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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 7DBB1C433DF for ; Wed, 3 Jun 2020 09:33:41 +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 4D5A22067B for ; Wed, 3 Jun 2020 09:33:41 +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="Qu8buPta" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4D5A22067B 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]:39350 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jgPmG-00026T-GX for qemu-devel@archiver.kernel.org; Wed, 03 Jun 2020 05:33:40 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48934) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jgPla-0000jp-F7 for qemu-devel@nongnu.org; Wed, 03 Jun 2020 05:32:58 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:44383 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jgPlZ-0007zd-Fc for qemu-devel@nongnu.org; Wed, 03 Jun 2020 05:32:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1591176775; 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; bh=FIulsg1S5QMQBnVWsvODhTiJ36wqdKVZ0oa+wc2og+g=; b=Qu8buPta+KI1AuIDBrH/ydqVQ5Qjf+xuJ+XdleJgWIe6pNd7MBnjuMo1SrR+a2BVbVmJ0T Sp/S5GJMEyNGhrAoyWkmTZcZ0Va4B0WlWYrtIHIAi/XRbaZE5rS2MECzB8C3U1ki7Q89w8 FPSSvXoY6KLVE5sctdw2h+iSG/gbIiY= 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-432-HmF9yeWhPCK_Y5pThZFtsQ-1; Wed, 03 Jun 2020 05:32:52 -0400 X-MC-Unique: HmF9yeWhPCK_Y5pThZFtsQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1BB23A0BE0; Wed, 3 Jun 2020 09:32:51 +0000 (UTC) Received: from dritchie.redhat.com (ovpn-112-109.rdu2.redhat.com [10.10.112.109]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7B98C45F32; Wed, 3 Jun 2020 09:32:41 +0000 (UTC) From: Sergio Lopez To: qemu-devel@nongnu.org Subject: [PATCH 0/2] virtio-blk: Avoid processing requests on the main context on restart Date: Wed, 3 Jun 2020 11:32:38 +0200 Message-Id: <20200603093240.40489-1-slp@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=205.139.110.61; envelope-from=slp@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/03 01:04:34 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] 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, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN 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 , qemu-block@nongnu.org, Sergio Lopez , "Michael S. Tsirkin" , Max Reitz , Stefan Hajnoczi Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On restart, we were scheduling a BH to process queued requests, which=0D would run before starting up the data plane, leading to those requests=0D being assigned and started on coroutines on the main context.=0D =0D This could cause requests to be wrongly processed in parallel from=0D different threads (the main thread and the iothread managing the data=0D plane), potentially leading to multiple issues.=0D =0D Fixes https://bugzilla.redhat.com/show_bug.cgi?id=3D1812765=0D =0D See "virtio-blk: Disable request queuing while switching contexts" for=0D previous discussion:=0D =0D - https://lists.gnu.org/archive/html/qemu-devel/2020-06/msg00304.html=0D =0D Sergio Lopez (2):=0D virtio-blk: Refactor the code that processes queued requests=0D virtio-blk: On restart, process queued requests in the proper context=0D =0D include/hw/virtio/virtio-blk.h | 1 +=0D hw/block/dataplane/virtio-blk.c | 8 ++++++++=0D hw/block/virtio-blk.c | 30 +++++++++++++++++++++---------=0D 3 files changed, 30 insertions(+), 9 deletions(-)=0D =0D --=20=0D 2.26.2=0D =0D