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_PASS,URIBL_BLOCKED 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 45F1DC7112F for ; Mon, 21 Jan 2019 11:51:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1C3552085A for ; Mon, 21 Jan 2019 11:51:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728247AbfAULvX (ORCPT ); Mon, 21 Jan 2019 06:51:23 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:48968 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727544AbfAULvW (ORCPT ); Mon, 21 Jan 2019 06:51:22 -0500 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x0LBnUd6139957 for ; Mon, 21 Jan 2019 06:51:21 -0500 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0b-001b2d01.pphosted.com with ESMTP id 2q5chmayat-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 21 Jan 2019 06:51:21 -0500 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 21 Jan 2019 11:51:16 -0000 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x0LBpFPh20971522 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 21 Jan 2019 11:51:15 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0008942045; Mon, 21 Jan 2019 11:51:14 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9754D42047; Mon, 21 Jan 2019 11:51:14 +0000 (GMT) Received: from [9.152.224.140] (unknown [9.152.224.140]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 21 Jan 2019 11:51:14 +0000 (GMT) Reply-To: pmorel@linux.ibm.com Subject: Re: [PATCH v1] iommu/s390: Declare s390 iommu reserved regions To: Jean-Philippe Brucker , Robin Murphy , gerald.schaefer@de.ibm.com Cc: linux-s390@vger.kernel.org, walling@linux.ibm.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, alex.williamson@redhat.com References: <1547573850-9459-1-git-send-email-pmorel@linux.ibm.com> <3cd790d6-aa6f-e817-27ce-56d7a9b6b6e5@linux.ibm.com> <668fe734-e4bf-0342-ab8c-df54d9022db4@arm.com> From: Pierre Morel Date: Mon, 21 Jan 2019 12:51:14 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <668fe734-e4bf-0342-ab8c-df54d9022db4@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19012111-0020-0000-0000-000003094932 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19012111-0021-0000-0000-0000215A77EF Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-01-21_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1901210094 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 18/01/2019 14:51, Jean-Philippe Brucker wrote: > Hi Pierre, > > On 18/01/2019 13:29, Pierre Morel wrote: >> On 17/01/2019 14:02, Robin Murphy wrote: >>> On 15/01/2019 17:37, Pierre Morel wrote: >>>> The s390 iommu can only allow DMA transactions between the zPCI device >>>> entries start_dma and end_dma. >>>> ... >> >> I already posted a patch retrieving the geometry through >> VFIO_IOMMU_GET_INFO using a specific capability for the geometry [1], >> and AFAIU, Alex did not agree with this. > > On arm we also need to report the IOMMU geometry to userspace (max IOVA > size in particular). Shameer has been working on a solution [2] that > presents a unified view of both geometry and reserved regions into the > VFIO_IOMMU_GET_INFO call, and I think we should go with that. If I > understand correctly it's currently blocked on the RMRR problem and > we're waiting for Jacob or Ashok to take a look at it, as Kevin pinged > them on thread [1]? > > [2] https://lkml.org/lkml/2018/4/18/293 > > Thanks, > Jean > Hi Jean, I hopped that this proposition went in the same direction based on the following assumptions: - The goal of the get_resv_region is defined in iommu.h as: ----- * @get_resv_regions: Request list of reserved regions for a device ----- - A iommu reserve region is a region which should not be mapped. Isn't it exactly what happens outside the aperture? Shouldn't it be reported by the iommu reserved region? - If we use VFIO and want to get all reserved region we will have the VFIO_IOMMU_GET_INFO call provided by Shameer and it can get all reserved regions depending from the iommu driver itself at once by calling the get_reserved_region callback instead of having to merge them with the aperture. - If there are other reserved region, depending on the system configuration and not on the IOMMU itself, the VFIO_IOMMU_GET_INFO call will have to merge them with the region gotten from the iommu driver. - If we do not use QEMU nor VFIO at all, AFAIU, the standard way to retrieve the reserved regions associated with a device is to call the get_reserved_region callback from the associated iommu. Please tell me were I am wrong. Regards, Pierre >> >> What is different in what you propose? >> >> @Alex: I was hoping that this patch goes in your direction. What do you >> think? >> >> Thanks, >> Pierre >> >> [1]: https://lore.kernel.org/patchwork/patch/1030369/ >> >>> >>>> >>>> This seems to me related with the work Shameer has started on >>>> vfio_iommu_type1 so I add Alex and Shameer to the CC list. >>>> >>>> >>>> Pierre Morel (1): >>>>    iommu/s390: Declare s390 iommu reserved regions >>>> >>>>   drivers/iommu/s390-iommu.c | 29 +++++++++++++++++++++++++++++ >>>>   1 file changed, 29 insertions(+) >>>> >>> >> >> > -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany