From patchwork Wed Mar 31 08:05:17 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yongji Xie X-Patchwork-Id: 12174659 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,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 C0363C433E0 for ; Wed, 31 Mar 2021 08:07:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8958A619CF for ; Wed, 31 Mar 2021 08:07:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234263AbhCaIHX (ORCPT ); Wed, 31 Mar 2021 04:07:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234264AbhCaIGs (ORCPT ); Wed, 31 Mar 2021 04:06:48 -0400 Received: from mail-pj1-x1031.google.com (mail-pj1-x1031.google.com [IPv6:2607:f8b0:4864:20::1031]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D86E2C061761 for ; Wed, 31 Mar 2021 01:06:47 -0700 (PDT) Received: by mail-pj1-x1031.google.com with SMTP id t18so9096857pjs.3 for ; Wed, 31 Mar 2021 01:06:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=HbraA3GUovC8HHTDRA7rAWyMS2fMttNNZ7zYmSxaNBY=; b=ZdQWmMXK9LqN6EYFwFf0L9s6oXuyIZpAdQsFntchgz8PAhwq39LE/ebytNk3l8q2mA bxcztYw/rnEjlk2Pky3tfNiH9RgpaLI20J6AhLQjaRJdvHKXqh5J5rTPzsZw0ZDLpScq NwfATuKhV78C4KMIDBlhuEtyTQW4C44WD2yqWDx04FV3vGOrLylK5KUeO8NwkTpO7LFr 8OZ2xsBxtNwsC9rCT4/7peYjPH8VieOCzVggkbwBtEj5Xmh4aPOOITaJ67tLOtRMD5f2 rBEQrAsS2tfpQ5rjSikk33pwBulf1LsHjAmexwDOHMhqXcC7UgjSZTuqE83HjYPPowZu unVA== 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=HbraA3GUovC8HHTDRA7rAWyMS2fMttNNZ7zYmSxaNBY=; b=mgkMe5tvRy+Z9tJd8F3Uvums0RHfvdYdRD7e5HOAwDro7NTpHetMNoflVrRVm17MNO /h+5FQRh1SjjhLU5Y1eJJgteUEeJniVvxperLz/Vcwo/9WLqeJXcXfVfenP2Pr/Sj9+Q j245NIn7HnhIvxKa2K88aZCg/zZeiXi5AOCCutpp/rDs5RKxSNf1/1zZCOuGjXglmKZz Z2uDmaCyA/qNkuwruB0ZEMQrUOLBnxE78t3/VGkn21l4RDhfSYYd6NZDA9jzTuLniWji 6ke8LBjtey9+xgx3MO7dGbywdh82paFGRzQgGlRKe+7QnoanTZ/UNCV+loZX/wM6Zkg5 TGLQ== X-Gm-Message-State: AOAM5301E6hKe7LStodXSBhcCytjPSUudkljcxwUDodfB0vwjj7oCcfT 0R9tZdyVpmElcKAnRBXhrOE7 X-Google-Smtp-Source: ABdhPJzt0qlYOwcRoCM3jkPHzS0Gq67t3fffprT5Aqw3JmwBJUh2R1np6vAzPu9Ndl0yrj208n0KCg== X-Received: by 2002:a17:902:e806:b029:e5:cb85:dc4d with SMTP id u6-20020a170902e806b02900e5cb85dc4dmr2140059plg.11.1617178007339; Wed, 31 Mar 2021 01:06:47 -0700 (PDT) Received: from localhost ([139.177.225.243]) by smtp.gmail.com with ESMTPSA id a5sm1366317pfo.210.2021.03.31.01.06.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 31 Mar 2021 01:06:46 -0700 (PDT) From: Xie Yongji To: mst@redhat.com, jasowang@redhat.com, stefanha@redhat.com, sgarzare@redhat.com, parav@nvidia.com, hch@infradead.org, christian.brauner@canonical.com, rdunlap@infradead.org, willy@infradead.org, viro@zeniv.linux.org.uk, axboe@kernel.dk, bcrl@kvack.org, corbet@lwn.net, mika.penttila@nextfour.com, dan.carpenter@oracle.com Cc: virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, kvm@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v6 08/10] vduse: Implement an MMU-based IOMMU driver Date: Wed, 31 Mar 2021 16:05:17 +0800 Message-Id: <20210331080519.172-9-xieyongji@bytedance.