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=-10.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 E7546C43460 for ; Fri, 23 Apr 2021 08:10:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A2D32613CD for ; Fri, 23 Apr 2021 08:10:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241212AbhDWIKu (ORCPT ); Fri, 23 Apr 2021 04:10:50 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:59323 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229917AbhDWIKt (ORCPT ); Fri, 23 Apr 2021 04:10:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619165412; 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; bh=Pc9kV6aoLVJwEsHfUpicjnbTw0ZNIpHRhnJgCa+FrJA=; b=OtEv4XoTxMJQhpqtfkWCUNClYEEkLIYt+cqWjWO6/bOHfp8BriF87Ib7ofu+ICmfb66a1/ NddbT+U9I476oTfBjfinzjYLN55LsdduLpnpHqXAKcvWr1OacPNN4nBSATYSf5FYDKoUEn S/tKHaQs3v2kGCClljNIWvkbcR8vRGg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-414-j7lbdBtfOrKGXOLEB8R-Vw-1; Fri, 23 Apr 2021 04:10:08 -0400 X-MC-Unique: j7lbdBtfOrKGXOLEB8R-Vw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0A2D484BA42; Fri, 23 Apr 2021 08:10:07 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-225.pek2.redhat.com [10.72.13.225]) by smtp.corp.redhat.com (Postfix) with ESMTP id A28A25C6DE; Fri, 23 Apr 2021 08:09:44 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, xieyongji@bytedance.com, stefanha@redhat.com, file@sect.tu-berlin.de, ashish.kalra@amd.com, konrad.wilk@oracle.com, kvm@vger.kernel.org, hch@infradead.org Subject: [RFC PATCH V2 0/7] Do not read from descripto ring Date: Fri, 23 Apr 2021 16:09:35 +0800 Message-Id: <20210423080942.2997-1-jasowang@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi: Sometimes, the driver doesn't trust the device. This is usually happens for the encrtpyed VM or VDUSE[1]. In both cases, technology like swiotlb is used to prevent the poking/mangling of memory from the device. But this is not sufficient since current virtio driver may trust what is stored in the descriptor table (coherent mapping) for performing the DMA operations like unmap and bounce so the device may choose to utilize the behaviour of swiotlb to perform attacks[2]. To protect from a malicous device, this series store and use the descriptor metadata in an auxiliay structure which can not be accessed via swiotlb instead of the ones in the descriptor table. This means the descriptor table is write-only from the view of the driver. Actually, we've almost achieved that through packed virtqueue and we just need to fix a corner case of handling mapping errors. For split virtqueue we just follow what's done in the packed. Note that we don't duplicate descriptor medata for indirect descriptors since it uses stream mapping which is read only so it's safe if the metadata of non-indirect descriptors are correct. For split virtqueue, the change increase the footprint due the the auxiliary metadata but it's almost neglectlable in the simple test like pktgen or netpef. Slightly tested with packed on/off, iommu on/of, swiotlb force/off in the guest. Please review. Changes from V1: - Always use auxiliary metadata for split virtqueue - Don't read from descripto when detaching indirect descriptor [1] https://lore.kernel.org/netdev/fab615ce-5e13-a3b3-3715-a4203b4ab010@redhat.com/T/ [2] https://yhbt.net/lore/all/c3629a27-3590-1d9f-211b-c0b7be152b32@redhat.com/T/#mc6b6e2343cbeffca68ca7a97e0f473aaa871c95b Jason Wang (7): virtio-ring: maintain next in extra state for packed virtqueue virtio_ring: rename vring_desc_extra_packed virtio-ring: factor out desc_extra allocation virtio_ring: secure handling of mapping errors virtio_ring: introduce virtqueue_desc_add_split() virtio: use err label in __vring_new_virtqueue() virtio-ring: store DMA metadata in desc_extra for split virtqueue drivers/virtio/virtio_ring.c | 201 +++++++++++++++++++++++++---------- 1 file changed, 144 insertions(+), 57 deletions(-) -- 2.25.1 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=-8.