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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 44DD8C433DF for ; Mon, 27 Jul 2020 06:44:08 +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 0B50B20759 for ; Mon, 27 Jul 2020 06:44:08 +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="KRMK/wqy" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0B50B20759 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]:41562 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jzwrn-0004Gz-Cj for qemu-devel@archiver.kernel.org; Mon, 27 Jul 2020 02:44:07 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52092) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jzwr6-0003pl-0O for qemu-devel@nongnu.org; Mon, 27 Jul 2020 02:43:24 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:40558 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 1jzwr3-00063u-H9 for qemu-devel@nongnu.org; Mon, 27 Jul 2020 02:43:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1595832199; 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=Vm6xXxADeqLTOLnVwumIQIXqskFrA777Gg4HEZ2Dkn0=; b=KRMK/wqyLI+NdblDHLlw2eHM9y3ExpG3BG6wEFYQeEyRTA+N1/T9sp/kiynY360+eISJjl tcG7Sc3yLyPai46Eiq9DHq69Sf/2ezutWOsi632QZzWMQEYmSjY6h/SoD0VXKN8dJ54rZu +tcEROZN63QfX/8A6sp4Qw5dY1jrumU= 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-114-Dn-yoAopNP6TkkKnbQY9QA-1; Mon, 27 Jul 2020 02:43:17 -0400 X-MC-Unique: Dn-yoAopNP6TkkKnbQY9QA-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 DFA10E919; Mon, 27 Jul 2020 06:43:16 +0000 (UTC) Received: from gondolin (ovpn-112-210.ams2.redhat.com [10.36.112.210]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9E97689507; Mon, 27 Jul 2020 06:43:12 +0000 (UTC) Date: Mon, 27 Jul 2020 08:43:10 +0200 From: Cornelia Huck To: Jason Wang Subject: Re: [BUG] vhost-vdpa: qemu-system-s390x crashes with second virtio-net-ccw device Message-ID: <20200727084310.7d29ec6d.cohuck@redhat.com> In-Reply-To: <5a0dfa0b-5a1d-e7d2-1785-8cca6ddb9db8@redhat.com> References: <20200724152718.4e1cbc9e.cohuck@redhat.com> <20200724092906-mutt-send-email-mst@kernel.org> <20200724165627.70c6dfd6.cohuck@redhat.com> <20200724111512-mutt-send-email-mst@kernel.org> <20200724173448.18773aec.cohuck@redhat.com> <5a0dfa0b-5a1d-e7d2-1785-8cca6ddb9db8@redhat.com> Organization: Red Hat GmbH MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=cohuck@redhat.com 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=cohuck@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/27 01:46:13 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -40 X-Spam_score: -4.1 X-Spam_bar: ---- X-Spam_report: (-4.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, 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=-1, 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: qemu-s390x@nongnu.org, qemu-devel@nongnu.org, Cindy Lu , "Michael S. Tsirkin" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Sat, 25 Jul 2020 08:40:07 +0800 Jason Wang wrote: > On 2020/7/24 =E4=B8=8B=E5=8D=8811:34, Cornelia Huck wrote: > > On Fri, 24 Jul 2020 11:17:57 -0400 > > "Michael S. Tsirkin" wrote: > > =20 > >> On Fri, Jul 24, 2020 at 04:56:27PM +0200, Cornelia Huck wrote: =20 > >>> On Fri, 24 Jul 2020 09:30:58 -0400 > >>> "Michael S. Tsirkin" wrote: > >>> =20 > >>>> On Fri, Jul 24, 2020 at 03:27:18PM +0200, Cornelia Huck wrote: =20 > >>>>> When I start qemu with a second virtio-net-ccw device (i.e. adding > >>>>> -device virtio-net-ccw in addition to the autogenerated device), I = get > >>>>> a segfault. gdb points to > >>>>> > >>>>> #0 0x000055d6ab52681d in virtio_net_get_config (vdev=3D, > >>>>> config=3D0x55d6ad9e3f80 "RT") at /home/cohuck/git/qemu/hw/net/= virtio-net.c:146 > >>>>> 146=09 if (nc->peer->info->type =3D=3D NET_CLIENT_DRIVER_VHOST_V= DPA) { > >>>>> > >>>>> (backtrace doesn't go further) =20 > >>> The core was incomplete, but running under gdb directly shows that it > >>> is just a bog-standard config space access (first for that device). > >>> > >>> The cause of the crash is that nc->peer is not set... no idea how tha= t > >>> can happen, not that familiar with that part of QEMU. (Should the cod= e > >>> check, or is that really something that should not happen?) > >>> > >>> What I don't understand is why it is set correctly for the first, > >>> autogenerated virtio-net-ccw device, but not for the second one, and > >>> why virtio-net-pci doesn't show these problems. The only difference > >>> between -ccw and -pci that comes to my mind here is that config space > >>> accesses for ccw are done via an asynchronous operation, so timing > >>> might be different. =20 > >> Hopefully Jason has an idea. Could you post a full command line > >> please? Do you need a working guest to trigger this? Does this trigger > >> on an x86 host? =20 > > Yes, it does trigger with tcg-on-x86 as well. I've been using > > > > s390x-softmmu/qemu-system-s390x -M s390-ccw-virtio,accel=3Dtcg -cpu qem= u,zpci=3Don > > -m 1024 -nographic -device virtio-scsi-ccw,id=3Dscsi0,devno=3Dfe.0.0001 > > -drive file=3D/path/to/image,format=3Dqcow2,if=3Dnone,id=3Ddrive-scsi0-= 0-0-0 > > -device scsi-hd,bus=3Dscsi0.0,channel=3D0,scsi-id=3D0,lun=3D0,drive=3Dd= rive-scsi0-0-0-0,id=3Dscsi0-0-0-0,bootindex=3D1 > > -device virtio-net-ccw > > > > It seems it needs the guest actually doing something with the nics; I > > cannot reproduce the crash if I use the old advent calendar moon buggy > > image and just add a virtio-net-ccw device. > > > > (I don't think it's a problem with my local build, as I see the problem > > both on my laptop and on an LPAR.) =20 >=20 >=20 > It looks to me we forget the check the existence of peer. >=20 > Please try the attached patch to see if it works. Thanks, that patch gets my guest up and running again. So, FWIW, Tested-by: Cornelia Huck Any idea why this did not hit with virtio-net-pci (or the autogenerated virtio-net-ccw device)?