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=-14.3 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,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 D60E8C43463 for ; Mon, 21 Sep 2020 12:21:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9AEC0206A4 for ; Mon, 21 Sep 2020 12:21:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="N3amsqzL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727226AbgIUMVQ (ORCPT ); Mon, 21 Sep 2020 08:21:16 -0400 Received: from smtp-fw-9101.amazon.com ([207.171.184.25]:63775 "EHLO smtp-fw-9101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726928AbgIUMVN (ORCPT ); Mon, 21 Sep 2020 08:21:13 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1600690872; x=1632226872; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=FLRGAFMwtehNfQzK+qF9viPQWZpJMVaYe77b115Mz1E=; b=N3amsqzLlVDaekSKbErrrcWjSTDxNAX06Pk59SvgByCJbyMNZU+rBmUE f2eCszhc912McCXYc3RdCfO+VimWnv4/L4Q0WJxyZtFH2PcAKZb4wfdSa mFRc27b3EuKJTUzjzxbhvz36ZS4FwgazoS5YFfJwaslXY1nQKL6bOGIbV c=; X-IronPort-AV: E=Sophos;i="5.77,286,1596499200"; d="scan'208";a="69768501" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-1a-821c648d.us-east-1.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-9101.sea19.amazon.com with ESMTP; 21 Sep 2020 12:21:10 +0000 Received: from EX13D16EUB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan2.iad.amazon.com [10.40.163.34]) by email-inbound-relay-1a-821c648d.us-east-1.amazon.com (Postfix) with ESMTPS id 2B973A2004; Mon, 21 Sep 2020 12:21:07 +0000 (UTC) Received: from 38f9d34ed3b1.ant.amazon.com (10.43.161.71) by EX13D16EUB001.ant.amazon.com (10.43.166.28) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 21 Sep 2020 12:20:57 +0000 From: Andra Paraschiv To: linux-kernel CC: Anthony Liguori , Benjamin Herrenschmidt , Colm MacCarthaigh , "David Duncan" , Bjoern Doebel , "David Woodhouse" , Frank van der Linden , Alexander Graf , Greg KH , "Karen Noel" , Martin Pohlack , Matt Wilson , Paolo Bonzini , Stefano Garzarella , Stefan Hajnoczi , Stewart Smith , Uwe Dannowski , Vitaly Kuznetsov , kvm , ne-devel-upstream , Andra Paraschiv Subject: [PATCH v10 17/18] nitro_enclaves: Add overview documentation Date: Mon, 21 Sep 2020 15:17:31 +0300 Message-ID: <20200921121732.44291-18-andraprs@amazon.com> X-Mailer: git-send-email 2.20.1 (Apple Git-117) In-Reply-To: <20200921121732.44291-1-andraprs@amazon.com> References: <20200921121732.44291-1-andraprs@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.161.71] X-ClientProxiedBy: EX13D06UWC002.ant.amazon.com (10.43.162.205) To EX13D16EUB001.ant.amazon.com (10.43.166.28) Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add documentation on the overview of Nitro Enclaves. Include it in the virtualization specific directory. Changelog v9 -> v10 * Update commit message to include the changelog before the SoB tag(s). v8 -> v9 * Move the Nitro Enclaves documentation to the "virt" directory and add an entry for it in the corresponding index file. v7 -> v8 * Add info about the primary / parent VM CID value. * Update reference link for huge pages. * Add reference link for the x86 boot protocol. * Add license mention and update doc title / chapter formatting. v6 -> v7 * No changes. v5 -> v6 * No changes. v4 -> v5 * No changes. v3 -> v4 * Update doc type from .txt to .rst. * Update documentation based on the changes from v4. v2 -> v3 * No changes. v1 -> v2 * New in v2. Signed-off-by: Andra Paraschiv Reviewed-by: Alexander Graf --- Documentation/virt/index.rst | 1 + Documentation/virt/ne_overview.rst | 95 ++++++++++++++++++++++++++++++ 2 files changed, 96 insertions(+) create mode 100644 Documentation/virt/ne_overview.rst diff --git a/Documentation/virt/index.rst b/Documentation/virt/index.rst index de1ab81df958..e4224305dbef 100644 --- a/Documentation/virt/index.rst +++ b/Documentation/virt/index.rst @@ -11,6 +11,7 @@ Linux Virtualization Support uml/user_mode_linux paravirt_ops guest-halt-polling + ne_overview .. only:: html and subproject diff --git a/Documentation/virt/ne_overview.rst b/Documentation/virt/ne_overview.rst new file mode 100644 index 000000000000..39b0c8fe2654 --- /dev/null +++ b/Documentation/virt/ne_overview.rst @@ -0,0 +1,95 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============== +Nitro Enclaves +============== + +Overview +======== + +Nitro Enclaves (NE) is a new Amazon Elastic Compute Cloud (EC2) capability +that allows customers to carve out isolated compute environments within EC2 +instances [1]. + +For example, an application that processes sensitive data and runs in a VM, +can be separated from other applications running