out-Filterresults: notjunk:1;V03:K0:5hrpdfyJ6rA=:7dryWqde1Io6VXEgjWHKpA hMltaEzfqBcDOQOomrTzheGUMM2bvoUjBhWm3JCnNs8B3FvM4Hlx/7ApmsYoMzFwNQz9iH/Fy xlLJVAhA0l5nICstGUShrOQs4UXzaka5iQOK9a0O01vcC3mkZj2QjEeVU0XfEhu/dqWC4U40y WpkCDlyG4/Pla/U979aRSt0cz60//hqWWRGrs15rc5sdEXiFMOIoJmTc+jaM58wG3c+8Rodcu biy1J9uF+muom80801+0pPwr3AOi5YfvWxKIKjz/hiq4PU3yxIluoO9jWzXpy0+IfHUjQl5AP Qv158F1bwsH9fKD8E6Ym6Zs2e0IXbR3s+ivthNGMD3FNNjGlckRlB//vGYohGHuAZ464LVKoa bUM61za1VzDhQ6aQemugX/onr+MSEpkCrUuLFvsKN1wcFR6M+uO2A7m1dAS/MUAD7lJMrJR09 CLeyp9xWn/KPy9rsvyDdMRSc7VgXVkSCjswrP0WrkbHpkI0/CnqwK+VZ9rumPAwXwxsgxmWbK 1TO+LysUEoAxZ/jofc332widMSqTxh7NCY/ItVDrWlcb9//VKRxXpH81AAr1WKjA1idKRq8Db 1Kugq6wwRm4Gwtz9gr2Xr0FcONyJ9v4xeebORyxB4R07sYn0/naIQHKqg87oA8QoiY8Jlo6Sl ywztqg/jr5XUI0KYVPBKepL4gZlvRtDPYrHjWF4Np8gMEz7BjvAGgQHF4DfKbjvGWYI2+dctD zho0omk7lqCp2F8snuFRjU9STy0SUOtytT2jR5XwQUU+rQvPG17VTbM1pBswTqAEb5YvXrLc7 k8+NJ0vp4y0oJpL1VAPLfkN84xVjYkz4t8Jq/g+I3A06Ttc/D28rheuYqhL9ff0OV26ru8zog PIysemK9TevBeoJpfv63sw8wKaL2rasx430k+ki8k= Received-SPF: pass client-ip=212.227.15.4; envelope-from=lukasstraub2@web.de; helo=mout.web.de X-Spam_score_int: -9 X-Spam_score: -1.0 X-Spam_bar: - X-Spam_report: (-1.0 / 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_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_SORBS_WEB=1.5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no 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: Kevin Wolf , "Daniel P. =?utf-8?q?Berrang=C3=A9=5C?= " , qemu-block , Juan Quintela , Markus Armbruster , "Dr. David Alan Gilbert" , Max Reitz , =?utf-8?q?Marc-Andr=C3=A9?= Lureau , Paolo Bonzini , =?utf-8?q?Marc-Andr=C3=A9?= Lureau Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hello Everyone, So here is v13. Changes: v13: -Address Marc-André Lureau comments: -make yank_register_instance return bool -rename yank_compare_instances to yank_instance_equal -remove breaks -use g_str_equal instead of strcmp -use g_new0 instead of g_slice_new -use QEMU_LOCK_GUARD instead of qemu_mutex_lock/unlock v12: -rebase onto master -minor change to migration (removal of "defer" branch in qemu_start_incoming_migration) -add Reviewed-by tags v11: -squashed MAINTAINERS update into patch 1 -move qmp doc of yank before misc -add title for qmp docs -change "Since:" to 6.0 -add Reviewed-by tags v10: -moved from qapi/misc.json to qapi/yank.json -rename 'blockdev' -> 'block-node' -document difference betwen migration yank instance and migrate_cancel -better document return values of yank command -better document yank_lock -minor style and spelling fixes v9: -rebase onto master -implemented new qmp api as proposed by Markus v8: -add Reviewed-by and Acked-by tags -rebase onto master -minor change to migration -convert to meson -change "Since:" to 5.2 -varios code style fixes (Markus Armbruster) -point to oob restrictions in comment to yank_register_function (Markus Armbruster) -improve qmp documentation (Markus Armbruster) -document oob suitability of qio_channel and io_shutdown (Markus Armbruster) v7: -yank_register_instance now returns error via Error **errp instead of aborting -dropped "chardev/char.c: Check for duplicate id before creating chardev" v6: -add Reviewed-by and Acked-by tags -rebase on master -lots of changes in nbd due to rebase -only take maintainership of util/yank.c and include/qemu/yank.h (Daniel P. Berrangé) -fix a crash discovered by the newly added chardev test -fix the test itself v5: -move yank.c to util/ -move yank.h to include/qemu/ -add license to yank.h -use const char* -nbd: use atomic_store_release and atomic_load_aqcuire -io-channel: ensure thread-safety and document it -add myself as maintainer for yank v4: -fix build errors... v3: -don't touch softmmu/vl.c, use __contructor__ attribute instead (Paolo Bonzini) -fix build errors -rewrite migration patch so it actually passes all tests v2: -don't touch io/ code anymore -always register yank functions -'yank' now takes a list of instances to yank -'query-yank' returns a list of yankable instances Overview: Hello Everyone, In many cases, if qemu has a network connection (qmp, migration, chardev, etc.) to some other server and that server dies or hangs, qemu hangs too. These patches introduce the new 'yank' out-of-band qmp command to recover from these kinds of hangs. The different subsystems register callbacks which get executed with the yank command. For example the callback can shutdown() a socket. This is intended for the colo use-case, but it can be used for other things too of course. Regards, Lukas Straub Lukas Straub (7): Introduce yank feature block/nbd.c: Add yank feature chardev/char-socket.c: Add yank feature migration: Add yank feature io/channel-tls.c: make qio_channel_tls_shutdown thread-safe io: Document qmp oob suitability of qio_channel_shutdown and io_shutdown tests/test-char.c: Wait for the chardev to connect in char_socket_client_dupid_test MAINTAINERS | 7 ++ block/nbd.c | 153 +++++++++++++++---------- chardev/char-socket.c | 34 ++++++ include/io/channel.h | 5 +- include/qemu/yank.h | 97 ++++++++++++++++ io/channel-tls.c | 6 +- migration/channel.c | 13 +++ migration/migration.c | 22 ++++ migration/multifd.c | 10 ++ migration/qemu-file-channel.c | 7 ++ migration/savevm.c | 5 + qapi/meson.build | 1 + qapi/qapi-schema.json | 1 + qapi/yank.json | 119 ++++++++++++++++++++ tests/test-char.c | 1 + util/meson.build | 1 + util/yank.c | 206 ++++++++++++++++++++++++++++++++++ 17 files changed, 624 insertions(+), 64 deletions(-) create mode 100644 include/qemu/yank.h create mode 100644 qapi/yank.json create mode 100644 util/yank.c --- 2.29.2