From patchwork Tue Apr 14 17:02:33 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jean-Philippe Brucker X-Patchwork-Id: 11488729 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4CD8392C for ; Tue, 14 Apr 2020 17:04:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 333B52076A for ; Tue, 14 Apr 2020 17:04:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="GCakNvEs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391162AbgDNREa (ORCPT ); Tue, 14 Apr 2020 13:04:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34540 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S2391287AbgDNRE0 (ORCPT ); Tue, 14 Apr 2020 13:04:26 -0400 Received: from mail-wm1-x341.google.com (mail-wm1-x341.google.com [IPv6:2a00:1450:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D224C061A41 for ; Tue, 14 Apr 2020 10:04:26 -0700 (PDT) Received: by mail-wm1-x341.google.com with SMTP id z6so14955330wml.2 for ; Tue, 14 Apr 2020 10:04:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=IomOGED94uQ/sc+mw27XI7cICJqvlx4xPsMfu0J0FYY=; b=GCakNvEsC05vdQy4s9DM45xHnKiEYteUAcD7FyLCP/uTecd/VeAwPmTWPNoushPNYV RNOeq6evl2T3CwdSNOB3ZpQ8cQguPZLXa9JzggKMQe0IU5xiemwq49jBFoG/HPGeV5jO t5dRmLK1E+Zg1wNi1JpDKCqwSf5Ft+LyS2I11G3Rk/AuaDJ9hliSq44RchEHC4khzI/7 FQ+xSbVGbSikxMid35s3BjzOuv/5EQZX04YWVmmNkddVLvKqNh1lYoDuSClEnEiZ8YjH NZ4PeV/mancwfAQfD0talcSAEJdsbDvnh3PrfKQsvpIiQI7cQ+G3rTKfZSYDXsO+GCmi Ua2Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=IomOGED94uQ/sc+mw27XI7cICJqvlx4xPsMfu0J0FYY=; b=uWdLGxf03OvR6nMq7izPNDNtqi/3llsM/1m4yDbE2RK9fP6yQzCUyZfq4MHz+XCNVT UQpghaLMPTDqSRQbFNeWvSX5yBDBpOZEcTHnMap65yG9BhqsY9YyQxcf3dfJVmR5X5vN AumNi/blNbZ+j0o8D6yuze98Nz54xhcEXTaC4LSzOQdkm4mMuZW3NG6xp0MbePZsT/M9 zmByUuO89Xl+ehvsZsaw+Oai4E/QDVDCyGw6ubMxRIpqtJyDeUnc0S1+mMLD7LLsxWeG 4icxYjuPm9cvmkm3o1UaLNlBnSPnjFPzqbJvKUfVDbMkEo2MLuon6Y2bl49UAEFBXunL TSCQ== X-Gm-Message-State: AGi0Pubk7dj9/S+cRQsCyOLbbqDQZs1pYTcXbwOGMvyo7Zk1fphj3HSw bLZHt3hViFjnK+JbkRKyFK+5Bw== X-Google-Smtp-Source: APiQypKbiaMvR8TIzKGaRea1UGF3OINaumxymb+GpCM64htK1x8XN0yXUI9IxJx+k4Q82m6PfxgfWw== X-Received: by 2002:a7b:cc88:: with SMTP id p8mr776491wma.108.1586883864753; Tue, 14 Apr 2020 10:04:24 -0700 (PDT) Received: from localhost.localdomain ([2001:171b:226b:54a0:116c:c27a:3e7f:5eaf]) by smtp.gmail.com with ESMTPSA id x18sm19549147wrs.11.2020.04.14.10.04.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Apr 2020 10:04:24 -0700 (PDT) From: Jean-Philippe Brucker To: iommu@lists.linux-foundation.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org, linux-mm@kvack.org Cc: joro@8bytes.org, catalin.marinas@arm.com, will@kernel.org, robin.murphy@arm.com, kevin.tian@intel.com, baolu.lu@linux.intel.com, Jonathan.Cameron@huawei.com, jacob.jun.pan@linux.intel.com, christian.koenig@amd.com, zhangfei.gao@linaro.org, jgg@ziepe.ca, xuzaibo@huawei.com, Jean-Philippe Brucker Subject: [PATCH v5 05/25] iommu/iopf: Handle mm faults Date: Tue, 14 Apr 2020 19:02:33 +0200 Message-Id: <20200414170252.714402-6-jean-philippe@linaro.