From nobody Thu Apr 2 18:11:27 2026 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 6B247C6FA86 for ; Thu, 22 Sep 2022 09:53:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231179AbiIVJxT (ORCPT ); Thu, 22 Sep 2022 05:53:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48416 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231158AbiIVJxK (ORCPT ); Thu, 22 Sep 2022 05:53:10 -0400 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B0783D5751; Thu, 22 Sep 2022 02:53:08 -0700 (PDT) Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 28M9pFZA030921; Thu, 22 Sep 2022 09:52:47 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=V/AKv34B1wYd1USNyD5bC30pUdajk7W8PfV5PBos2Gw=; b=oOfTuR8CN5UceRA2EWa87vP1k42rIZpq9xkxjcj42g/in1XcPIq5fwkhpmluTSoj2mup wvobg4GZnClLmKa5+ceGlDAi/8cTEfKbkbIVZks00OT+rHfVQid4ekveENr9eFUgbuGu 0BrHV634xsEA9F2MwZ+QDqIPMmXnO3Te2Xh33D4VGNWEjc7EVsr7SmtN7YgHLmrIRvIT x5oR6tAanL+L68kQmr+gxvBQLm8P5Z8RDITC1yNA65d4ewM+LGITHNPqxHLeHJTuezGL m7NZEtuPcBDcF4Y3+9Pt35mdexYQFi3RjUE1DXDritMCd9qZF0XEIzrRU+2+hAlc9/he vA== Received: from ppma03ams.nl.ibm.com (62.31.33a9.ip4.static.sl-reverse.com [169.51.49.98]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3jrnek80v0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 22 Sep 2022 09:52:46 +0000 Received: from pps.filterd (ppma03ams.nl.ibm.com [127.0.0.1]) by ppma03ams.nl.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 28M9pKFi024355; Thu, 22 Sep 2022 09:52:44 GMT Received: from b06avi18878370.portsmouth.uk.ibm.com (b06avi18878370.portsmouth.uk.ibm.com [9.149.26.194]) by ppma03ams.nl.ibm.com with ESMTP id 3jn5v96eyc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 22 Sep 2022 09:52:44 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 28M9r73741746796 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 22 Sep 2022 09:53:07 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 214554C044; Thu, 22 Sep 2022 09:52:41 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A24274C046; Thu, 22 Sep 2022 09:52:40 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 22 Sep 2022 09:52:40 +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 v2 1/3] iommu/s390: Fix duplicate domain attachments Date: Thu, 22 Sep 2022 11:52:37 +0200 Message-Id: <20220922095239.2115309-2-schnelle@linux.ibm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220922095239.2115309-1-schnelle@linux.ibm.com> References: <20220922095239.2115309-1-schnelle@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: Iy3L1H_JV98y_a8kMtHrwj-ktAvEgCMF X-Proofpoint-GUID: Iy3L1H_JV98y_a8kMtHrwj-ktAvEgCMF 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=2022-09-22_06,2022-09-20_02,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 priorityscore=1501 clxscore=1015 adultscore=0 spamscore=0 phishscore=0 bulkscore=0 suspectscore=0 mlxlogscore=989 malwarescore=0 lowpriorityscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2209130000 definitions=main-2209220063 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Since commit fa7e9ecc5e1c ("iommu/s390: Tolerate repeat attach_dev calls") we can end up with duplicates in the list of devices attached to a domain. This is inefficient and confusing since only one domain can actually be in control of the IOMMU translations for a device. Fix this by detaching the device from the previous domain, if any, on attach. Add a WARN_ON() in case we still have attached devices on freeing the domain. Fixes: fa7e9ecc5e1c ("iommu/s390: Tolerate repeat attach_dev calls") Signed-off-by: Niklas Schnelle --- Changes since v1: - WARN_ON() non-empty list in s390_domain_free() - Drop the found flag and instead WARN_ON() if we're detaching from a domain that isn't the active domain for the device drivers/iommu/s390-iommu.c | 81 ++++++++++++++++++++++---------------- 1 file changed, 46 insertions(+), 35 deletions(-) diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c index c898bcbbce11..187d2c7ba9ff 100644 --- a/drivers/iommu/s390-iommu.c +++ b/drivers/iommu/s390-iommu.c @@ -78,19 +78,48 @@ static struct iommu_domain *s390_domain_alloc(unsigned = domain_type) static void s390_domain_free(struct iommu_domain *domain) { struct s390_domain *s390_domain =3D to_s390_domain(domain); + unsigned long flags; =20 + spin_lock_irqsave(&s390_domain->list_lock, flags); + WARN_ON(!list_empty(&s390_domain->devices)); + spin_unlock_irqrestore(&s390_domain->list_lock, flags); dma_cleanup_tables(s390_domain->dma_table); kfree(s390_domain); } =20 +static int __s390_iommu_detach_device(struct s390_domain *s390_domain, + struct zpci_dev *zdev) +{ + struct s390_domain_device *domain_device, *tmp; + unsigned long flags; + + WARN_ON(zdev->s390_domain !=3D s390_domain); + spin_lock_irqsave(&s390_domain->list_lock, flags); + list_for_each_entry_safe(domain_device, tmp, &s390_domain->devices, + list) { + if (domain_device->zdev =3D=3D zdev) { + list_del(&domain_device->list); + kfree(domain_device); + break; + } + } + spin_unlock_irqrestore(&s390_domain->list_lock, flags); + + zpci_unregister_ioat(zdev, 0); + zdev->s390_domain =3D NULL; + zdev->dma_table =3D NULL; + return 0; +} + static int s390_iommu_attach_device(struct iommu_domain *domain, struct device *dev) { struct s390_domain *s390_domain =3D to_s390_domain(domain); struct zpci_dev *zdev =3D to_zpci_dev(dev); struct s390_domain_device *domain_device; + struct s390_domain *prev_domain =3D NULL; unsigned long flags; - int cc, rc; + int cc, rc =3D 0; =20 if (!zdev) return -ENODEV; @@ -99,16 +128,15 @@ static int s390_iommu_attach_device(struct iommu_domai= n *domain, if (!domain_device) return -ENOMEM; =20 - if (zdev->dma_table && !zdev->s390_domain) { - cc =3D zpci_dma_exit_device(zdev); - if (cc) { + if (zdev->s390_domain) { + prev_domain =3D zdev->s390_domain; + rc =3D __s390_iommu_detach_device(zdev->s390_domain, zdev); + } else if (zdev->dma_table) { + if (zpci_dma_exit_device(zdev)) rc =3D -EIO; - goto out_free; - } } - - if (zdev->s390_domain) - zpci_unregister_ioat(zdev, 0); + if (rc) + goto out_free; =20 zdev->dma_table =3D s390_domain->dma_table; cc =3D zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma, @@ -129,7 +157,7 @@ static int s390_iommu_attach_device(struct iommu_domain= *domain, domain->geometry.aperture_end !=3D zdev->end_dma) { rc =3D -EINVAL; spin_unlock_irqrestore(&s390_domain->list_lock, flags); - goto out_restore; + goto out_unregister_restore; } domain_device->zdev =3D zdev; zdev->s390_domain =3D s390_domain; @@ -138,14 +166,15 @@ static int s390_iommu_attach_device(struct iommu_doma= in *domain, =20 return 0; =20 +out_unregister_restore: + zpci_unregister_ioat(zdev, 0); out_restore: - if (!zdev->s390_domain) { + zdev->dma_table =3D NULL; + if (prev_domain) + s390_iommu_attach_device(&prev_domain->domain, + dev); + else zpci_dma_init_device(zdev); - } else { - zdev->dma_table =3D zdev->s390_domain->dma_table; - zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma, - virt_to_phys(zdev->dma_table)); - } out_free: kfree(domain_device); =20 @@ -157,30 +186,12 @@ static void s390_iommu_detach_device(struct iommu_dom= ain *domain, { struct s390_domain *s390_domain =3D to_s390_domain(domain); struct zpci_dev *zdev =3D to_zpci_dev(dev); - struct s390_domain_device *domain_device, *tmp; - unsigned long flags; - int found =3D 0; =20 if (!zdev) return; =20 - spin_lock_irqsave(&s390_domain->list_lock, flags); - list_for_each_entry_safe(domain_device, tmp, &s390_domain->devices, - list) { - if (domain_device->zdev =3D=3D zdev) { - list_del(&domain_device->list); - kfree(domain_device); - found =3D 1; - break; - } - } - spin_unlock_irqrestore(&s390_domain->list_lock, flags); - - if (found && (zdev->s390_domain =3D=3D s390_domain)) { - zdev->s390_domain =3D NULL; - zpci_unregister_ioat(zdev, 0); + if (!__s390_iommu_detach_device(s390_domain, zdev)) zpci_dma_init_device(zdev); - } } =20 static struct iommu_device *s390_iommu_probe_device(struct device *dev) --=20 2.34.1