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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81F07C6FA89 for ; Thu, 15 Sep 2022 15:20:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231201AbiIOPUM (ORCPT ); Thu, 15 Sep 2022 11:20:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230253AbiIOPTz (ORCPT ); Thu, 15 Sep 2022 11:19:55 -0400 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 70F208A6C2; Thu, 15 Sep 2022 08:14:21 -0700 (PDT) Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 28FEj96e002132; Thu, 15 Sep 2022 15:14:09 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : content-transfer-encoding : mime-version; s=pp1; bh=iBlK6fyWcdkdv2FYQJ8VkvugQqpCAa9nQWW5xvOgCf8=; b=CKCoRVjroykVNMExUni7lBMrkI8p81I0BKLKf381xb4ErcQZRTd36pI5x5eYJla8HrrD 990SbvZnsEmP6aaTl/JbQGLEFD8+9EfC85HL+OxuXDOxeO/7m6oHsTluYnrXqK0Afoh7 2O53lV5FU9VM7lwaFgoH8y3vsf9RchDAQwS7t6jDSJISjGv22H8MmQJW++pSkHHosEtS DK5X4hd/diKcAsknsJKLIMdjoP0cQ7RGSry7pvO6C+4wngMm/efleUMaNHB/sXGOnxK3 SpvY4ey/CE7EKogFw2uVHQuiqaFiaImVtunwdMB33ut+yZVVoqmhR9EanteaqW64Npo8 mQ== Received: from ppma03fra.de.ibm.com (6b.4a.5195.ip4.static.sl-reverse.com [149.81.74.107]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3jm6331878-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 15 Sep 2022 15:14:08 +0000 Received: from pps.filterd (ppma03fra.de.ibm.com [127.0.0.1]) by ppma03fra.de.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 28FF84TT028185; Thu, 15 Sep 2022 15:14:06 GMT Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by ppma03fra.de.ibm.com with ESMTP id 3jjy25sydg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 15 Sep 2022 15:14:06 +0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 28FFE2SZ41157080 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 15 Sep 2022 15:14:02 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BB5BD5204F; Thu, 15 Sep 2022 15:14:02 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 48CFC52050; Thu, 15 Sep 2022 15:14:02 +0000 (GMT) From: Niklas Schnelle To: Matthew Rosato , Pierre Morel , iommu@lists.linux.dev Cc: linux-s390@vger.kernel.org, borntraeger@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, gerald.schaefer@linux.ibm.com, agordeev@linux.ibm.com, svens@linux.ibm.com, joro@8bytes.org, will@kernel.org, robin.murphy@arm.com, jgg@nvidia.com, linux-kernel@vger.kernel.org Subject: [PATCH 0/3] iommu/s390: Fixes related to repeat attach_dev calls Date: Thu, 15 Sep 2022 17:13:59 +0200 Message-Id: <20220915151402.121032-1-schnelle@linux.ibm.com> X-Mailer: git-send-email 2.34.1 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: mnO0t2SfbGSFof-WqI4BQQ9qpwbxWkIt X-Proofpoint-GUID: mnO0t2SfbGSFof-WqI4BQQ9qpwbxWkIt Content-Transfer-Encoding: 8bit X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.528,FMLib:17.11.122.1 definitions=2022-09-15_09,2022-09-14_04,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 phishscore=0 adultscore=0 malwarescore=0 bulkscore=0 mlxlogscore=579 spamscore=0 lowpriorityscore=0 priorityscore=1501 mlxscore=0 suspectscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2208220000 definitions=main-2209150085 Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org Hi All, This is a follow up to Matt's recent series[0] where he tackled a race that turned out to be outside of the s390 IOMMU driver itself as well as duplicate device attachments. After an internal discussion we came up with what I believe is a cleaner fix. Instead of actively checking for duplicates we instead detach from any previous domain on attach. From my cursory reading of the code this seems to be what the Intel IOMMU driver is doing as well. During development of this fix we realized that we can get rid of struct s390_domain_device entirely if we instead thread the list through the attached struct zpci_devs. This saves us from having to allocate during attach and gets rid of one level of indirection during IOMMU operations. Coincidentally I discovered that a previous list_head in struct zpci_dev is unused so this is removed and then replaced. The duplicate entry fix is the first patch of this series and the only one which carries a Fixes tag. It may be applied alone or together with patches 2 and 3 which are followup clean ups. Best regards, Niklas [0] https://lore.kernel.org/linux-iommu/20220831201236.77595-1-mjrosato@linux.ibm.com/ Niklas Schnelle (3): iommu/s390: Fix duplicate domain attachments s390/pci: remove unused bus_next field from struct zpci_dev iommu/s390: Get rid of s390_domain_device arch/s390/include/asm/pci.h | 2 +- drivers/iommu/s390-iommu.c | 110 +++++++++++++++++++----------------- 2 files changed, 59 insertions(+), 53 deletions(-) -- 2.34.1