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=-9.9 required=3.0 tests=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,USER_AGENT_GIT autolearn=ham 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 2AC36C33CA1 for ; Thu, 9 Jan 2020 14:57:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E8AD32072E for ; Thu, 9 Jan 2020 14:57:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ZNcg2RhU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731902AbgAIO5j (ORCPT ); Thu, 9 Jan 2020 09:57:39 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:51168 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730326AbgAIO5i (ORCPT ); Thu, 9 Jan 2020 09:57:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1578581857; 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=gDGiLHLaS/+Io2Phnnfgd/F37FeteIfvFFEQMfXM9RA=; b=ZNcg2RhUM+bkWQhtWq71Vb+UtJYXGnHaRvCUQpWOXKZjCRbtXIGjUpDgp5JcF7iO+a/yEC A0kC3dp2o+kCM3Qw1aFuKuTrWqcFRHnBbaBXVxKl4ZlVKjfOiEzL5hqSvm3IK522QOLT4Q g+MWpFpKFwBttkMt5hFwLBZ7nYMcjbo= Received: from mail-qt1-f197.google.com (mail-qt1-f197.google.com [209.85.160.197]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-45-4eRYJZdnO5Gx667P3eHuaQ-1; Thu, 09 Jan 2020 09:57:36 -0500 X-MC-Unique: 4eRYJZdnO5Gx667P3eHuaQ-1 Received: by mail-qt1-f197.google.com with SMTP id l5so4360295qte.10 for ; Thu, 09 Jan 2020 06:57:35 -0800 (PST) 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=gDGiLHLaS/+Io2Phnnfgd/F37FeteIfvFFEQMfXM9RA=; b=Pgc2aTJbfxy+DCV+W43oDUrRBrtRoCtqxiLQt+rZZ2LW9Ecb//OvlfLFzyIHosrbhu mgSLuwsujukTnRiO7MVTBhIrab7jxBH5TRkw0827R53+flJ+76O0C3a2M55KRIpj45HH +ukPjU5+n8q63MfANAwyfbUJ3Zpj9/16OYKPpqojCXYeThu4FXHZ4xdFucdLCaxPZhc2 7GhiyzEvaW0+6jvr5JsgIhWbiny0HKSLd4JkuBfm3mx5dFxXy4Sllppr2cuy/vG93Gfb P07VVc/JQrpfo/8QjWFU1Ygpv+pbwIvUjYCeGDI8V6un7paufsoaWQb0J/AhWUEnMzZn 3FVA== X-Gm-Message-State: APjAAAVaghKcdQpjlGjN/ITtawu40PNGyHgnShx0NWW5EZwGMj7r5bgG QIzZ7uwHg3XcScgQKFlwNhtgTxC1w4IdyDFCe+eE37Fcz2pP5Xow4G0hFS6eoETcUW0kM2Gazdl MPN+4/mM5m9xz/uYGhprbpaXv X-Received: by 2002:a05:620a:102e:: with SMTP id a14mr9510825qkk.159.1578581855560; Thu, 09 Jan 2020 06:57:35 -0800 (PST) X-Google-Smtp-Source: APXvYqw9fW22cpWNa0ej5q9Tvxem01vg3v97AmZT7K2M9MRr1qsTUoG9MFfgUMx1bfEecySbeqsNlQ== X-Received: by 2002:a05:620a:102e:: with SMTP id a14mr9510799qkk.159.1578581855290; Thu, 09 Jan 2020 06:57:35 -0800 (PST) Received: from xz-x1.yyz.redhat.com ([104.156.64.74]) by smtp.gmail.com with ESMTPSA id q2sm3124179qkm.5.2020.01.09.06.57.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Jan 2020 06:57:33 -0800 (PST) From: Peter Xu To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Christophe de Dinechin , "Michael S . Tsirkin" , Paolo Bonzini , Sean Christopherson , Yan Zhao , Alex Williamson , Jason Wang , Kevin Kevin , Vitaly Kuznetsov , peterx@redhat.com, "Dr . David Alan Gilbert" Subject: [PATCH v3 01/21] vfio: introduce vfio_iova_rw to read/write a range of IOVAs Date: Thu, 9 Jan 2020 09:57:09 -0500 Message-Id: <20200109145729.32898-2-peterx@redhat.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200109145729.32898-1-peterx@redhat.com> References: <20200109145729.32898-1-peterx@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yan Zhao vfio_iova_rw will read/write a range of userspace memory (starting form device iova to iova + len -1) into a kenrel buffer without pinning the userspace memory. TODO: vfio needs to mark the iova dirty if vfio_iova_rw(write) is called. Cc: Kevin Tian Signed-off-by: Yan Zhao Signed-off-by: Peter Xu --- drivers/vfio/vfio.c | 45 ++++++++++++++++++ drivers/vfio/vfio_iommu_type1.c | 81 +++++++++++++++++++++++++++++++++ include/linux/vfio.h | 5 ++ 3 files changed, 131 insertions(+) diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index c8482624ca34..36e91e647ed5 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -1961,6 +1961,51 @@ int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn, int npage) } EXPORT_SYMBOL(vfio_unpin_pages); +/* + * Read/Write a range of userspace IOVAs for a device into/from a