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 X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 BF8E9C4332E for ; Tue, 26 Jan 2021 20:46:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9BB2722228 for ; Tue, 26 Jan 2021 20:46:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730958AbhAZFEy (ORCPT ); Tue, 26 Jan 2021 00:04:54 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:11860 "EHLO szxga07-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726641AbhAYJ3Y (ORCPT ); Mon, 25 Jan 2021 04:29:24 -0500 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4DPP6m5ltjz7Zgy; Mon, 25 Jan 2021 17:03:44 +0800 (CST) Received: from DESKTOP-7FEPK9S.china.huawei.com (10.174.186.182) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.498.0; Mon, 25 Jan 2021 17:04:46 +0800 From: Shenming Lu To: Alex Williamson , Cornelia Huck , , CC: Jean-Philippe Brucker , Eric Auger , Lu Baolu , Kevin Tian , , , Subject: [RFC PATCH v1 2/4] vfio: Add a page fault handler Date: Mon, 25 Jan 2021 17:04:00 +0800 Message-ID: <20210125090402.1429-3-lushenming@huawei.com> X-Mailer: git-send-email 2.27.0.windows.1 In-Reply-To: <20210125090402.1429-1-lushenming@huawei.com> References: <20210125090402.1429-1-lushenming@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.174.186.182] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org VFIO manages the passthrough DMA mapping itself. In order to support IOPF for VFIO devices, we need to add a VFIO page fault handler to serve the reported page faults from the IOMMU driver. Signed-off-by: Shenming Lu --- drivers/vfio/vfio.c | 35 ++++++++++++++++++++ drivers/vfio/vfio_iommu_type1.c | 58 +++++++++++++++++++++++++++++++++ include/linux/vfio.h | 5 +++ 3 files changed, 98 insertions(+) diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 4ad8a35667a7..ff7797260d0f 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -2349,6 +2349,41 @@ struct iommu_domain *vfio_group_iommu_domain(struct vfio_group *group) } EXPORT_SYMBOL_GPL(vfio_group_iommu_domain); +int vfio_iommu_dev_fault_handler(struct iommu_fault *fault, void *data) +{ + struct device *dev = (struct device *)data; + struct vfio_container *container; + struct vfio_group *group; + struct vfio_iommu_driver *driver; + int ret; + + if (!dev) + return -EINVAL; + + group = vfio_group_get_from_dev(dev); + if (!group) + return -ENODEV; + + ret = vfio_group_add_container_user(group); + if (ret) + goto out; + + container = group->container; + driver = container->iommu_driver; + if (likely(driver && driver->ops->dynamic_dma_map)) + ret = driver->ops->dynamic_dma_map(container->iommu_data, + fault, dev); + else + ret = -ENOTTY; + + vfio_group_try_dissolve_container(group); + +out: + vfio_group_put(group); + return ret; +} +EXPORT_SYMBOL_GPL(vfio_iommu_dev_fault_handler); + /** * Module/class support */ diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index f1d4de5ab094..ac6f00c97897 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -145,6 +145,8 @@ struct vfio_regions { #define DIRTY_BITMAP_SIZE_MAX DIRTY_BITMAP_BYTES(DIRTY_BITMAP_PAGES_MAX) #define IOMMU_MAPPED_BITMAP_BYTES(n) DIRTY_BITMAP_BYTES(n) +#define IOMMU_MAPPED_BITMAP_GET(dma, i) ((dma->iommu_mapped_bitmap[i / BITS_PER_LONG] \ + >> (i % BITS_PER_LONG)) & 0x1) static int put_pfn(unsigned long pfn, int prot); @@ -2992,6 +2994,61 @@ static int vfio_iommu_type1_dma_rw(void *iommu_data, dma_addr_t user_iova, return ret; } +static int vfio_iommu_type1_dynamic_dma_map(void *iommu_data, + struct iommu_fault *fault, + struct device *dev) +{ + struct vfio_iommu *iommu = iommu_data; + dma_addr_t iova = ALIGN_DOWN(fault->prm.addr, PAGE_SIZE); + struct vfio_dma *dma; + int access_flags = 0; + unsigned long bit_offset, vaddr, pfn; + enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID; + struct iommu_page_response resp = {0}; + + if (fault->type != IOMMU_FAULT_PAGE_REQ) + return -EOPNOTSUPP; + + mutex_lock(&iommu->lock); + + dma = vfio_find_dma(iommu, iova, PAGE_SIZE); + if (!dma) + goto out_invalid; + + if (fault->prm.perm & IOMMU_FAULT_PERM_READ) + access_flags |= IOMMU_READ; + if (fault->prm.perm & IOMMU_FAULT_PERM_WRITE) + access_flags |= IOMMU_WRITE; + if ((dma->prot & access_flags) != access_flags) + goto out_invalid; + + bit_offset = (iova - dma->iova) >> PAGE_SHIFT; + if (IOMMU_MAPPED_BITMAP_GET(dma, bit_offset)) + goto out_success; + + vaddr = iova - dma->iova + dma->vaddr; + if (vfio_pin_page_external(dma, vaddr, &pfn, true)) + goto out_invalid; + + if (vfio_iommu_map(iommu, iova, pfn, 1, dma->prot)) { + vfio_unpin_page_external(dma, iova, true); + goto out_invalid; + } + + bitmap_set(dma->iommu_mapped_bitmap, bit_offset, 1); + +out_success: + status = IOMMU_PAGE_RESP_SUCCESS; + +out_invalid: + mutex_unlock(&iommu->lock); + resp.version = IOMMU_PAGE_RESP_VERSION_1; + resp.grpid = fault->prm.grpid; + resp.code = status; + iommu_page_response(dev, &resp); + return 0; +} + static struct iommu_domain * vfio_iommu_type1_group_iommu_domain(void *iommu_data, struct iommu_group *iommu_group) @@ -3028,6 +3085,7 @@ static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = { .register_notifier = vfio_iommu_type1_register_notifier, .unregister_notifier = vfio_iommu_type1_unregister_notifier, .dma_rw = vfio_iommu_type1_dma_rw, + .dynamic_dma_map = vfio_iommu_type1_dynamic_dma_map, .group_iommu_domain = vfio_iommu_type1_group_iommu_domain, }; diff --git a/include/linux/vfio.h b/include/linux/vfio.h index f45940b38a02..6d535f029f21 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -90,6 +90,9 @@ struct vfio_iommu_driver_ops { struct notifier_block *nb); int (*dma_rw)(void *iommu_data, dma_addr_t user_iova, void *data, size_t count, bool write); + int (*dynamic_dma_map)(void *iommu_data, + struct iommu_fault *fault, + struct device *dev); struct iommu_domain *(*group_iommu_domain)(void *iommu_data, struct iommu_group *group); }; @@ -153,6 +156,8 @@ extern int vfio_unregister_notifier(struct device *dev, struct kvm; extern void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm); +extern int vfio_iommu_dev_fault_handler(struct iommu_fault *fault, void *data); + /* * Sub-module helpers */ -- 2.19.1