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200414170252.714402-1-jean-philippe@linaro.org> References: <20200414170252.714402-1-jean-philippe@linaro.org> MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org When a recoverable page fault is handled by the fault workqueue, find the associated mm and call handle_mm_fault. Signed-off-by: Jean-Philippe Brucker --- v4->v5: no need to call mmput_async() anymore, since the MMU release() doesn't flush the IOPF queue anymore. --- drivers/iommu/io-pgfault.c | 77 +++++++++++++++++++++++++++++++++++++- 1 file changed, 75 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c index 5bba8e6a13be2..fd4244023b33f 100644 --- a/drivers/iommu/io-pgfault.c +++ b/drivers/iommu/io-pgfault.c @@ -7,6 +7,7 @@ #include #include +#include #include #include @@ -76,8 +77,57 @@ static int iopf_complete_group(struct device *dev, struct iopf_fault *iopf, static enum iommu_page_response_code iopf_handle_single(struct iopf_fault *iopf) { - /* TODO */ - return -ENODEV; + vm_fault_t ret; + struct mm_struct *mm; + struct vm_area_struct *vma; + unsigned int access_flags = 0; + unsigned int fault_flags = FAULT_FLAG_REMOTE; + struct iommu_fault_page_request *prm = &iopf->fault.prm; + enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID; + + if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID)) + return status; + + mm = iommu_sva_find(prm->pasid); + if (IS_ERR_OR_NULL(mm)) + return status; + + down_read(&mm->mmap_sem); + + vma = find_extend_vma(mm, prm->addr); + if (!vma) + /* Unmapped area */ + goto out_put_mm; + + if (prm->perm & IOMMU_FAULT_PERM_READ) + access_flags |= VM_READ; + + if (prm->perm & IOMMU_FAULT_PERM_WRITE) { + access_flags |= VM_WRITE; + fault_flags |= FAULT_FLAG_WRITE; + } + + if (prm->perm & IOMMU_FAULT_PERM_EXEC) { + access_flags |= VM_EXEC; + fault_flags |= FAULT_FLAG_INSTRUCTION; + } + + if (!(prm->perm & IOMMU_FAULT_PERM_PRIV)) + fault_flags |= FAULT_FLAG_USER; + + if (access_flags & ~vma->vm_flags) + /* Access fault */ + goto out_put_mm; + + ret = handle_mm_fault(vma, prm->addr, fault_flags); + status = ret & VM_FAULT_ERROR ? IOMMU_PAGE_RESP_INVALID : + IOMMU_PAGE_RESP_SUCCESS; + +out_put_mm: + up_read(&mm->mmap_sem); + mmput(mm); + + return status; } static void iopf_handle_group(struct work_struct *work) @@ -112,6 +162,29 @@ static void iopf_handle_group(struct work_struct *work) * * Add a fault to the device workqueue, to be handled by mm. * + * This module doesn't handle PCI PASID Stop Marker; IOMMU drivers must discard + * them before reporting faults. A PASID Stop Marker (LRW = 0b100) doesn't + * expect a response. It may be generated when disabling a PASID (issuing a + * PASID stop request) by some PCI devices. + * + * The PASID stop request is issued by the device driver before unbind(). Once + * it completes, no page request is generated for this PASID anymore and + * outstanding ones have been pushed to the IOMMU (as per PCIe 4.0r1.0 - 6.20.1 + * and 10.4.1.2 - Managing PASID TLP Prefix Usage). Some PCI devices will wait + * for all outstanding page requests to come back with a response before + * completing the PASID stop request. Others do not wait for page responses, and + * instead issue this Stop Marker that tells us when the PASID can be + * reallocated. + * + * It is safe to discard the Stop Marker because it is an optimization. + * a. Page requests, which are posted requests, have been flushed to the IOMMU + * when the stop request completes. + * b. We flush all fault queues on unbind() before freeing the PASID. + * + * So even though the Stop Marker might be issued by the device *after* the stop + * request completes, outstanding faults will have been dealt with by the time + * we free the PASID. + * * Return: 0 on success and <0 on error. */ int iommu_queue_iopf(struct iommu_fault *fault, void *cookie)