From patchwork Wed Mar 2 17:28:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shameerali Kolothum Thodi X-Patchwork-Id: 12766426 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32411C433F5 for ; Wed, 2 Mar 2022 17:31:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242933AbiCBRbq (ORCPT ); Wed, 2 Mar 2022 12:31:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42310 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243949AbiCBRb3 (ORCPT ); Wed, 2 Mar 2022 12:31:29 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0AC6758811; Wed, 2 Mar 2022 09:30:32 -0800 (PST) Received: from fraeml742-chm.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4K81NG4NTwz67Y1y; Thu, 3 Mar 2022 01:30:22 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml742-chm.china.huawei.com (10.206.15.223) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Wed, 2 Mar 2022 18:30:30 +0100 Received: from A2006125610.china.huawei.com (10.47.91.128) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Wed, 2 Mar 2022 17:30:23 +0000 From: Shameer Kolothum To: , , CC: , , , , , , , , , , Subject: [PATCH v7 05/10] hisi_acc_vfio_pci: Restrict access to VF dev BAR2 migration region Date: Wed, 2 Mar 2022 17:28:58 +0000 Message-ID: <20220302172903.1995-6-shameerali.kolothum.thodi@huawei.com> X-Mailer: git-send-email 2.12.0.windows.1 In-Reply-To: <20220302172903.1995-1-shameerali.kolothum.thodi@huawei.com> References: <20220302172903.1995-1-shameerali.kolothum.thodi@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.47.91.128] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org HiSilicon ACC VF device BAR2 region consists of both functional register space and migration control register space. From a security point of view, it's not advisable to export the migration control region to Guest. Hence, introduce a separate struct vfio_device_ops for migration support which will override the ioctl/read/write/mmap methods to hide the migration region and limit the access only to the functional register space. This will be used in subsequent patches when we add migration support to the driver. Signed-off-by: Shameer Kolothum --- .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 126 ++++++++++++++++++ 1 file changed, 126 insertions(+) diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c index 8129c3457b3b..582ee4fa4109 100644 --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c @@ -13,6 +13,119 @@ #include #include +static int hisi_acc_pci_rw_access_check(struct vfio_device *core_vdev, + size_t count, loff_t *ppos, + size_t *new_count) +{ + unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos); + struct vfio_pci_core_device *vdev = + container_of(core_vdev, struct vfio_pci_core_device, vdev); + + if (index == VFIO_PCI_BAR2_REGION_INDEX) { + loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK; + resource_size_t end = pci_resource_len(vdev->pdev, index) / 2; + + /* Check if access is for migration control region */ + if (pos >= end) + return -EINVAL; + + *new_count = min(count, (size_t)(end - pos)); + } + + return 0; +} + +static int hisi_acc_vfio_pci_mmap(struct vfio_device *core_vdev, + struct vm_area_struct *vma) +{ + struct vfio_pci_core_device *vdev = + container_of(core_vdev, struct vfio_pci_core_device, vdev); + unsigned int index; + + index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT); + if (index == VFIO_PCI_BAR2_REGION_INDEX) { + u64 req_len, pgoff, req_start; + resource_size_t end = pci_resource_len(vdev->pdev, index) / 2; + + req_len = vma->vm_end - vma->vm_start; + pgoff = vma->vm_pgoff & + ((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1); + req_start = pgoff << PAGE_SHIFT; + + if (req_start + req_len > end) + return -EINVAL; + } + + return vfio_pci_core_mmap(core_vdev, vma); +} + +static ssize_t hisi_acc_vfio_pci_write(struct vfio_device *core_vdev, + const char __user *buf, size_t count, + loff_t *ppos) +{ + size_t new_count = count; + int ret; + + ret = hisi_acc_pci_rw_access_check(core_vdev, count, ppos, &new_count); + if (ret) + return ret; + + return vfio_pci_core_write(core_vdev, buf, new_count, ppos); +} + +static ssize_t hisi_acc_vfio_pci_read(struct vfio_device *core_vdev, + char __user *buf, size_t count, + loff_t *ppos) +{ + size_t new_count = count; + int ret; + + ret = hisi_acc_pci_rw_access_check(core_vdev, count, ppos, &new_count); + if (ret) + return ret; + + return vfio_pci_core_read(core_vdev, buf, new_count, ppos); +} + +static long hisi_acc_vfio_pci_ioctl(struct vfio_device *core_vdev, unsigned int cmd, + unsigned long arg) +{ + if (cmd == VFIO_DEVICE_GET_REGION_INFO) { + struct vfio_pci_core_device *vdev = + container_of(core_vdev, struct vfio_pci_core_device, vdev); + struct pci_dev *pdev = vdev->pdev; + struct vfio_region_info info; + unsigned long minsz; + + minsz = offsetofend(struct vfio_region_info, offset); + + if (copy_from_user(&info, (void __user *)arg, minsz)) + return -EFAULT; + + if (info.argsz < minsz) + return -EINVAL; + + if (info.index == VFIO_PCI_BAR2_REGION_INDEX) { + info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index); + + /* + * ACC VF dev BAR2 region consists of both functional + * register space and migration control register space. + * Report only the functional region to Guest. + */ + info.size = pci_resource_len(pdev, info.index) / 2; + + info.flags = VFIO_REGION_INFO_FLAG_READ | + VFIO_REGION_INFO_FLAG_WRITE | + VFIO_REGION_INFO_FLAG_MMAP; + + return copy_to_user((void __user *)arg, &info, minsz) ? + -EFAULT : 0; + } + } + return vfio_pci_core_ioctl(core_vdev, cmd, arg); +} + static int hisi_acc_vfio_pci_open_device(struct vfio_device *core_vdev) { struct vfio_pci_core_device *vdev = @@ -28,6 +141,19 @@ static int hisi_acc_vfio_pci_open_device(struct vfio_device *core_vdev) return 0; } +static const struct vfio_device_ops hisi_acc_vfio_pci_migrn_ops = { + .name = "hisi-acc-vfio-pci-migration", + .open_device = hisi_acc_vfio_pci_open_device, + .close_device = vfio_pci_core_close_device, + .ioctl = hisi_acc_vfio_pci_ioctl, + .device_feature = vfio_pci_core_ioctl_feature, + .read = hisi_acc_vfio_pci_read, + .write = hisi_acc_vfio_pci_write, + .mmap = hisi_acc_vfio_pci_mmap, + .request = vfio_pci_core_request, + .match = vfio_pci_core_match, +}; + static const struct vfio_device_ops hisi_acc_vfio_pci_ops = { .name = "hisi-acc-vfio-pci", .open_device = hisi_acc_vfio_pci_open_device,