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=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 24C03C07E97 for ; Fri, 2 Jul 2021 20:29:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0ECFE613BC for ; Fri, 2 Jul 2021 20:29:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231587AbhGBUcP (ORCPT ); Fri, 2 Jul 2021 16:32:15 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:45510 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230447AbhGBUcN (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=1625257781; 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=PwpVO4SWPwy4ZIgZB5lf2AyVvgwpNXrWMtJOK+i0Wg4Ui0k4II/KKDlU1pG1lC+wWfgPwP wSxXjKjobvJGrSWUwbM053mMXc3Gk8MiDzw0319o9isuGMEbhxLZRn7AGSwWcTqa/HYjBY vSoPhl/C56PPWcLgyBUN6cE0ywHb8oY= Received: from mail-ot1-f71.google.com (mail-ot1-f71.google.com [209.85.210.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-52-kM1pE99xPGKIG4AKEhBiIQ-1; Fri, 02 Jul 2021 16:29:39 -0400 X-MC-Unique: kM1pE99xPGKIG4AKEhBiIQ-1 Received: by mail-ot1-f71.google.com with SMTP id q20-20020a9d7c940000b02903f5a4101f8eso6924700otn.17 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=GStIXjOHutmGuIket28JaaD6VC8zPKwvwn00669n+xo1b3oTCH/bKtNx7rLvlzTbRm qXklXwmvHyb+5bz140g3NS3Zyn3gQSUot8AGXlKtlNKn9QQVUYBWi79dpK/MdeumzRgR KKeYhZbQ0bz1+pvOLqBjNmNEaRF4Wym1M4r3bh/DOc2oRjK2sEWjP2/KRg7nJMj1+EiO ME89gAJ8oi9NCyvOJUcFY7OqzemNqvSLLrYtVlvzGqwLPNDCtFSJyakQSO6al0BTECb9 OoYcJ5FcF5ZvZ2PhRnesYrVidx5Gq1KGkQssXoFIrj/GZkrVeSjz8ebK2NFMoWqIREd4 LKIQ== X-Gm-Message-State: AOAM532xwWp2K0D5L/apgINIbNnQ6NBY7gLwGwkCAN8AZDCizPBc00rn 6IJs/8/7PcGbBAx7Xkj6AtEb7FrUGE8yaKTy/f7BLx0/Ma5qA6d8wVRze/1r5WapzINdwDtjtLp 1WCJTt6QL13KV0pc4dEuABIZC X-Received: by 2002:aca:3bc3:: with SMTP id i186mr1209796oia.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: linux-kernel@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,