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 E854CC433F5 for ; Thu, 21 Apr 2022 05:24:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1384399AbiDUF1X (ORCPT ); Thu, 21 Apr 2022 01:27:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57160 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1384379AbiDUF1O (ORCPT ); Thu, 21 Apr 2022 01:27:14 -0400 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 224A5DFB2 for ; Wed, 20 Apr 2022 22:24:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1650518665; x=1682054665; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=HYOj1gRpbeMf/RCdKN+/GzN822Roj5neGyUWC2m/y14=; b=iINaIzRdSxejfTQ4otIXMbqRRy1fgit/ZQ4SOS+rUEXfcziQmEoFWDOF At/kRexnRHmKONEmqs5SOdI49Yr7ZzLaxqidCYRfcVDM3qjWVArh9dRqy Tbr0ptBHq8FCMYrGKLT24mUbgT17x/rMHGX1QiXjssh540JAU9hvXOzFP i6Trk9DXxBO4Zx6NQThdrTsHztmJ3yU9I902fznvewHi7l7iXRgCjqd/C 6aP9PHIzEBvq3HOO+QlZHJ7bGaQhq3HQQ9oYE342p6o/2fgjx9qIC6zPC qXPoPhmWUDzs0K55EtxnqpCbfVsi5GKsiPs0j7AvQRUhqkUFivLOQwQlj g==; X-IronPort-AV: E=McAfee;i="6400,9594,10323"; a="246135654" X-IronPort-AV: E=Sophos;i="5.90,277,1643702400"; d="scan'208";a="246135654" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Apr 2022 22:24:24 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,277,1643702400"; d="scan'208";a="702944124" Received: from allen-box.sh.intel.com ([10.239.159.48]) by fmsmga001.fm.intel.com with ESMTP; 20 Apr 2022 22:24:21 -0700 From: Lu Baolu To: Joerg Roedel , Jason Gunthorpe , Christoph Hellwig , Kevin Tian , Ashok Raj , Will Deacon , Robin Murphy , Jean-Philippe Brucker Cc: Eric Auger , Liu Yi L , Jacob jun Pan , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Lu Baolu , Jacob Pan Subject: [PATCH v4 05/12] iommu/vt-d: Remove SVM_FLAG_SUPERVISOR_MODE support Date: Thu, 21 Apr 2022 13:21:14 +0800 Message-Id: <20220421052121.3464100-6-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220421052121.3464100-1-baolu.lu@linux.intel.com> References: <20220421052121.3464100-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The current kernel DMA with PASID support is based on the SVA with a flag SVM_FLAG_SUPERVISOR_MODE. The IOMMU driver binds the kernel memory address space to a PASID of the device. The device driver programs the device with kernel virtual address (KVA) for DMA access. There have been security and functional issues with this approach: - The lack of IOTLB synchronization upon kernel page table updates. (vmalloc, module/BPF loading, CONFIG_DEBUG_PAGEALLOC etc.) - Other than slight more protection, using kernel virtual address (KVA) has little advantage over physical address. There are also no use cases yet where DMA engines need kernel virtual addresses for in-kernel DMA. This removes SVM_FLAG_SUPERVISOR_MODE support in the Intel IOMMU driver. The device driver is suggested to handle kernel DMA with PASID through the kernel DMA APIs. Link: https://lore.kernel.org/linux-iommu/20210511194726.GP1002214@nvidia.com/ Signed-off-by: Jacob Pan Signed-off-by: Lu Baolu --- drivers/iommu/intel/svm.c | 53 +++++++++------------------------------ 1 file changed, 12 insertions(+), 41 deletions(-) diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 23a38763c1d1..4c283a250541 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -313,8 +313,7 @@ static int pasid_to_svm_sdev(struct device *dev, unsigned int pasid, return 0; } -static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm, - unsigned int flags) +static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm) { ioasid_t max_pasid = dev_is_pci(dev) ? pci_max_pasids(to_pci_dev(dev)) : intel_pasid_max_id; @@ -324,8 +323,7 @@ static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm, static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu, struct device *dev, - struct mm_struct *mm, - unsigned int flags) + struct mm_struct *mm) { struct device_domain_info *info = dev_iommu_priv_get(dev); unsigned long iflags, sflags; @@ -341,22 +339,18 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu, svm->pasid = mm->pasid; svm->mm = mm; - svm->flags = flags; INIT_LIST_HEAD_RCU(&svm->devs); - if (!(flags & SVM_FLAG_SUPERVISOR_MODE)) { - svm->notifier.ops = &intel_mmuops; - ret = mmu_notifier_register(&svm->notifier, mm); - if (ret) { - kfree(svm); - return ERR_PTR(ret); - } + svm->notifier.ops = &intel_mmuops; + ret = mmu_notifier_register(&svm->notifier, mm); + if (ret) { + kfree(svm); + return ERR_PTR(ret); } ret = pasid_private_add(svm->pasid, svm); if (ret) { - if (svm->notifier.ops) - mmu_notifier_unregister(&svm->notifier, mm); + mmu_notifier_unregister(&svm->notifier, mm); kfree(svm); return ERR_PTR(ret); } @@ -391,9 +385,7 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu, } /* Setup the pasid table: */ - sflags = (flags & SVM_FLAG_SUPERVISOR_MODE) ? - PASID_FLAG_SUPERVISOR_MODE : 0; - sflags |= cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0; + sflags = cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0; spin_lock_irqsave(&iommu->lock, iflags); ret = intel_pasid_setup_first_level(iommu, dev, mm->pgd, mm->pasid, FLPT_DEFAULT_DID, sflags); @@ -410,8 +402,7 @@ static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu, kfree(sdev); free_svm: if (list_empty(&svm->devs)) { - if (svm->notifier.ops) - mmu_notifier_unregister(&svm->notifier, mm); + mmu_notifier_unregister(&svm->notifier, mm); pasid_private_remove(mm->pasid); kfree(svm); } @@ -817,37 +808,17 @@ static irqreturn_t prq_event_thread(int irq, void *d) struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct *mm, void *drvdata) { struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL); - unsigned int flags = 0; struct iommu_sva *sva; int ret; - if (drvdata) - flags = *(unsigned int *)drvdata; - - if (flags & SVM_FLAG_SUPERVISOR_MODE) { - if (!ecap_srs(iommu->ecap)) { - dev_err(dev, "%s: Supervisor PASID not supported\n", - iommu->name); - return ERR_PTR(-EOPNOTSUPP); - } - - if (mm) { - dev_err(dev, "%s: Supervisor PASID with user provided mm\n", - iommu->name); - return ERR_PTR(-EINVAL); - } - - mm = &init_mm; - } - mutex_lock(&pasid_mutex); - ret = intel_svm_alloc_pasid(dev, mm, flags); + ret = intel_svm_alloc_pasid(dev, mm); if (ret) { mutex_unlock(&pasid_mutex); return ERR_PTR(ret); } - sva = intel_svm_bind_mm(iommu, dev, mm, flags); + sva = intel_svm_bind_mm(iommu, dev, mm); mutex_unlock(&pasid_mutex); return sva; -- 2.25.1