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_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 200FEC433E0 for ; Wed, 20 Jan 2021 20:51:38 +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 664CD23600 for ; Wed, 20 Jan 2021 20:51:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 664CD23600 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]:57708 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l2KS0-0002zX-EL for qemu-devel@archiver.kernel.org; Wed, 20 Jan 2021 15:51:36 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:34702) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l2KQ0-000288-6H for qemu-devel@nongnu.org; Wed, 20 Jan 2021 15:49:32 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:49722) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l2KPy-0004S8-Fj for qemu-devel@nongnu.org; Wed, 20 Jan 2021 15:49:31 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611175769; 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=23A/75KbwZnsvqTRag47B6GWCzmLaeoYFCZRLMfkt3w=; b=ccMY0JsUiKfWpx1jx2/Ap1K02yAPqGS58f9DxnyZ7PtakqiZw37Cwx5XHV3Vnzxx0qC1SV w8b0ge90Ld6jYrzaByb0SzYrZ5Vn3N6yO3swBNp31MCswqa9ONWvn2klGdsjv/C8CiWFRS 7jkMaTgF7g4tznKS2mglbjDQoS+AURI= 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-148-WbpvzPbVMw-q5r_TsagfXg-1; Wed, 20 Jan 2021 15:49:27 -0500 X-MC-Unique: WbpvzPbVMw-q5r_TsagfXg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E1149107ACE3; Wed, 20 Jan 2021 20:49:24 +0000 (UTC) Received: from [10.3.113.116] (ovpn-113-116.phx2.redhat.com [10.3.113.116]) by smtp.corp.redhat.com (Postfix) with ESMTPS id DD8DF19CB1; Wed, 20 Jan 2021 20:49:14 +0000 (UTC) To: Sergio Lopez , qemu-devel@nongnu.org References: <20201214170519.223781-1-slp@redhat.com> From: Eric Blake Organization: Red Hat, Inc. Subject: Re: [PATCH v2 0/4] nbd/server: Quiesce coroutines on context switch Message-ID: Date: Wed, 20 Jan 2021 14:49:14 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20201214170519.223781-1-slp@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 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=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit 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: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.167, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.094, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=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 , Fam Zheng , Stefano Stabellini , qemu-block@nongnu.org, Paul Durrant , "Michael S. Tsirkin" , Max Reitz , Stefan Hajnoczi , Paolo Bonzini , Anthony Perard , xen-devel@lists.xenproject.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 12/14/20 11:05 AM, Sergio Lopez wrote: > This series allows the NBD server to properly switch between AIO contexts, > having quiesced recv_coroutine and send_coroutine before doing the transition. > > We need this because we send back devices running in IO Thread owned contexts > to the main context when stopping the data plane, something that can happen > multiple times during the lifetime of a VM (usually during the boot sequence or > on a reboot), and we drag the NBD server of the correspoing export with it. > > While there, fix also a problem caused by a cross-dependency between > closing the export's client connections and draining the block > layer. The visible effect of this problem was QEMU getting hung when > the guest request a power off while there's an active NBD client. > > v2: > - Replace "virtio-blk: Acquire context while switching them on > dataplane start" with "block: Honor blk_set_aio_context() context > requirements" (Kevin Wolf) > - Add "block: Avoid processing BDS twice in > bdrv_set_aio_context_ignore()" > - Add "block: Close block exports in two steps" > - Rename nbd_read_eof() to nbd_server_read_eof() (Eric Blake) > - Fix double space and typo in comment. (Eric Blake) ping - where do we stand on this series? Patches 1 and 3 have positive reviews, I'll queue them now; patches 2 and 4 had enough comments that I'm guessing I should wait for a v3? > > Sergio Lopez (4): > block: Honor blk_set_aio_context() context requirements > block: Avoid processing BDS twice in bdrv_set_aio_context_ignore() > nbd/server: Quiesce coroutines on context switch > block: Close block exports in two steps > > block.c | 27 ++++++- > block/export/export.c | 10 +-- > blockdev-nbd.c | 2 +- > hw/block/dataplane/virtio-blk.c | 4 ++ > hw/block/dataplane/xen-block.c | 7 +- > hw/scsi/virtio-scsi.c | 6 +- > include/block/export.h | 4 +- > nbd/server.c | 120 ++++++++++++++++++++++++++++---- > qemu-nbd.c | 2 +- > stubs/blk-exp-close-all.c | 2 +- > 10 files changed, 156 insertions(+), 28 deletions(-) > -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org