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 65C6FC433B4 for ; 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Fri, 23 Apr 2021 08:10:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619165412; 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; bh=Pc9kV6aoLVJwEsHfUpicjnbTw0ZNIpHRhnJgCa+FrJA=; b=OtEv4XoTxMJQhpqtfkWCUNClYEEkLIYt+cqWjWO6/bOHfp8BriF87Ib7ofu+ICmfb66a1/ NddbT+U9I476oTfBjfinzjYLN55LsdduLpnpHqXAKcvWr1OacPNN4nBSATYSf5FYDKoUEn S/tKHaQs3v2kGCClljNIWvkbcR8vRGg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-414-j7lbdBtfOrKGXOLEB8R-Vw-1; Fri, 23 Apr 2021 04:10:08 -0400 X-MC-Unique: j7lbdBtfOrKGXOLEB8R-Vw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0A2D484BA42; Fri, 23 Apr 2021 08:10:07 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-225.pek2.redhat.com [10.72.13.225]) by smtp.corp.redhat.com (Postfix) with ESMTP id A28A25C6DE; Fri, 23 Apr 2021 08:09:44 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com Subject: [RFC PATCH V2 0/7] Do not read from descripto ring Date: Fri, 23 Apr 2021 16:09:35 +0800 Message-Id: <20210423080942.2997-1-jasowang@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Cc: ashish.kalra@amd.com, file@sect.tu-berlin.de, kvm@vger.kernel.org, konrad.wilk@oracle.com, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, hch@infradead.org, xieyongji@bytedance.com, stefanha@redhat.com X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" Hi: Sometimes, the driver doesn't trust the device. This is usually happens for the encrtpyed VM or VDUSE[1]. In both cases, technology like swiotlb is used to prevent the poking/mangling of memory from the device. But this is not sufficient since current virtio driver may trust what is stored in the descriptor table (coherent mapping) for performing the DMA operations like unmap and bounce so the device may choose to utilize the behaviour of swiotlb to perform attacks[2]. To protect from a malicous device, this series store and use the descriptor metadata in an auxiliay structure which can not be accessed via swiotlb instead of the ones in the descriptor table. This means the descriptor table is write-only from the view of the driver. Actually, we've almost achieved that through packed virtqueue and we just need to fix a corner case of handling mapping errors. For split virtqueue we just follow what's done in the packed. Note that we don't duplicate descriptor medata for indirect descriptors since it uses stream mapping which is read only so it's safe if the metadata of non-indirect descriptors are correct. For split virtqueue, the change increase the footprint due the the auxiliary metadata but it's almost neglectlable in the simple test like pktgen or netpef. Slightly tested with packed on/off, iommu on/of, swiotlb force/off in the guest. Please review. Changes from V1: - Always use auxiliary metadata for split virtqueue - Don't read from descripto when detaching indirect descriptor [1] https://lore.kernel.org/netdev/fab615ce-5e13-a3b3-3715-a4203b4ab010@redhat.com/T/ [2] https://yhbt.net/lore/all/c3629a27-3590-1d9f-211b-c0b7be152b32@redhat.com/T/#mc6b6e2343cbeffca68ca7a97e0f473aaa871c95b Jason Wang (7): virtio-ring: maintain next in extra state for packed virtqueue virtio_ring: rename vring_desc_extra_packed virtio-ring: factor out desc_extra allocation virtio_ring: secure handling of mapping errors virtio_ring: introduce virtqueue_desc_add_split() virtio: use err label in __vring_new_virtqueue() virtio-ring: store DMA metadata in desc_extra for split virtqueue drivers/virtio/virtio_ring.c | 201 +++++++++++++++++++++++++---------- 1 file changed, 144 insertions(+), 57 deletions(-) -- 2.25.1 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization