From patchwork Fri Oct 30 16:40:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Lukas Straub X-Patchwork-Id: 1391153 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; dmarc=fail (p=none dis=none) header.from=web.de Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; secure) header.d=web.de header.i=@web.de header.a=rsa-sha256 header.s=dbaedf251592 header.b=GzhocY6J; 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 4CN7Pt3DKvz9s0b for ; Sat, 31 Oct 2020 03:42:10 +1100 (AEDT) Received: from localhost ([::1]:59808 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kYXTc-0004Mw-8L for incoming@patchwork.ozlabs.org; Fri, 30 Oct 2020 12:42:08 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55744) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kYXSj-0004LS-OR; Fri, 30 Oct 2020 12:41:13 -0400 Received: from mout.web.de ([217.72.192.78]:58891) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kYXSh-0002yb-Cr; Fri, 30 Oct 2020 12:41:13 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=web.de; s=dbaedf251592; t=1604076064; bh=cEnGF3z6JFjp1yKe9fS8Lol1ng9vUZxbZH5HFD9YxDA=; h=X-UI-Sender-Class:Date:From:To:Cc:Subject; b=GzhocY6JF+zto9WG1czesanHdb51mogKmFHCia9Vl4a3KkuAFolJfo3WXCgIeUcrv 86qzdviwtyPjJF+APwD8KXwV2NyEyX3qv+BvwOY7jjKgykbXVfDjATi+5W2IqRjDnb JwfaARMG0qBTLBTtg6kiJ1bL2hkw3UCg740WiQr8= X-UI-Sender-Class: c548c8c5-30a9-4db5-a2e7-cb6cb037b8f9 Received: from luklap ([87.123.206.100]) by smtp.web.de (mrweb105 [213.165.67.124]) with ESMTPSA (Nemesis) id 1N3ouw-1kPqKW2WA4-00zpVR; Fri, 30 Oct 2020 17:41:04 +0100 Date: Fri, 30 Oct 2020 17:40:43 +0100 From: Lukas Straub To: qemu-devel Subject: [PATCH v10 0/8] Introduce 'yank' oob qmp command to recover from hanging qemu Message-ID: <20201030174043.35300683@luklap> MIME-Version: 1.0 X-Provags-ID: V03:K1:KTfO22uQAZN7z/LBxV4S0befgY5ocDWtUyTNm7kslt5mxh149UN NQxCjKXpRhBA6cqxEKHbdCBM+13MwVuJtjy4xA6ruA/OizjFHUfwvGP+Wo4Re7l60WPsGF3 4c97z1WF+uyqsZaUGIa8yFPlU6HeQosFcHx02JYQdRel+TOWwcIsS8P/xNPZqDP7BzR7At6 mhhkslwl5GYTNbNFqoPuA== X-UI-Out-Filterresults: notjunk:1;V03:K0:4ji+KlfLjdk=:z13t2zrx3JWhdHwqNxSRH0 otXGgP4reyTtgUxDUu0kgkR9bGHhn406xp1vo8OBu9Cgz5YkZdlbWWvWJe89Ng3PoPGQ7Ro47 HKwAmdcEH1fhKR3hhG7UxvIF7fjhmzjb57TwF/0fHqoa/3rGp8CoWQSuZjg72aj0ynl3sVu8G 97RKnUdvf1iXHK3sKCs9FBrm6HSdXfSQVGah4s9fVhHvo6yVFOQw0VvOlhPhA60xP+CvLZO7W RcUxnAIQMvcmIAYsHBle4QOEbOKgKX6Ghagh1EwOmFVMvnxf0rTV2qj/Ux8BE2rbklZXMmJ28 CIgOwKfueHYRlGKmM6lvBTublV8Pw1c3x+dN/oab4Ci48PVuK0NbZ34Apxu9CktD2DLwOdanu VmVHZY8NiVgXrkUE7Cii60tdqJYIfRBPTW588Dvqo4hLOtUqb6HZa5aTNgSiq7on4fuM25XmP f1oeobgSXeU0FVol8H9YDprsNRHRZ1S5eTqDojJJt+/mVqqL0hXGwAjkjzh8WowzzGXwdxiY0 DdOumA43rsFFeqss57BbyTMc9w5pGA+K2zR2St/2pQxgaMaObQ+Rv7GIJMzQ2Cfo1iVNtRsdv RYWqPOJtnjPQ3qzq63w+8zrg7k2NnSTEMVKV9Hr0z2d0ZvcRWSJDfcNrB4TaO8UblihJUGOiu E68X7r+7w+N4DzJT4rWBTWhCgGqne+x6NA4owandhjZ+8DxAVBfIK6eZioQgwHQpK02WBkct4 lvx5NRxweBtAZXu/pcqoQxgMDMGQC8Cz/TBcEfd2SavhIj8UnijKnZb1AZfsw+gzVZNIt4nkD 917HgZ4RXKBAkfnyGHnCr7NOKY+x7qpEBpM8GGpZKn/fv0uKtgaOVEI7NcTNTlSUHYNv69gmD Qd6ov40G4GEzN029sF6A== Received-SPF: pass client-ip=217.72.192.78; envelope-from=lukasstraub2@web.de; helo=mout.web.de X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/30 12:41:09 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -24 X-Spam_score: -2.5 X-Spam_bar: -- X-Spam_report: (-2.5 / 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_H2=-0.001, 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: Kevin Wolf , "Daniel P. =?utf-8?b?QmVycmFuZ8Op?= " , qemu-block , Juan Quintela , Markus Armbruster , "Dr. David Alan Gilbert" , Max Reitz , Paolo Bonzini , =?utf-8?q?Marc-Andr=C3=A9?= Lureau Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Hello Everyone, So here is v10. We still need ACKs from NBD and chardev maintainers. Changes: 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 -beter 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 (8): 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 MAINTAINERS: Add myself as maintainer for yank feature tests/test-char.c: Wait for the chardev to connect in char_socket_client_dupid_test MAINTAINERS | 7 ++ block/nbd.c | 154 ++++++++++++++---------- chardev/char-socket.c | 35 ++++++ include/io/channel.h | 5 +- include/qemu/yank.h | 95 +++++++++++++++ io/channel-tls.c | 6 +- migration/channel.c | 13 ++ migration/migration.c | 25 ++++ migration/multifd.c | 10 ++ migration/qemu-file-channel.c | 7 ++ migration/savevm.c | 6 + qapi/meson.build | 1 + qapi/qapi-schema.json | 1 + qapi/yank.json | 115 ++++++++++++++++++ tests/test-char.c | 1 + util/meson.build | 1 + util/yank.c | 216 ++++++++++++++++++++++++++++++++++ 17 files changed, 634 insertions(+), 64 deletions(-) create mode 100644 include/qemu/yank.h create mode 100644 qapi/yank.json create mode 100644 util/yank.c --- 2.20.1