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210331080519.172-1-xieyongji@bytedance.com> References: <20210331080519.172-1-xieyongji@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This implements an MMU-based IOMMU driver to support mapping kernel dma buffer into userspace. The basic idea behind it is treating MMU (VA->PA) as IOMMU (IOVA->PA). The driver will set up MMU mapping instead of IOMMU mapping for the DMA transfer so that the userspace process is able to use its virtual address to access the dma buffer in kernel. And to avoid security issue, a bounce-buffering mechanism is introduced to prevent userspace accessing the original buffer directly. Signed-off-by: Xie Yongji Acked-by: Jason Wang --- drivers/vdpa/vdpa_user/iova_domain.c | 521 +++++++++++++++++++++++++++++++++++ drivers/vdpa/vdpa_user/iova_domain.h | 70 +++++ 2 files changed, 591 insertions(+) create mode 100644 drivers/vdpa/vdpa_user/iova_domain.c create mode 100644 drivers/vdpa/vdpa_user/iova_domain.h diff --git a/drivers/vdpa/vdpa_user/iova_domain.c b/drivers/vdpa/vdpa_user/iova_domain.c new file mode 100644 index 000000000000..ed2a944d99b4 --- /dev/null +++ b/drivers/vdpa/vdpa_user/iova_domain.c @@ -0,0 +1,521 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * MMU-based IOMMU implementation + * + * Copyright (C) 2020-2021 Bytedance Inc. and/or its affiliates. All rights reserved. + * + * Author: Xie Yongji + * + */ + +#include +#include +#include +#include +#include +#include + +#include "iova_domain.h" + +static int vduse_iotlb_add_range(struct vduse_iova_domain *domain, + u64 start, u64 last, + u64 addr, unsigned int perm, + struct file *file, u64 offset) +{ + struct vdpa_map_file *map_file; + int ret; + + map_file = kmalloc(sizeof(*map_file), GFP_ATOMIC); + if (!map_file) + return -ENOMEM; + + map_file->file = get_file(file); + map_file->offset = offset; + + ret = vhost_iotlb_add_range_ctx(domain->iotlb, start, last, + addr, perm, map_file); + if (ret) { + fput(map_file->file); + kfree(map_file); + return ret; + } + return 0; +} + +static void vduse_iotlb_del_range(struct vduse_iova_domain *domain, + u64 start, u64 last) +{ + struct vdpa_map_file *map_file; + struct vhost_iotlb_map *map; + + while ((map = vhost_iotlb_itree_first(domain->iotlb, start, last))) { + map_file = (struct vdpa_map_file *)map->opaque; + fput(map_file->file); + kfree(map_file); + vhost_iotlb_map_free(domain->iotlb, map); + } +} + +int vduse_domain_set_map(struct vduse_iova_domain *domain, + struct vhost_iotlb *iotlb) +{ + struct vdpa_map_file *map_file; + struct vhost_iotlb_map *map; + u64 start = 0ULL, last = ULLONG_MAX; + int ret; + + spin_lock(&domain->iotlb_lock); + vduse_iotlb_del_range(domain, start, last); + + for (map = vhost_iotlb_itree_first(iotlb, start, last); map; + map = vhost_iotlb_itree_next(map, start, last)) { + map_file = (struct vdpa_map_file *)map->opaque; + ret = vduse_iotlb_add_range(domain, map->start, map->last, + map->addr, map->perm, + map_file->file, + map_file->offset); + if (ret) + goto err; + } + spin_unlock(&domain->iotlb_lock); + + return 0; +err: + vduse_iotlb_del_range(domain, start, last); + spin_unlock(&domain->iotlb_lock); + return ret; +} + +static int vduse_domain_map_bounce_page(struct vduse_iova_domain *domain, + u64 iova, u64 size, u64 paddr) +{ + struct vduse_bounce_map *map; + u64 last = iova + size - 1; + + while (iova <= last) { + map = &domain->bounce_maps[iova >> PAGE_SHIFT]; + if (!map->bounce_page) { + map->bounce_page = alloc_page(GFP_ATOMIC); + if (!map->bounce_page) + return -ENOMEM; + } + map->orig_phys = paddr; + paddr += PAGE_SIZE; + iova += PAGE_SIZE; + } + return 0; +} + +static void vduse_domain_unmap_bounce_page(struct vduse_iova_domain *domain, + u64 iova, u64 size) +{ + struct vduse_bounce_map *map; + u64 last = iova + size - 1; + + while (iova <= last) { + map = &domain->bounce_maps[iova >> PAGE_SHIFT]; + map->orig_phys = INVALID_PHYS_ADDR; + iova += PAGE_SIZE; + } +} + +static void do_bounce(phys_addr_t orig, void *addr, size_t size, + enum dma_data_direction dir) +{ + unsigned long pfn = PFN_DOWN(orig); + unsigned int offset = offset_in_page(orig); + char *buffer; + unsigned int sz = 0; + + while (size) { + sz = min_t(size_t, PAGE_SIZE - offset, size); + + buffer = kmap_atomic(pfn_to_page(pfn)); + if (dir == DMA_TO_DEVICE) + memcpy(addr, buffer + offset, sz); + else + memcpy(buffer + offset, addr, sz); + kunmap_atomic(buffer); + + size -= sz; + pfn++; + addr += sz; + offset = 0; + } +} + +static void vduse_domain_bounce(struct vduse_iova_domain *domain, + dma_addr_t iova, size_t size, + enum dma_data_direction dir) +{ + struct vduse_bounce_map *map; + unsigned int offset; + void *addr; + size_t sz; + + while (size) { + map = &domain->bounce_maps[iova >> PAGE_SHIFT]; + offset = offset_in_page(iova); + sz = min_t(size_t, PAGE_SIZE - offset, size); + + if (WARN_ON(!map->bounce_page || + map->orig_phys == INVALID_PHYS_ADDR)) + return; + + addr = page_address(map->bounce_page) + offset; + do_bounce(map->orig_phys + offset, addr, sz, dir); + size -= sz; + iova += sz; + } +} + +static struct page * +vduse_domain_get_mapping_page(struct vduse_iova_domain *domain, u64 iova) +{ + u64 start = iova & PAGE_MASK; + u64 last = start + PAGE_SIZE - 1; + struct vhost_iotlb_map *map; + struct page *page = NULL; + + spin_lock(&domain->iotlb_lock); + map = vhost_iotlb_itree_first(domain->iotlb, start, last); + if (!map) + goto out; + + page = pfn_to_page((map->addr + iova - map->start) >> PAGE_SHIFT); + get_page(page); +out: + spin_unlock(&domain->iotlb_lock); + + return page; +} + +static struct page * +vduse_domain_get_bounce_page(struct vduse_iova_domain *domain, u64 iova) +{ + struct vduse_bounce_map *map; + struct page *page = NULL; + + spin_lock(&domain->iotlb_lock); + map = &domain->bounce_maps[iova >> PAGE_SHIFT]; + if (!map->bounce_page) + goto out; + + page = map->bounce_page; + get_page(page); +out: + spin_unlock(&domain->iotlb_lock); + + return page; +} + +static void +vduse_domain_free_bounce_pages(struct vduse_iova_domain *domain) +{ + struct vduse_bounce_map *map; + unsigned long pfn, bounce_pfns; + + spin_lock(&domain->iotlb_lock); + bounce_pfns = domain->bounce_size >> PAGE_SHIFT; + + for (pfn = 0; pfn < bounce_pfns; pfn++) { + map = &domain->bounce_maps[pfn]; + if (WARN_ON(map->orig_phys != INVALID_PHYS_ADDR)) + continue; + + if (!map->bounce_page) + continue; + + __free_page(map->bounce_page); + map->bounce_page = NULL; + } + spin_unlock(&domain->iotlb_lock); +} + +void vduse_domain_reset_bounce_map(struct vduse_iova_domain *domain) +{ + if (!domain->bounce_map) + return; + + spin_lock(&domain->iotlb_lock); + if (!domain->bounce_map) + goto unlock; + + vduse_iotlb_del_range(domain, 0, domain->bounce_size - 1); + domain->bounce_map = 0; +unlock: + spin_unlock(&domain->iotlb_lock); +} + +static int vduse_domain_init_bounce_map(struct vduse_iova_domain *domain) +{ + int ret = 0; + + if (domain->bounce_map) + return 0; + + spin_lock(&domain->iotlb_lock); + if (domain->bounce_map) + goto unlock; + + ret = vduse_iotlb_add_range(domain, 0, domain->bounce_size - 1, + 0, VHOST_MAP_RW, domain->file, 0); + if (ret) + goto unlock; + + domain->bounce_map = 1; +unlock: + spin_unlock(&domain->iotlb_lock); + return ret; +} + +static dma_addr_t +vduse_domain_alloc_iova(struct iova_domain *iovad, + unsigned long size, unsigned long limit) +{ + unsigned long shift = iova_shift(iovad); + unsigned long iova_len = iova_align(iovad, size) >> shift; + unsigned long iova_pfn; + + if (iova_len < (1 << (IOVA_RANGE_CACHE_MAX_SIZE - 1))) + iova_len = roundup_pow_of_two(iova_len); + iova_pfn = alloc_iova_fast(iovad, iova_len, limit >> shift, true); + + return iova_pfn << shift; +} + +static void vduse_domain_free_iova(struct iova_domain *iovad, + dma_addr_t iova, size_t size) +{ + unsigned long shift = iova_shift(iovad); + unsigned long iova_len = iova_align(iovad, size) >> shift; + + free_iova_fast(iovad, iova >> shift, iova_len); +} + +dma_addr_t vduse_domain_map_page(struct vduse_iova_domain *domain, + struct page *page, unsigned long offset, + size_t size, enum dma_data_direction dir, + unsigned long attrs) +{ + struct iova_domain *iovad = &domain->stream_iovad; + unsigned long limit = domain->bounce_size - 1; + phys_addr_t pa = page_to_phys(page) + offset; + dma_addr_t iova = vduse_domain_alloc_iova(iovad, size, limit); + + if (!iova) + return DMA_MAPPING_ERROR; + + if (vduse_domain_init_bounce_map(domain)) + goto err; + + if (vduse_domain_map_bounce_page(domain, (u64)iova, (u64)size, pa)) + goto err; + + if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL) + vduse_domain_bounce(domain, iova, size, DMA_TO_DEVICE); + + return iova; +err: + vduse_domain_free_iova(iovad, iova, size); + return DMA_MAPPING_ERROR; +} + +void vduse_domain_unmap_page(struct vduse_iova_domain *domain, + dma_addr_t dma_addr, size_t size, + enum dma_data_direction dir, unsigned long attrs) +{ + struct iova_domain *iovad = &domain->stream_iovad; + + if (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL) + vduse_domain_bounce(domain, dma_addr, size, DMA_FROM_DEVICE); + + vduse_domain_unmap_bounce_page(domain, (u64)dma_addr, (u64)size); + vduse_domain_free_iova(iovad, dma_addr, size); +} + +void *vduse_domain_alloc_coherent(struct vduse_iova_domain *domain, + size_t size, dma_addr_t *dma_addr, + gfp_t flag, unsigned long attrs) +{ + struct iova_domain *iovad = &domain->consistent_iovad; + unsigned long limit = domain->iova_limit; + dma_addr_t iova = vduse_domain_alloc_iova(iovad, size, limit); + void *orig = alloc_pages_exact(size, flag); + + if (!iova || !orig) + goto err; + + spin_lock(&domain->iotlb_lock); + if (vduse_iotlb_add_range(domain, (u64)iova, (u64)iova + size - 1, + virt_to_phys(orig), VHOST_MAP_RW, + domain->file, (u64)iova)) { + spin_unlock(&domain->iotlb_lock); + goto err; + } + spin_unlock(&domain->iotlb_lock); + + *dma_addr = iova; + + return orig; +err: + *dma_addr = DMA_MAPPING_ERROR; + if (orig) + free_pages_exact(orig, size); + if (iova) + vduse_domain_free_iova(iovad, iova, size); + + return NULL; +} + +void vduse_domain_free_coherent(struct vduse_iova_domain *domain, size_t size, + void *vaddr, dma_addr_t dma_addr, + unsigned long attrs) +{ + struct iova_domain *iovad = &domain->consistent_iovad; + struct vhost_iotlb_map *map; + struct vdpa_map_file *map_file; + phys_addr_t pa; + + spin_lock(&domain->iotlb_lock); + map = vhost_iotlb_itree_first(domain->iotlb, (u64)dma_addr, + (u64)dma_addr + size - 1); + if (WARN_ON(!map)) { + spin_unlock(&domain->iotlb_lock); + return; + } + map_file = (struct vdpa_map_file *)map->opaque; + fput(map_file->file); + kfree(map_file); + pa = map->addr; + vhost_iotlb_map_free(domain->iotlb, map); + spin_unlock(&domain->iotlb_lock); + + vduse_domain_free_iova(iovad, dma_addr, size); + free_pages_exact(phys_to_virt(pa), size); +} + +static vm_fault_t vduse_domain_mmap_fault(struct vm_fault *vmf) +{ + struct vduse_iova_domain *domain = vmf->vma->vm_private_data; + unsigned long iova = vmf->pgoff << PAGE_SHIFT; + struct page *page; + + if (!domain) + return VM_FAULT_SIGBUS; + + if (iova < domain->bounce_size) + page = vduse_domain_get_bounce_page(domain, iova); + else + page = vduse_domain_get_mapping_page(domain, iova); + + if (!page) + return VM_FAULT_SIGBUS; + + vmf->page = page; + + return 0; +} + +static const struct vm_operations_struct vduse_domain_mmap_ops = { + .fault = vduse_domain_mmap_fault, +}; + +static int vduse_domain_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct vduse_iova_domain *domain = file->private_data; + + vma->vm_flags |= VM_DONTDUMP | VM_DONTEXPAND; + vma->vm_private_data = domain; + vma->vm_ops = &vduse_domain_mmap_ops; + + return 0; +} + +static int vduse_domain_release(struct inode *inode, struct file *file) +{ + struct vduse_iova_domain *domain = file->private_data; + + vduse_domain_reset_bounce_map(domain); + vduse_domain_free_bounce_pages(domain); + put_iova_domain(&domain->stream_iovad); + put_iova_domain(&domain->consistent_iovad); + vhost_iotlb_free(domain->iotlb); + vfree(domain->bounce_maps); + kfree(domain); + + return 0; +} + +static const struct file_operations vduse_domain_fops = { + .mmap = vduse_domain_mmap, + .release = vduse_domain_release, +}; + +void vduse_domain_destroy(struct vduse_iova_domain *domain) +{ + fput(domain->file); +} + +struct vduse_iova_domain * +vduse_domain_create(unsigned long iova_limit, size_t bounce_size) +{ + struct vduse_iova_domain *domain; + struct file *file; + struct vduse_bounce_map *map; + unsigned long pfn, bounce_pfns; + + bounce_pfns = PAGE_ALIGN(bounce_size) >> PAGE_SHIFT; + if (iova_limit <= bounce_size) + return