From mboxrd@z Thu Jan 1 00:00:00 1970 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=-10.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 E7AEFC83014 for ; Tue, 1 Dec 2020 21:05:56 +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 111732222C for ; Tue, 1 Dec 2020 21:05:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="IY1JnWeV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 111732222C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50866 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kkCqQ-00046R-Nd for qemu-devel@archiver.kernel.org; Tue, 01 Dec 2020 16:05:54 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:42572) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kkCpp-0003Xa-K5 for qemu-devel@nongnu.org; Tue, 01 Dec 2020 16:05:17 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:49114) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kkCpm-0007Jo-B2 for qemu-devel@nongnu.org; Tue, 01 Dec 2020 16:05:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1606856713; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5UkqBHBmO3Ervf6Yb+ru5knAfdDv6uYWQZwkAkYyjgo=; b=IY1JnWeVqQKd/2JzxMEhLxg7ifoeJvCUz4BF9oz5uC7nmnSWi+mkoS7kArERzEsjj5zZ17 DQfZunUjB5YGRLHXafkhdRe0+6YGV6gHLftrS+5gqIsj8Xw8d59/ZKFVwXOcIGIM9cCsp0 gi1Lr02sgnndvm+OspVwqJK2J+WIxlw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-332-9GDdtus2P8au21QasZd3pw-1; Tue, 01 Dec 2020 16:05:09 -0500 X-MC-Unique: 9GDdtus2P8au21QasZd3pw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4C71D612A3; Tue, 1 Dec 2020 21:05:08 +0000 (UTC) Received: from [10.3.113.230] (ovpn-113-230.phx2.redhat.com [10.3.113.230]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 847E55D9CA; Tue, 1 Dec 2020 21:05:04 +0000 (UTC) Subject: Re: [PATCH v11 1/7] Introduce yank feature From: Eric Blake To: Lukas Straub , qemu-devel References: <2f88d8992faf582fc5172a8a09ec0a2df241e4f2.1605439674.git.lukasstraub2@web.de> Organization: Red Hat, Inc. Message-ID: <69324063-cc5e-590c-a905-718ca606b5cf@redhat.com> Date: Tue, 1 Dec 2020 15:05:03 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=63.128.21.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -35 X-Spam_score: -3.6 X-Spam_bar: --- X-Spam_report: (-3.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.497, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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 , =?UTF-8?Q?Daniel_P=2e_Berrang=c3=a9?= , qemu-block , Juan Quintela , "Dr. David Alan Gilbert" , Markus Armbruster , =?UTF-8?Q?Marc-Andr=c3=a9_Lureau?= , Paolo Bonzini , Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 12/1/20 2:43 PM, Eric Blake wrote: > On 11/15/20 5:36 AM, Lukas Straub wrote: >> The yank feature allows to recover from hanging qemu by "yanking" > > "allows to $verb" is not idiomatic English, better is "allows $subject > to verb" or "allows ${verb}ing". In this case, I suggest "The yank > feature allows the recovery of a hung qemu by "yanking" at various parts". > >> at various parts. Other qemu systems can register themselves and >> multiple yank functions. Then all yank functions for selected >> instances can be called by the 'yank' out-of-band qmp command. >> Available instances can be queried by a 'query-yank' oob command. >> >> Signed-off-by: Lukas Straub >> Acked-by: Stefan Hajnoczi >> Reviewed-by: Markus Armbruster >> --- > >> +# @YankInstanceType: >> +# >> +# An enumeration of yank instance types. See @YankInstance for more >> +# information. >> +# >> +# Since: 6.0 >> +## >> +{ 'enum': 'YankInstanceType', >> + 'data': [ 'block-node', 'chardev', 'migration' ] } >> + > >> +## >> +# @YankInstance: >> +# >> +# A yank instance can be yanked with the @yank qmp command to recover from a >> +# hanging QEMU. >> +# >> +# Currently implemented yank instances: >> +# - nbd block device: >> +# Yanking it will shut down the connection to the nbd server without >> +# attempting to reconnect. > > Mismatch in documentation; I presume it gets cleaned up later in the > series, in which case I can live with this patch as-is. Oh, I see. 'block-node' refers to a block node being served over NBD. So if you have multiple NBD devices, you choose which one or more nodes are yanked, rather than blindly yanking all of them at once. I just found it odd that we mention 'nbd' here but not in the enum; on the other hand, we may have more than just NBD networked devices where other types of network-enabled block nodes (ceph, sheepdog, gluster...) might also add yank support. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org