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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 705BFC433E0 for ; Mon, 29 Jun 2020 18:49:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5F62E204EC for ; Mon, 29 Jun 2020 18:49:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729418AbgF2St1 (ORCPT ); Mon, 29 Jun 2020 14:49:27 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:42980 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728043AbgF2StY (ORCPT ); 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Mon, 29 Jun 2020 13:16:10 +0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 05TDG7WL23724196 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 29 Jun 2020 13:16:07 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 84C4C11C069; Mon, 29 Jun 2020 13:16:07 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EEA8C11C050; Mon, 29 Jun 2020 13:15:55 +0000 (GMT) Received: from oc3016276355.ibm.com (unknown [9.145.28.234]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 29 Jun 2020 13:15:53 +0000 (GMT) Subject: Re: [PATCH v3 1/1] s390: virtio: let arch accept devices without IOMMU feature To: Halil Pasic , Cornelia Huck Cc: linux-kernel@vger.kernel.org, borntraeger@de.ibm.com, frankja@linux.ibm.com, mst@redhat.com, jasowang@redhat.com, kvm@vger.kernel.org, linux-s390@vger.kernel.org, virtualization@lists.linux-foundation.org, thomas.lendacky@amd.com, david@gibson.dropbear.id.au, linuxram@us.ibm.com, heiko.carstens@de.ibm.com, gor@linux.ibm.com References: <1592390637-17441-1-git-send-email-pmorel@linux.ibm.com> <1592390637-17441-2-git-send-email-pmorel@linux.ibm.com> <20200618002956.5f179de4.pasic@linux.ibm.com> <20200619112051.74babdb1.cohuck@redhat.com> <20200619140213.69f4992d.pasic@linux.ibm.com> From: Pierre Morel Message-ID: <833c71f2-0057-896a-5e21-2c6263834402@linux.ibm.com> Date: Mon, 29 Jun 2020 15:15:49 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200619140213.69f4992d.pasic@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216,18.0.687 definitions=2020-06-29_11:2020-06-29,2020-06-29 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 impostorscore=0 mlxscore=0 bulkscore=0 priorityscore=1501 phishscore=0 spamscore=0 clxscore=1015 malwarescore=0 mlxlogscore=937 suspectscore=0 cotscore=-2147483648 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006290089 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-06-19 14:02, Halil Pasic wrote: > On Fri, 19 Jun 2020 11:20:51 +0200 > Cornelia Huck wrote: > >>>> + if (arch_needs_virtio_iommu_platform(dev) && >>>> + !virtio_has_feature(dev, VIRTIO_F_IOMMU_PLATFORM)) { >>>> + dev_warn(&dev->dev, >>>> + "virtio: device must provide VIRTIO_F_IOMMU_PLATFORM\n"); >>> >>> I'm not sure, divulging the current Linux name of this feature bit is a >>> good idea, but if everybody else is fine with this, I don't care that >> >> Not sure if that feature name will ever change, as it is exported in >> headers. At most, we might want to add the new ACCESS_PLATFORM define >> and keep the old one, but that would still mean some churn. >> >>> much. An alternative would be: >>> "virtio: device falsely claims to have full access to the memory, >>> aborting the device" >> >> "virtio: device does not work with limited memory access" ? >> >> But no issue with keeping the current message. > > I think I prefer Conny's version, but no strong feelings here. > The reason why the device is not accepted without IOMMU_PLATFORM is arch specific, I think it should be clearly stated. If no strong oposition... Thanks, Pierre -- Pierre Morel IBM Lab Boeblingen