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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1B0D6C433F5 for ; Tue, 8 Mar 2022 01:11:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240681AbiCHBMO (ORCPT ); Mon, 7 Mar 2022 20:12:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229906AbiCHBML (ORCPT ); Mon, 7 Mar 2022 20:12:11 -0500 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E72C1B0E; Mon, 7 Mar 2022 17:11:15 -0800 (PST) Received: from kwepemi100015.china.huawei.com (unknown [172.30.72.56]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4KCHHV0Lvxz9sSG; Tue, 8 Mar 2022 09:07:34 +0800 (CST) Received: from kwepemm600005.china.huawei.com (7.193.23.191) by kwepemi100015.china.huawei.com (7.221.188.125) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Tue, 8 Mar 2022 09:11:13 +0800 Received: from [10.67.102.118] (10.67.102.118) by kwepemm600005.china.huawei.com (7.193.23.191) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Tue, 8 Mar 2022 09:11:13 +0800 Subject: Re: [PATCH v8 5/9] hisi_acc_vfio_pci: Restrict access to VF dev BAR2 migration region To: Shameer Kolothum , , , CC: , , , , , , , , , References: <20220303230131.2103-1-shameerali.kolothum.thodi@huawei.com> <20220303230131.2103-6-shameerali.kolothum.thodi@huawei.com> From: liulongfang Message-ID: Date: Tue, 8 Mar 2022 09:11:12 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20220303230131.2103-6-shameerali.kolothum.thodi@huawei.com> Content-Type: text/plain; charset="gbk" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.102.118] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemm600005.china.huawei.com (7.193.23.191) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/3/4 7:01, Shameer Kolothum wrote: > 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 Reviewed-by: Longfang Liu Thanks, Longfang > --- > .../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, >