From patchwork Mon Nov 16 11:00:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Auger X-Patchwork-Id: 11908251 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 571ABC5519F for ; Mon, 16 Nov 2020 12:34:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E766C206D8 for ; Mon, 16 Nov 2020 12:34:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="J1ihUNn+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729515AbgKPLBZ (ORCPT ); Mon, 16 Nov 2020 06:01:25 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:56688 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728876AbgKPLBZ (ORCPT ); Mon, 16 Nov 2020 06:01:25 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605524484; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=gJAyj1O39GWEktSYG4Dy1c2uuRhlZx8GksmnaSasy+w=; b=J1ihUNn+QTTV5CY9f4HOjc/LlcsruDVhSeYJ/gYZXQeWrG6u54FrmHX3GeuMgn/o70lL5u BT3B+PI3TYmgrZazt4wyTmq84QnOmaWisS6nqYxDkqM0ckd9oZ9FXezIesTKlY5DCjw2/b lKgIrcNXixVyIpD33y0ShWJhAMqB+Ko= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-152-Ayz2YOF0M3Ki6K-PO-n9pg-1; Mon, 16 Nov 2020 06:01:22 -0500 X-MC-Unique: Ayz2YOF0M3Ki6K-PO-n9pg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1CDE46D241; Mon, 16 Nov 2020 11:01:20 +0000 (UTC) Received: from laptop.redhat.com (ovpn-113-230.ams2.redhat.com [10.36.113.230]) by smtp.corp.redhat.com (Postfix) with ESMTP id A05DC5C716; Mon, 16 Nov 2020 11:01:14 +0000 (UTC) From: Eric Auger To: eric.auger.pro@gmail.com, eric.auger@redhat.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, will@kernel.org, joro@8bytes.org, maz@kernel.org, robin.murphy@arm.com, alex.williamson@redhat.com Cc: jean-philippe@linaro.org, zhangfei.gao@linaro.org, zhangfei.gao@gmail.com, vivek.gautam@arm.com, shameerali.kolothum.thodi@huawei.com, jacob.jun.pan@linux.intel.com, yi.l.liu@intel.com, tn@semihalf.com, nicoleotsuka@gmail.com, yuzenghui@huawei.com Subject: [PATCH v11 05/13] vfio/pci: Register an iommu fault handler Date: Mon, 16 Nov 2020 12:00:22 +0100 Message-Id: <20201116110030.32335-6-eric.auger@redhat.com> In-Reply-To: <20201116110030.32335-1-eric.auger@redhat.com> References: <20201116110030.32335-1-eric.auger@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Register an IOMMU fault handler which records faults in the DMA FAULT region ring buffer. In a subsequent patch, we will add the signaling of a specific eventfd to allow the userspace to be notified whenever a new fault as shown up. Signed-off-by: Eric Auger Reported-by: kernel test robot --- v11 -> v12: - take the fault_queue_lock before reading header (Zenghui) - also record recoverable errors v10 -> v11: - move iommu_unregister_device_fault_handler into vfio_pci_disable - check fault_pages != 0 v8 -> v9: - handler now takes an iommu_fault handle - eventfd signaling moved to a subsequent patch - check the fault type and return an error if != UNRECOV - still the fault handler registration can fail. We need to reach an agreement about how to deal with the situation v3 -> v4: - move iommu_unregister_device_fault_handler to vfio_pci_release --- drivers/vfio/pci/vfio_pci.c | 45 +++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 7546a81e7fb6..b39d6ed66c71 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -27,6 +27,7 @@ #include #include #include +#include #include "vfio_pci_private.h" @@ -335,6 +336,41 @@ static const struct vfio_pci_regops vfio_pci_dma_fault_regops = { .add_capability = vfio_pci_dma_fault_add_capability, }; +int vfio_pci_iommu_dev_fault_handler(struct iommu_fault *fault, void *data) +{ + struct vfio_pci_device *vdev = (struct vfio_pci_device *)data; + struct vfio_region_dma_fault *reg = + (struct vfio_region_dma_fault *)vdev->fault_pages; + struct iommu_fault *new; + u32 head, tail, size; + int ret = -EINVAL; + + + if (WARN_ON(!reg)) + return ret; + + mutex_lock(&vdev->fault_queue_lock); + + head = reg->head; + tail = reg->tail; + size = reg->nb_entries; + + new = (struct iommu_fault *)(vdev->fault_pages + reg->offset + + head * reg->entry_size); + + if (CIRC_SPACE(head, tail, size) < 1) { + ret = -ENOSPC; + goto unlock; + } + + *new = *fault; + reg->head = (head + 1) % size; + ret = 0; +unlock: + mutex_unlock(&vdev->fault_queue_lock); + return ret; +} + #define DMA_FAULT_RING_LENGTH 512 static int vfio_pci_dma_fault_init(struct vfio_pci_device *vdev) @@ -376,6 +412,13 @@ static int vfio_pci_dma_fault_init(struct vfio_pci_device *vdev) header->entry_size = sizeof(struct iommu_fault); header->nb_entries = DMA_FAULT_RING_LENGTH; header->offset = sizeof(struct vfio_region_dma_fault); + + ret = iommu_register_device_fault_handler(&vdev->pdev->dev, + vfio_pci_iommu_dev_fault_handler, + vdev); + if (ret) /* the dma fault region is freed in vfio_pci_disable() */ + goto out; + return 0; out: kfree(vdev->fault_pages); @@ -508,6 +551,8 @@ static void vfio_pci_disable(struct vfio_pci_device *vdev) VFIO_IRQ_SET_ACTION_TRIGGER, vdev->irq_type, 0, 0, NULL); + WARN_ON(iommu_unregister_device_fault_handler(&vdev->pdev->dev)); + /* Device closed, don't need mutex here */ list_for_each_entry_safe(ioeventfd, ioeventfd_tmp, &vdev->ioeventfds_list, next) {