From patchwork Fri Apr 9 03:44:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shenming Lu X-Patchwork-Id: 12192935 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=-13.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNWANTED_LANGUAGE_BODY, 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 41C0FC43470 for ; Fri, 9 Apr 2021 03:44:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D24561055 for ; Fri, 9 Apr 2021 03:44:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233263AbhDIDo5 (ORCPT ); Thu, 8 Apr 2021 23:44:57 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:15636 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232937AbhDIDoz (ORCPT ); Thu, 8 Apr 2021 23:44:55 -0400 Received: from DGGEMS414-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4FGkTF1XZ0znZ7R; Fri, 9 Apr 2021 11:41:53 +0800 (CST) Received: from DESKTOP-7FEPK9S.china.huawei.com (10.174.184.135) by DGGEMS414-HUB.china.huawei.com (10.3.19.214) with Microsoft SMTP Server id 14.3.498.0; Fri, 9 Apr 2021 11:44:34 +0800 From: Shenming Lu To: Alex Williamson , Cornelia Huck , Will Deacon , Robin Murphy , Joerg Roedel , Jean-Philippe Brucker , Eric Auger , , , , , CC: Kevin Tian , Lu Baolu , , Christoph Hellwig , Jonathan Cameron , Barry Song , , , Subject: [RFC PATCH v3 2/8] vfio/type1: Add a page fault handler Date: Fri, 9 Apr 2021 11:44:14 +0800 Message-ID: <20210409034420.1799-3-lushenming@huawei.com> X-Mailer: git-send-email 2.27.0.windows.1 In-Reply-To: <20210409034420.1799-1-lushenming@huawei.com> References: <20210409034420.1799-1-lushenming@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.184.135] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org VFIO manages the DMA mapping itself. To support IOPF (on-demand paging) for VFIO (IOMMU capable) devices, we add a VFIO page fault handler to serve the reported page faults from the IOMMU driver. Signed-off-by: Shenming Lu --- drivers/vfio/vfio_iommu_type1.c | 114 ++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 45cbfd4879a5..ab0ff60ee207 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -101,6 +101,7 @@ struct vfio_dma { struct task_struct *task; struct rb_root pfn_list; /* Ex-user pinned pfn list */ unsigned long *bitmap; + unsigned long *iopf_mapped_bitmap; }; struct vfio_batch { @@ -141,6 +142,16 @@ struct vfio_regions { size_t len; }; +/* A global IOPF enabled group list */ +static struct rb_root iopf_group_list = RB_ROOT; +static DEFINE_MUTEX(iopf_group_list_lock); + +struct vfio_iopf_group { + struct rb_node node; + struct iommu_group *iommu_group; + struct vfio_iommu *iommu; +}; + #define IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu) \ (!list_empty(&iommu->domain_list)) @@ -157,6 +168,10 @@ struct vfio_regions { #define DIRTY_BITMAP_PAGES_MAX ((u64)INT_MAX) #define DIRTY_BITMAP_SIZE_MAX DIRTY_BITMAP_BYTES(DIRTY_BITMAP_PAGES_MAX) +#define IOPF_MAPPED_BITMAP_GET(dma, i) \ + ((dma->iopf_mapped_bitmap[(i) / BITS_PER_LONG] \ + >> ((i) % BITS_PER_LONG)) & 0x1) + #define WAITED 1 static int put_pfn(unsigned long pfn, int prot); @@ -416,6 +431,34 @@ static int vfio_iova_put_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn) return ret; } +/* + * Helper functions for iopf_group_list + */ +static struct vfio_iopf_group * +vfio_find_iopf_group(struct iommu_group *iommu_group) +{ + struct vfio_iopf_group *iopf_group; + struct rb_node *node; + + mutex_lock(&iopf_group_list_lock); + + node = iopf_group_list.rb_node; + + while (node) { + iopf_group = rb_entry(node, struct vfio_iopf_group, node); + + if (iommu_group < iopf_group->iommu_group) + node = node->rb_left; + else if (iommu_group > iopf_group->iommu_group) + node = node->rb_right; + else + break; + } + + mutex_unlock(&iopf_group_list_lock); + return node ? iopf_group : NULL; +} + static int vfio_lock_acct(struct vfio_dma *dma, long npage, bool async) { struct mm_struct *mm; @@ -3106,6 +3149,77 @@ static int vfio_iommu_type1_dirty_pages(struct vfio_iommu *iommu, return -EINVAL; } +/* VFIO I/O Page Fault handler */ +static int vfio_iommu_type1_dma_map_iopf(struct iommu_fault *fault, void *data) +{ + struct device *dev = (struct device *)data; + struct iommu_group *iommu_group; + struct vfio_iopf_group *iopf_group; + struct vfio_iommu *iommu; + struct vfio_dma *dma; + dma_addr_t iova = ALIGN_DOWN(fault->prm.addr, PAGE_SIZE); + int access_flags = 0; + unsigned long bit_offset, vaddr, pfn; + int ret; + 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; + + iommu_group = iommu_group_get(dev); + if (!iommu_group) + return -ENODEV; + + iopf_group = vfio_find_iopf_group(iommu_group); + iommu_group_put(iommu_group); + if (!iopf_group) + return -ENODEV; + + iommu = iopf_group->iommu; + + mutex_lock(&iommu->lock); + + ret = vfio_find_dma_valid(iommu, iova, PAGE_SIZE, &dma); + if (ret < 0) + 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 (IOPF_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)) { + if (put_pfn(pfn, dma->prot)) + vfio_lock_acct(dma, -1, true); + goto out_invalid; + } + + bitmap_set(dma->iopf_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 long vfio_iommu_type1_ioctl(void *iommu_data, unsigned int cmd, unsigned long arg) {