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 3E4CEC433F5 for ; Thu, 6 Oct 2022 14:47:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231668AbiJFOrl (ORCPT ); Thu, 6 Oct 2022 10:47:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230404AbiJFOr1 (ORCPT ); Thu, 6 Oct 2022 10:47:27 -0400 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 63B683847A; Thu, 6 Oct 2022 07:47:26 -0700 (PDT) Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 296EiDQs032370; Thu, 6 Oct 2022 14:47:08 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=05aFAD1ZDT2gSF1os1+1F9Nh7pQ0X+OlYUZkQzo7VPI=; b=FWmCrCuHv7RrzJwo7a9TGgHcgfTW7oBgFtZ03FSfLqCyoRCcUV0vWLDQw0gs/EXnJC8L xP3mT0YhEK6q9z3uGVb6xt4xPbnExB1SHAWTKMn/4rS2lEdRLkYVUy9bdJ/n/XU8KoD4 p0w15ueD2Ia31jb3nv0HR5TScyePwdUbYIZPGEy9OZIcKGoreYGp34THeC0+SEC6Vi0W LXJlzhP/GhR2lSpNpCVIryjA4GWSs3dLMVWIU1I/xMKRHpGmfbUU/q7tddJSFlLoyk66 8lENDiCfh5F0d2fQJ3Ni1hZYIdEut6rlZFUplseFgLSAyL0tNbpGLJTgkXzhVnhXH7B/ vg== Received: from ppma06ams.nl.ibm.com (66.31.33a9.ip4.static.sl-reverse.com [169.51.49.102]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3k208tsvjc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 06 Oct 2022 14:47:07 +0000 Received: from pps.filterd (ppma06ams.nl.ibm.com [127.0.0.1]) by ppma06ams.nl.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 296Ea7Hb012461; Thu, 6 Oct 2022 14:47:05 GMT Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by ppma06ams.nl.ibm.com with ESMTP id 3jxctj793x-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 06 Oct 2022 14:47:05 +0000 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 296El2N455968158 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 6 Oct 2022 14:47:02 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 12939A4051; Thu, 6 Oct 2022 14:47:02 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 984F8A4055; Thu, 6 Oct 2022 14:47:01 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 6 Oct 2022 14:47:01 +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 v5 1/6] iommu/s390: Fix duplicate domain attachments Date: Thu, 6 Oct 2022 16:46:55 +0200 Message-Id: <20221006144700.3380098-2-schnelle@linux.ibm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20221006144700.3380098-1-schnelle@linux.ibm.com> References: <20221006144700.3380098-1-schnelle@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: B8neDfbAVPahAPzQ9YoBSp0XKhMrAA8o X-Proofpoint-GUID: B8neDfbAVPahAPzQ9YoBSp0XKhMrAA8o 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=2022-10-06_02,2022-10-06_02,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 mlxlogscore=999 spamscore=0 phishscore=0 suspectscore=0 malwarescore=0 lowpriorityscore=0 impostorscore=0 clxscore=1015 bulkscore=0 priorityscore=1501 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2209130000 definitions=main-2210060085 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. While here remove the re-attach on failure dance as it was determined to be unlikely to help and may confuse debug and recovery. Fixes: fa7e9ecc5e1c ("iommu/s390: Tolerate repeat attach_dev calls") Signed-off-by: Niklas Schnelle --- v4->v5: - Unregister IOAT and set zdev->dma_table on error (Matt) drivers/iommu/s390-iommu.c | 102 ++++++++++++++++--------------------- 1 file changed, 43 insertions(+), 59 deletions(-) diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c index c898bcbbce11..938998c46bd3 100644 --- a/drivers/iommu/s390-iommu.c +++ b/drivers/iommu/s390-iommu.c @@ -79,10 +79,36 @@ static void s390_domain_free(struct iommu_domain *domain) { struct s390_domain *s390_domain = to_s390_domain(domain); + WARN_ON(!list_empty(&s390_domain->devices)); dma_cleanup_tables(s390_domain->dma_table); kfree(s390_domain); } +static void __s390_iommu_detach_device(struct zpci_dev *zdev) +{ + struct s390_domain *s390_domain = zdev->s390_domain; + struct s390_domain_device *domain_device, *tmp; + unsigned long flags; + + if (!s390_domain) + return; + + spin_lock_irqsave(&s390_domain->list_lock, flags); + list_for_each_entry_safe(domain_device, tmp, &s390_domain->devices, + list) { + if (domain_device->zdev == 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 = NULL; + zdev->dma_table = NULL; +} + static int s390_iommu_attach_device(struct iommu_domain *domain, struct device *dev) { @@ -90,7 +116,7 @@ static int s390_iommu_attach_device(struct iommu_domain *domain, struct zpci_dev *zdev = to_zpci_dev(dev); struct s390_domain_device *domain_device; unsigned long flags; - int cc, rc; + int cc, rc = 0; if (!zdev) return -ENODEV; @@ -99,23 +125,17 @@ static int s390_iommu_attach_device(struct iommu_domain *domain, if (!domain_device) return -ENOMEM; - if (zdev->dma_table && !zdev->s390_domain) { - cc = zpci_dma_exit_device(zdev); - if (cc) { - rc = -EIO; - goto out_free; - } - } - if (zdev->s390_domain) - zpci_unregister_ioat(zdev, 0); + __s390_iommu_detach_device(zdev); + else if (zdev->dma_table) + zpci_dma_exit_device(zdev); zdev->dma_table = s390_domain->dma_table; cc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma, virt_to_phys(zdev->dma_table)); if (cc) { rc = -EIO; - goto out_restore; + goto out_free; } spin_lock_irqsave(&s390_domain->list_lock, flags); @@ -127,9 +147,9 @@ static int s390_iommu_attach_device(struct iommu_domain *domain, /* Allow only devices with identical DMA range limits */ } else if (domain->geometry.aperture_start != zdev->start_dma || domain->geometry.aperture_end != zdev->end_dma) { - rc = -EINVAL; spin_unlock_irqrestore(&s390_domain->list_lock, flags); - goto out_restore; + rc = -EINVAL; + goto out_unregister; } domain_device->zdev = zdev; zdev->s390_domain = s390_domain; @@ -138,14 +158,9 @@ static int s390_iommu_attach_device(struct iommu_domain *domain, return 0; -out_restore: - if (!zdev->s390_domain) { - zpci_dma_init_device(zdev); - } else { - zdev->dma_table = zdev->s390_domain->dma_table; - zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma, - virt_to_phys(zdev->dma_table)); - } +out_unregister: + zpci_unregister_ioat(zdev, 0); + zdev->dma_table = NULL; out_free: kfree(domain_device); @@ -155,32 +170,12 @@ static int s390_iommu_attach_device(struct iommu_domain *domain, static void s390_iommu_detach_device(struct iommu_domain *domain, struct device *dev) { - struct s390_domain *s390_domain = to_s390_domain(domain); struct zpci_dev *zdev = to_zpci_dev(dev); - struct s390_domain_device *domain_device, *tmp; - unsigned long flags; - int found = 0; - if (!zdev) - return; - - spin_lock_irqsave(&s390_domain->list_lock, flags); - list_for_each_entry_safe(domain_device, tmp, &s390_domain->devices, - list) { - if (domain_device->zdev == zdev) { - list_del(&domain_device->list); - kfree(domain_device); - found = 1; - break; - } - } - spin_unlock_irqrestore(&s390_domain->list_lock, flags); + WARN_ON(zdev->s390_domain != to_s390_domain(domain)); - if (found && (zdev->s390_domain == s390_domain)) { - zdev->s390_domain = NULL; - zpci_unregister_ioat(zdev, 0); - zpci_dma_init_device(zdev); - } + __s390_iommu_detach_device(zdev); + zpci_dma_init_device(zdev); } static struct iommu_device *s390_iommu_probe_device(struct device *dev) @@ -193,24 +188,13 @@ static struct iommu_device *s390_iommu_probe_device(struct device *dev) static void s390_iommu_release_device(struct device *dev) { struct zpci_dev *zdev = to_zpci_dev(dev); - struct iommu_domain *domain; /* - * This is a workaround for a scenario where the IOMMU API common code - * "forgets" to call the detach_dev callback: After binding a device - * to vfio-pci and completing the VFIO_SET_IOMMU ioctl (which triggers - * the attach_dev), removing the device via - * "echo 1 > /sys/bus/pci/devices/.../remove" won't trigger detach_dev, - * only release_device will be called via the BUS_NOTIFY_REMOVED_DEVICE - * notifier. - * - * So let's call detach_dev from here if it hasn't been called before. + * release_device is expected to detach any domain currently attached + * to the device, but keep it attached to other devices in the group. */ - if (zdev && zdev->s390_domain) { - domain = iommu_get_domain_for_dev(dev); - if (domain) - s390_iommu_detach_device(domain, dev); - } + if (zdev) + __s390_iommu_detach_device(zdev); } static int s390_iommu_update_trans(struct s390_domain *s390_domain, -- 2.34.1