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=-7.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 E37D3C433E1 for ; Tue, 28 Jul 2020 10:53:29 +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 BA23620656 for ; Tue, 28 Jul 2020 10:53:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BA23620656 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:37668 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k0NEf-0000cm-2M for qemu-devel@archiver.kernel.org; Tue, 28 Jul 2020 06:53:29 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57458) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k0NDl-00080N-VP for qemu-devel@nongnu.org; Tue, 28 Jul 2020 06:52:33 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:3120) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k0NDj-0004p3-SV for qemu-devel@nongnu.org; Tue, 28 Jul 2020 06:52:33 -0400 Received: from pps.filterd (m0187473.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06SAc82G008841 for ; Tue, 28 Jul 2020 06:52:28 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 32jj2w8uwc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 28 Jul 2020 06:52:28 -0400 Received: from m0187473.ppops.net (m0187473.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 06SAcGOD008995 for ; Tue, 28 Jul 2020 06:52:27 -0400 Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 32jj2w8usp-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 28 Jul 2020 06:52:27 -0400 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 06SApNj9030648; Tue, 28 Jul 2020 10:52:18 GMT Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by ppma04ams.nl.ibm.com with ESMTP id 32gcy4kbq0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 28 Jul 2020 10:52:18 +0000 Received: from d06av24.portsmouth.uk.ibm.com (mk.ibm.com [9.149.105.60]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06SAqFD827787694 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 28 Jul 2020 10:52:15 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A1B0F42045; Tue, 28 Jul 2020 10:52:15 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3F43842042; Tue, 28 Jul 2020 10:52:15 +0000 (GMT) Received: from marcibm (unknown [9.145.4.48]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Tue, 28 Jul 2020 10:52:15 +0000 (GMT) From: Marc Hartmayer To: Halil Pasic , "Michael S. Tsirkin" Subject: Re: [RFC v2 2/3] libvhost-user: handle endianness as mandated by the spec In-Reply-To: <20200721184456.1305ca0b.pasic@linux.ibm.com> References: <20200717092929.19453-1-mhartmay@linux.ibm.com> <20200717092929.19453-3-mhartmay@linux.ibm.com> <20200721093942-mutt-send-email-mst@kernel.org> <20200721184456.1305ca0b.pasic@linux.ibm.com> Date: Tue, 28 Jul 2020 12:52:11 +0200 Message-ID: <87lfj39ajo.fsf@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-07-28_07:2020-07-28, 2020-07-28 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 phishscore=0 impostorscore=0 mlxlogscore=999 priorityscore=1501 lowpriorityscore=0 clxscore=1015 bulkscore=0 suspectscore=0 adultscore=0 spamscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007280081 Received-SPF: pass client-ip=148.163.156.1; envelope-from=mhartmay@linux.ibm.com; helo=mx0a-001b2d01.pphosted.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/28 04:59:18 X-ACL-Warn: Detected OS = Linux 3.1-3.10 [fuzzy] X-Spam_score_int: -35 X-Spam_score: -3.6 X-Spam_bar: --- X-Spam_report: (-3.6 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=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: =?utf-8?Q?Daniel_P=2E_Berrang?= =?utf-8?Q?=C3=A9?= , Cornelia Huck , qemu-devel@nongnu.org, "Dr. David Alan Gilbert" , Marc Hartmayer , Stefan Hajnoczi , =?utf-8?Q?M?= =?utf-8?Q?arc-Andr=C3=A9?= Lureau Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Jul 21, 2020 at 06:44 PM +0200, Halil Pasic w= rote: > On Tue, 21 Jul 2020 09:40:10 -0400 > "Michael S. Tsirkin" wrote: > >> On Fri, Jul 17, 2020 at 11:29:28AM +0200, Marc Hartmayer wrote: >> > Since virtio existed even before it got standardized, the virtio >> > standard defines the following types of virtio devices: >> >=20 >> > + legacy device (pre-virtio 1.0) >> > + non-legacy or VIRTIO 1.0 device >> > + transitional device (which can act both as legacy and non-legacy) >> >=20 >> > Virtio 1.0 defines the fields of the virtqueues as little endian, >> > while legacy uses guest's native endian [1]. Currently libvhost-user >> > does not handle virtio endianness at all, i.e. it works only if the >> > native endianness matches with whatever is actually needed. That means >> > things break spectacularly on big-endian targets. Let us handle virtio >> > endianness for non-legacy as required by the virtio specification >> > [1]. We will fence non-legacy virtio devices with the upcoming patch. >> >=20 >> > [1] https://docs.oasis-open.org/virtio/virtio/v1.1/cs01/virtio-v1.1-cs= 01.html#x1-210003 >> >=20 >> > Signed-off-by: Marc Hartmayer >> >=20 >> > --- >> > Note: As we don't support legacy virtio devices=20=20 >>=20 >> Who's "we" in this sentence? vhost user supports legacy generally ... > > In that sentence "we" is the library "libvhost-user". I would like > to avoid s390x being an oddball regarding this. Marc's previous > version made an attempt at correct endianness handling for legacy > and non-legacy. That spawned a discussion on how we don't want > legacy devices in this context. This series makes what seemed to be the > consensus reached in that discussion explicit: namely that libvhost-user > does not support legacy-virtio. Hi Michael, Polite ping - what=E2=80=99s your opinion? Thanks in advance. [=E2=80=A6snip] --=20 Kind regards / Beste Gr=C3=BC=C3=9Fe Marc Hartmayer IBM Deutschland Research & Development GmbH Vorsitzender des Aufsichtsrats: Gregor Pillen=20 Gesch=C3=A4ftsf=C3=BChrung: Dirk Wittkopp Sitz der Gesellschaft: B=C3=B6blingen Registergericht: Amtsgericht Stuttgart, HRB 243294