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 48DC1C433DF for ; Fri, 24 Jul 2020 15:36:04 +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 1409D206D8 for ; Fri, 24 Jul 2020 15:36:03 +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="A6x37DXV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1409D206D8 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]:60798 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jyzjv-0001vU-8O for qemu-devel@archiver.kernel.org; Fri, 24 Jul 2020 11:36:03 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39606) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jyziz-0001JW-BC for qemu-devel@nongnu.org; Fri, 24 Jul 2020 11:35:05 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:36915 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 1jyziw-0007CD-5d for qemu-devel@nongnu.org; Fri, 24 Jul 2020 11:35:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1595604900; 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=vx1v+pbyD7tmQ6EbyA9ybQXwqjjUTcwd7agbJpKTBTw=; b=A6x37DXVJMLQRMXBTvPx8YE9CjTKcdyuhWSSvGdQZwoJ2KRfbuj3Knh0p0xb58bDSZ3pbY h4VAxKHIoF3CNIjXgh2SZ/EzMa4P0Rc668CUqzRO8Kuf6ncHa3vQqLyXuJRFG5CqEd8NSd W/YLa9OJO7b+7KaK+sZy/YZjce4LQ3Q= 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-232-lj-Fsd82M6ezA5AfsmSX3A-1; Fri, 24 Jul 2020 11:34:56 -0400 X-MC-Unique: lj-Fsd82M6ezA5AfsmSX3A-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6E0C780BCAB; Fri, 24 Jul 2020 15:34:55 +0000 (UTC) Received: from gondolin (ovpn-112-188.ams2.redhat.com [10.36.112.188]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2BBDB756A0; Fri, 24 Jul 2020 15:34:51 +0000 (UTC) Date: Fri, 24 Jul 2020 17:34:48 +0200 From: Cornelia Huck To: "Michael S. Tsirkin" Subject: Re: [BUG] vhost-vdpa: qemu-system-s390x crashes with second virtio-net-ccw device Message-ID: <20200724173448.18773aec.cohuck@redhat.com> In-Reply-To: <20200724111512-mutt-send-email-mst@kernel.org> 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> Organization: Red Hat GmbH MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit 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 = 2020/07/24 06:44:00 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=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: qemu-s390x@nongnu.org, Jason Wang , qemu-devel@nongnu.org, Cindy Lu Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, 24 Jul 2020 11:17:57 -0400 "Michael S. Tsirkin" wrote: > On Fri, Jul 24, 2020 at 04:56:27PM +0200, Cornelia Huck wrote: > > On Fri, 24 Jul 2020 09:30:58 -0400 > > "Michael S. Tsirkin" wrote: > > > > > On Fri, Jul 24, 2020 at 03:27:18PM +0200, Cornelia Huck wrote: > > > > 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=, > > > > config=0x55d6ad9e3f80 "RT") at /home/cohuck/git/qemu/hw/net/virtio-net.c:146 > > > > 146 if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) { > > > > > > > > (backtrace doesn't go further) > > > > 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 that > > can happen, not that familiar with that part of QEMU. (Should the code > > 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. > > 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? Yes, it does trigger with tcg-on-x86 as well. I've been using s390x-softmmu/qemu-system-s390x -M s390-ccw-virtio,accel=tcg -cpu qemu,zpci=on -m 1024 -nographic -device virtio-scsi-ccw,id=scsi0,devno=fe.0.0001 -drive file=/path/to/image,format=qcow2,if=none,id=drive-scsi0-0-0-0 -device scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=1 -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.) > > > > > > > > > Starting qemu with no additional "-device virtio-net-ccw" (i.e., only > > > > the autogenerated virtio-net-ccw device is present) works. Specifying > > > > several "-device virtio-net-pci" works as well. > > > > > > > > Things break with 1e0a84ea49b6 ("vhost-vdpa: introduce vhost-vdpa net > > > > client"), 38140cc4d971 ("vhost_net: introduce set_config & get_config") > > > > works (in-between state does not compile). > > > > > > Ouch. I didn't test all in-between states :( > > > But I wish we had a 0-day instrastructure like kernel has, > > > that catches things like that. > > > > Yep, that would be useful... so patchew only builds the complete series? > > > > > > > > > This is reproducible with tcg as well. Same problem both with > > > > --enable-vhost-vdpa and --disable-vhost-vdpa. > > > > > > > > Have not yet tried to figure out what might be special with > > > > virtio-ccw... anyone have an idea? > > > > > > > > [This should probably be considered a blocker?] > > > > I think so, as it makes s390x unusable with more that one > > virtio-net-ccw device, and I don't even see a workaround. >