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=-17.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 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 A5C10C07E95 for ; Fri, 2 Jul 2021 20:29:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8939561410 for ; Fri, 2 Jul 2021 20:29:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231127AbhGBUcN (ORCPT ); Fri, 2 Jul 2021 16:32:13 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:40363 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231137AbhGBUcN (ORCPT ); Fri, 2 Jul 2021 16:32:13 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1625257780; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=43m9ZMNlwSNeKVrq0tRO/O1TR5j/lIl0glWtuE7KCzs=; b=jV3gUdG67XzJ3bQmBBI8AYDHyU7OZXFmjCLP5FKhuFo6B6sQyF3yy/DjYchS/Ti41eJ8rv op5zJA6+awWMPWrOSujE6TM2hiYrLcagbFME0JK1LPnSmnNumwER1ADHIKVDnTzQFB6poR WN+gEO+rKtQzMJ5RG0Y9pkod+wR8/Uo= Received: from mail-oi1-f198.google.com (mail-oi1-f198.google.com [209.85.167.198]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-36-HhTcoXIzNUKNInkuzf4h_Q-1; Fri, 02 Jul 2021 16:29:39 -0400 X-MC-Unique: HhTcoXIzNUKNInkuzf4h_Q-1 Received: by mail-oi1-f198.google.com with SMTP id b18-20020acafd120000b029023d714b710fso6270157oii.4 for ; Fri, 02 Jul 2021 13:29:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=43m9ZMNlwSNeKVrq0tRO/O1TR5j/lIl0glWtuE7KCzs=; b=EUKz/dRr7rKwD3q0hvJaVSeytHCmGPsh+yzDT5bDfAmzfnl2N+tHVnkCfTWBwHW40s q6rsBTKZA/rEJEy4sj7N7/7eGrxbzfJpJqL9dHH6sAJ+kEwj0vqkz3CvjqJjlldZhOtL EB9lpiVsaQ3wCFM0Haeya3dU2QcsIXLJ8ej9KeoQ+vj3HdS+KJiwKP+e+mkTjRDsj+Jg TvxL89SOdiDrT+O5bWBkFMb5MJv3hQxDpJ/9WsOLY5qrFe0QtYfpK/RT8n/RRcZ9Sjqv oSYru7S1ulR1AHLQGX6/m4Mi2Y6MtzbAzndPdf2lZ7JQo3HGAgJbFEotVsV7rWDRbB3I e0rQ== X-Gm-Message-State: AOAM533F4JLzUoQxXjmOx3hWZg1krbXhq6gX6xwKdG3Hgm/s1UPdUQft 6Y9Sovd0hFdIbWUGXeCgHJnjXjj+SApR9Zyr3vfv4kXuwezDt9NOGFFF8l0KxQpcT2ryqIRSBVc KQwokLvz48IAU X-Received: by 2002:aca:3bc3:: with SMTP id i186mr1209797oia.102.1625257778612; Fri, 02 Jul 2021 13:29:38 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzJGZxdvdDgbA5jf/eA3mNAUGNVwqo/oKw3QtnN938999lHw9G7kVlYyunnUZrw5ODGPAbp+Q== X-Received: by 2002:aca:3bc3:: with SMTP id i186mr1209778oia.102.1625257778458; Fri, 02 Jul 2021 13:29:38 -0700 (PDT) Received: from redhat.com ([198.99.80.109]) by smtp.gmail.com with ESMTPSA id o45sm788385ota.59.2021.07.02.13.29.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 02 Jul 2021 13:29:38 -0700 (PDT) Date: Fri, 2 Jul 2021 14:29:37 -0600 From: Alex Williamson To: Shameer Kolothum Cc: , , , , , , , , , , Subject: Re: [RFC v2 2/4] hisi_acc_vfio_pci: Override ioctl method to limit BAR2 region size Message-ID: <20210702142937.5cbe366f.alex.williamson@redhat.com> In-Reply-To: <20210702095849.1610-3-shameerali.kolothum.thodi@huawei.com> References: <20210702095849.1610-1-shameerali.kolothum.thodi@huawei.com> <20210702095849.1610-3-shameerali.kolothum.thodi@huawei.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, 2 Jul 2021 10:58:47 +0100 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, hide the migration region and report only the functional register > space. > > Signed-off-by: Shameer Kolothum > --- > drivers/vfio/pci/hisi_acc_vfio_pci.c | 42 +++++++++++++++++++++++++++- > 1 file changed, 41 insertions(+), 1 deletion(-) > > diff --git a/drivers/vfio/pci/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisi_acc_vfio_pci.c > index a9e173098ab5..d57cf6d7adaf 100644 > --- a/drivers/vfio/pci/hisi_acc_vfio_pci.c > +++ b/drivers/vfio/pci/hisi_acc_vfio_pci.c > @@ -12,6 +12,46 @@ > #include > #include > > +static long hisi_acc_vfio_pci_ioctl(struct vfio_device *core_vdev, unsigned int cmd, > + unsigned long arg) > +{ > + struct vfio_pci_core_device *vdev = > + container_of(core_vdev, struct vfio_pci_core_device, vdev); > + > + if (cmd == VFIO_DEVICE_GET_REGION_INFO) { > + 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(64K) consists of both functional > + * register space and migration control register space. > + * Report only the first 32K(functional region) to Guest. > + */ > + info.size = pci_resource_len(pdev, info.index) / 2; > + Great, but what actually prevents the user from accessing the full extent of the BAR since you're re-using core code for read/write/mmap, which are all basing access on pci_resource_len()? Thanks, Alex > + 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(struct vfio_device *core_vdev) > { > struct vfio_pci_core_device *vdev = > @@ -33,7 +73,7 @@ static const struct vfio_device_ops hisi_acc_vfio_pci_ops = { > .name = "hisi-acc-vfio-pci", > .open = hisi_acc_vfio_pci_open, > .release = vfio_pci_core_release, > - .ioctl = vfio_pci_core_ioctl, > + .ioctl = hisi_acc_vfio_pci_ioctl, > .read = vfio_pci_core_read, > .write = vfio_pci_core_write, > .mmap = vfio_pci_core_mmap,