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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 B7D71C072B5 for ; Fri, 24 May 2019 18:38:29 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 88FE7217D7 for ; Fri, 24 May 2019 18:38:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 88FE7217D7 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 ([127.0.0.1]:58648 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hUF5I-00026i-SG for qemu-devel@archiver.kernel.org; Fri, 24 May 2019 14:38:28 -0400 Received: from eggs.gnu.org ([209.51.188.92]:37935) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hUF3f-0000rd-L2 for qemu-devel@nongnu.org; Fri, 24 May 2019 14:36:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hUF3e-0008Lm-Kx for qemu-devel@nongnu.org; Fri, 24 May 2019 14:36:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43444) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hUF3e-0008L6-B8 for qemu-devel@nongnu.org; Fri, 24 May 2019 14:36:46 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id EC6863082E0F; Fri, 24 May 2019 18:36:44 +0000 (UTC) Received: from localhost (ovpn-117-142.ams2.redhat.com [10.36.117.142]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0624D5C1B4; Fri, 24 May 2019 18:36:39 +0000 (UTC) From: Stefan Hajnoczi To: Date: Fri, 24 May 2019 19:36:35 +0100 Message-Id: <20190524183638.20745-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Fri, 24 May 2019 18:36:44 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [RFC v3 0/3] scsi: restart dma after vm change state handlers X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Fam Zheng , Kevin Wolf , Paolo Bonzini , Stefan Hajnoczi , "Michael S. Tsirkin" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" v3: * Fix s/k->vmstate_change/vdc->vmstate_change/ * Still RFC, waiting for customer to confirm this fixes the issue v2: * Do it properly with a clean API instead of deferring to a BH! Thanks for encouraging me to do this, Kevin. These patches solve a deadlock when the 'cont' command is used and there = are failed requests on a virtio-scsi device with iothreads. The deadlock its= elf is actually not the thing we need to fix because we should never reach that = case anyway. Instead we need to make sure DMA restart is only performed after= the virtio-scsi iothread is re-initialized. Stefan Hajnoczi (3): virtio: add vdc->vmchange_state() callback scsi: add scsi_bus_dma_restart() virtio-scsi: fix iothread deadlock on 'cont' include/hw/scsi/scsi.h | 5 +++++ include/hw/virtio/virtio.h | 7 +++++++ hw/scsi/scsi-bus.c | 37 ++++++++++++++++++++++++++++++------- hw/scsi/virtio-scsi.c | 17 +++++++++++++++++ hw/virtio/virtio.c | 9 +++++++++ 5 files changed, 68 insertions(+), 7 deletions(-) --=20 2.21.0