in the same VM. This +application then runs in a separate VM than the primary VM, namely an enclave. + +An enclave runs alongside the VM that spawned it. This setup matches low latency +applications needs. The resources that are allocated for the enclave, such as +memory and CPUs, are carved out of the primary VM. Each enclave is mapped to a +process running in the primary VM, that communicates with the NE driver via an +ioctl interface. + +In this sense, there are two components: + +1. An enclave abstraction process - a user space process running in the primary +VM guest that uses the provided ioctl interface of the NE driver to spawn an +enclave VM (that's 2 below). + +There is a NE emulated PCI device exposed to the primary VM. The driver for this +new PCI device is included in the NE driver. + +The ioctl logic is mapped to PCI device commands e.g. the NE_START_ENCLAVE ioctl +maps to an enclave start PCI command. The PCI device commands are then +translated into actions taken on the hypervisor side; that's the Nitro +hypervisor running on the host where the primary VM is running. The Nitro +hypervisor is based on core KVM technology. + +2. The enclave itself - a VM running on the same host as the primary VM that +spawned it. Memory and CPUs are carved out of the primary VM and are dedicated +for the enclave VM. An enclave does not have persistent storage attached. + +The memory regions carved out of the primary VM and given to an enclave need to +be aligned 2 MiB / 1 GiB physically contiguous memory regions (or multiple of +this size e.g. 8 MiB). The memory can be allocated e.g. by using hugetlbfs from +user space [2][3]. The memory size for an enclave needs to be at least 64 MiB. +The enclave memory and CPUs need to be from the same NUMA node. + +An enclave runs on dedicated cores. CPU 0 and its CPU siblings need to remain +available for the primary VM. A CPU pool has to be set for NE purposes by an +user with admin capability. See the cpu list section from the kernel +documentation [4] for how a CPU pool format looks. + +An enclave communicates with the primary VM via a local communication channel, +using virtio-vsock [5]. The primary VM has virtio-pci vsock emulated device, +while the enclave VM has a virtio-mmio vsock emulated device. The vsock device +uses eventfd for signaling. The enclave VM sees the usual interfaces - local +APIC and IOAPIC - to get interrupts from virtio-vsock device. The virtio-mmio +device is placed in memory below the typical 4 GiB. + +The application that runs in the enclave needs to be packaged in an enclave +image together with the OS ( e.g. kernel, ramdisk, init ) that will run in the +enclave VM. The enclave VM has its own kernel and follows the standard Linux +boot protocol [6]. + +The kernel bzImage, the kernel command line, the ramdisk(s) are part of the +Enclave Image Format (EIF); plus an EIF header including metadata such as magic +number, eif version, image size and CRC. + +Hash values are computed for the entire enclave image (EIF), the kernel and +ramdisk(s). That's used, for example, to check that the enclave image that is +loaded in the enclave VM is the one that was intended to be run. + +These crypto measurements are included in a signed attestation document +generated by the Nitro Hypervisor and further used to prove the identity of the +enclave; KMS is an example of service that NE is integrated with and that checks +the attestation doc. + +The enclave image (EIF) is loaded in the enclave memory at offset 8 MiB. The +init process in the enclave connects to the vsock CID of the primary VM and a +predefined port - 9000 - to send a heartbeat value - 0xb7. This mechanism is +used to check in the primary VM that the enclave has booted. The CID of the +primary VM is 3. + +If the enclave VM crashes or gracefully exits, an interrupt event is received by +the NE driver. This event is sent further to the user space enclave process +running in the primary VM via a poll notification mechanism. Then the user space +enclave process can exit. + +[1] https://aws.amazon.com/ec2/nitro/nitro-enclaves/ +[2] https://www.kernel.org/doc/html/latest/admin-guide/mm/hugetlbpage.html +[3] https://lwn.net/Articles/807108/ +[4] https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html +[5] https://man7.org/linux/man-pages/man7/vsock.7.html +[6] https://www.kernel.org/doc/html/latest/x86/boot.html -- 2.20.1 (Apple Git-117) Amazon Development Center (Romania) S.R.L. registered office: 27A Sf. Lazar Street, UBC5, floor 2, Iasi, Iasi County, 700045, Romania. Registered in Romania. Registration number J22/2621/2005.