kernel + * buffer without pinning the userspace memory + * @dev [in] : device + * @iova [in] : base IOVA of a userspace buffer + * @data [in] : pointer to kernel buffer + * @len [in] : kernel buffer length + * @write : indicate read or write + * Return error on failure or 0 on success. + */ +int vfio_iova_rw(struct device *dev, unsigned long iova, void *data, + unsigned long len, bool write) +{ + struct vfio_container *container; + struct vfio_group *group; + struct vfio_iommu_driver *driver; + int ret = 0; + + if (!dev || !data || len <= 0) + 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->iova_rw)) + ret = driver->ops->iova_rw(container->iommu_data, + iova, data, len, write); + else + ret = -ENOTTY; + + vfio_group_try_dissolve_container(group); +out: + vfio_group_put(group); + return ret; +} +EXPORT_SYMBOL(vfio_iova_rw); + static int vfio_register_iommu_notifier(struct vfio_group *group, unsigned long *events, struct notifier_block *nb) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 2ada8e6cdb88..aee191077235 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include #include @@ -2326,6 +2327,85 @@ static int vfio_iommu_type1_unregister_notifier(void *iommu_data, return blocking_notifier_chain_unregister(&iommu->notifier, nb); } +static int next_segment(unsigned long len, int offset) +{ + if (len > PAGE_SIZE - offset) + return PAGE_SIZE - offset; + else + return len; +} + +static int vfio_iommu_type1_rw_iova_seg(struct vfio_iommu *iommu, + unsigned long iova, void *data, + unsigned long seg_len, + unsigned long offset, + bool write) +{ + struct mm_struct *mm; + unsigned long vaddr; + struct vfio_dma *dma; + bool kthread = current->mm == NULL; + int ret = 0; + + dma = vfio_find_dma(iommu, iova, PAGE_SIZE); + if (!dma) + return -EINVAL; + + mm = get_task_mm(dma->task); + + if (!mm) + return -ENODEV; + + if (kthread) + use_mm(mm); + else if (current->mm != mm) { + ret = -EINVAL; + goto out; + } + + vaddr = dma->vaddr + iova - dma->iova + offset; + + ret = write ? __copy_to_user((void __user *)vaddr, + data, seg_len) : + __copy_from_user(data, (void __user *)vaddr, + seg_len); + if (ret) + ret = -EFAULT; + + if (kthread) + unuse_mm(mm); +out: + mmput(mm); + return ret; +} + +static int vfio_iommu_type1_iova_rw(void *iommu_data, unsigned long iova, + void *data, unsigned long len, bool write) +{ + struct vfio_iommu *iommu = iommu_data; + int offset = iova & ~PAGE_MASK; + int seg_len; + int ret = 0; + + iova = iova & PAGE_MASK; + + mutex_lock(&iommu->lock); + while ((seg_len = next_segment(len, offset)) > 0) { + ret = vfio_iommu_type1_rw_iova_seg(iommu, iova, data, + seg_len, offset, write); + if (ret) + break; + + offset = 0; + len -= seg_len; + data += seg_len; + iova += PAGE_SIZE; + } + + mutex_unlock(&iommu->lock); + return ret; +} + static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = { .name = "vfio-iommu-type1", .owner = THIS_MODULE, @@ -2338,6 +2418,7 @@ static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = { .unpin_pages = vfio_iommu_type1_unpin_pages, .register_notifier = vfio_iommu_type1_register_notifier, .unregister_notifier = vfio_iommu_type1_unregister_notifier, + .iova_rw = vfio_iommu_type1_iova_rw, }; static int __init vfio_iommu_type1_init(void) diff --git a/include/linux/vfio.h b/include/linux/vfio.h index e42a711a2800..7bf18a31bbcf 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -82,6 +82,8 @@ struct vfio_iommu_driver_ops { struct notifier_block *nb); int (*unregister_notifier)(void *iommu_data, struct notifier_block *nb); + int (*iova_rw)(void *iommu_data, unsigned long iova, + void *data, unsigned long len, bool write); }; extern int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops); @@ -107,6 +109,9 @@ extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn, int npage); +extern int vfio_iova_rw(struct device *dev, unsigned long iova, void *data, + unsigned long len, bool write); + /* each type has independent events */ enum vfio_notify_type { VFIO_IOMMU_NOTIFY = 0, -- 2.24.1