NULL; + + domain = kzalloc(sizeof(*domain), GFP_KERNEL); + if (!domain) + return NULL; + + domain->iotlb = vhost_iotlb_alloc(0, 0); + if (!domain->iotlb) + goto err_iotlb; + + domain->iova_limit = iova_limit; + domain->bounce_size = PAGE_ALIGN(bounce_size); + domain->bounce_maps = vzalloc(bounce_pfns * + sizeof(struct vduse_bounce_map)); + if (!domain->bounce_maps) + goto err_map; + + for (pfn = 0; pfn < bounce_pfns; pfn++) { + map = &domain->bounce_maps[pfn]; + map->orig_phys = INVALID_PHYS_ADDR; + } + file = anon_inode_getfile("[vduse-domain]", &vduse_domain_fops, + domain, O_RDWR); + if (IS_ERR(file)) + goto err_file; + + domain->file = file; + spin_lock_init(&domain->iotlb_lock); + init_iova_domain(&domain->stream_iovad, + PAGE_SIZE, IOVA_START_PFN); + init_iova_domain(&domain->consistent_iovad, + PAGE_SIZE, bounce_pfns); + + return domain; +err_file: + vfree(domain->bounce_maps); +err_map: + vhost_iotlb_free(domain->iotlb); +err_iotlb: + kfree(domain); + return NULL; +} + +int vduse_domain_init(void) +{ + return iova_cache_get(); +} + +void vduse_domain_exit(void) +{ + iova_cache_put(); +} diff --git a/drivers/vdpa/vdpa_user/iova_domain.h b/drivers/vdpa/vdpa_user/iova_domain.h new file mode 100644 index 000000000000..31f822afa5f5 --- /dev/null +++ b/drivers/vdpa/vdpa_user/iova_domain.h @@ -0,0 +1,70 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * MMU-based IOMMU implementation + * + * Copyright (C) 2020-2021 Bytedance Inc. and/or its affiliates. All rights reserved. + * + * Author: Xie Yongji + * + */ + +#ifndef _VDUSE_IOVA_DOMAIN_H +#define _VDUSE_IOVA_DOMAIN_H + +#include +#include +#include + +#define IOVA_START_PFN 1 + +#define INVALID_PHYS_ADDR (~(phys_addr_t)0) + +struct vduse_bounce_map { + struct page *bounce_page; + u64 orig_phys; +}; + +struct vduse_iova_domain { + struct iova_domain stream_iovad; + struct iova_domain consistent_iovad; + struct vduse_bounce_map *bounce_maps; + size_t bounce_size; + unsigned long iova_limit; + int bounce_map; + struct vhost_iotlb *iotlb; + spinlock_t iotlb_lock; + struct file *file; +}; + +int vduse_domain_set_map(struct vduse_iova_domain *domain, + struct vhost_iotlb *iotlb); + +dma_addr_t vduse_domain_map_page(struct vduse_iova_domain *domain, + struct page *page, unsigned long offset, + size_t size, enum dma_data_direction dir, + unsigned long attrs); + +void vduse_domain_unmap_page(struct vduse_iova_domain *domain, + dma_addr_t dma_addr, size_t size, + enum dma_data_direction dir, unsigned long attrs); + +void *vduse_domain_alloc_coherent(struct vduse_iova_domain *domain, + size_t size, dma_addr_t *dma_addr, + gfp_t flag, unsigned long attrs); + +void vduse_domain_free_coherent(struct vduse_iova_domain *domain, size_t size, + void *vaddr, dma_addr_t dma_addr, + unsigned long attrs); + +void vduse_domain_reset_bounce_map(struct vduse_iova_domain *domain); + +void vduse_domain_destroy(struct vduse_iova_domain *domain); + +struct vduse_iova_domain *vduse_domain_create(unsigned long iova_limit, + size_t bounce_size); + +int vduse_domain_init(void); + +void vduse_domain_exit(void); + +#endif /* _VDUSE_IOVA_DOMAIN_H */