From patchwork Sat Feb 13 13:29:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Huang, Kai" X-Patchwork-Id: 12086779 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 8E64BC433DB for ; Sat, 13 Feb 2021 13:31:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5A4BA64E44 for ; Sat, 13 Feb 2021 13:31:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229945AbhBMNbd (ORCPT ); Sat, 13 Feb 2021 08:31:33 -0500 Received: from mga12.intel.com ([192.55.52.136]:59259 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229539AbhBMNbD (ORCPT ); Sat, 13 Feb 2021 08:31:03 -0500 IronPort-SDR: AX1PDUJJf9tIwnlhjCgSef8YnLXJpX9wFqf7Jz6TA3RNR/t9TdzP1H8bMBC7tb4PJugCYg5+aX wtH0cgdtUFeg== X-IronPort-AV: E=McAfee;i="6000,8403,9893"; a="161667710" X-IronPort-AV: E=Sophos;i="5.81,176,1610438400"; d="scan'208";a="161667710" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Feb 2021 05:29:52 -0800 IronPort-SDR: 9K4rB2jpGiXpMnEfJvEkGHktm8tVixNZFTqKzGXze0JYCO2VOYCwyd9jDR5ObMsJ+RUO8hjcZX cMwB5gsQy3Ww== X-IronPort-AV: E=Sophos;i="5.81,176,1610438400"; d="scan'208";a="398366059" Received: from kshah-mobl1.amr.corp.intel.com (HELO khuang2-desk.gar.corp.intel.com) ([10.255.230.239]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Feb 2021 05:29:49 -0800 From: Kai Huang To: linux-sgx@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org Cc: seanjc@google.com, jarkko@kernel.org, luto@kernel.org, dave.hansen@intel.com, rick.p.edgecombe@intel.com, haitao.huang@intel.com, pbonzini@redhat.com, bp@alien8.de, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, Kai Huang Subject: [RFC PATCH v5 14/26] x86/sgx: Move provisioning device creation out of SGX driver Date: Sun, 14 Feb 2021 02:29:16 +1300 Message-Id: <94adb11a65cd8a523d1b6b721f94dd8081ed4d5d.1613221549.git.kai.huang@intel.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org From: Sean Christopherson And extract sgx_set_attribute() out of sgx_ioc_enclave_provision() and export it as symbol for KVM to use. Provisioning key is sensitive. SGX driver only allows to create enclave which can access provisioning key when enclave creator has permission to open /dev/sgx_provision. It should apply to VM as well, as provisioning key is platform specific, thus unrestricted VM can also potentially compromise provisioning key. Move provisioning device creation out of sgx_drv_init() to sgx_init() as preparation for adding SGX virtualization support, so that even SGX driver is not enabled due to flexible launch control is not available, SGX virtualization can still be enabled, and use it to restrict VM's capability of being able to access provisioning key. Signed-off-by: Sean Christopherson Reviewed-by: Jarkko Sakkinen Signed-off-by: Kai Huang --- v4->v5: - No code change. v3->v4: - No code change. Added Jarkko's Reviewed-by. v2->v3: - Added kdoc for sgx_set_attribute(), per Jarkko. --- arch/x86/include/asm/sgx.h | 3 ++ arch/x86/kernel/cpu/sgx/driver.c | 17 ---------- arch/x86/kernel/cpu/sgx/ioctl.c | 16 ++------- arch/x86/kernel/cpu/sgx/main.c | 58 +++++++++++++++++++++++++++++++- 4 files changed, 62 insertions(+), 32 deletions(-) diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h index 8a3ea3e1efbe..d67afb051db3 100644 --- a/arch/x86/include/asm/sgx.h +++ b/arch/x86/include/asm/sgx.h @@ -4,6 +4,9 @@ #include +int sgx_set_attribute(unsigned long *allowed_attributes, + unsigned int attribute_fd); + #ifdef CONFIG_X86_SGX_KVM struct sgx_pageinfo; diff --git a/arch/x86/kernel/cpu/sgx/driver.c b/arch/x86/kernel/cpu/sgx/driver.c index f2eac41bb4ff..4f3241109bda 100644 --- a/arch/x86/kernel/cpu/sgx/driver.c +++ b/arch/x86/kernel/cpu/sgx/driver.c @@ -133,10 +133,6 @@ static const struct file_operations sgx_encl_fops = { .get_unmapped_area = sgx_get_unmapped_area, }; -const struct file_operations sgx_provision_fops = { - .owner = THIS_MODULE, -}; - static struct miscdevice sgx_dev_enclave = { .minor = MISC_DYNAMIC_MINOR, .name = "sgx_enclave", @@ -144,13 +140,6 @@ static struct miscdevice sgx_dev_enclave = { .fops = &sgx_encl_fops, }; -static struct miscdevice sgx_dev_provision = { - .minor = MISC_DYNAMIC_MINOR, - .name = "sgx_provision", - .nodename = "sgx_provision", - .fops = &sgx_provision_fops, -}; - int __init sgx_drv_init(void) { unsigned int eax, ebx, ecx, edx; @@ -184,11 +173,5 @@ int __init sgx_drv_init(void) if (ret) return ret; - ret = misc_register(&sgx_dev_provision); - if (ret) { - misc_deregister(&sgx_dev_enclave); - return ret; - } - return 0; } diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c index 1bae754268d1..4714de12422d 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -2,6 +2,7 @@ /* Copyright(c) 2016-20 Intel Corporation. */ #include +#include #include #include #include @@ -664,24 +665,11 @@ static long sgx_ioc_enclave_init(struct sgx_encl *encl, void __user *arg) static long sgx_ioc_enclave_provision(struct sgx_encl *encl, void __user *arg) { struct sgx_enclave_provision params; - struct file *file; if (copy_from_user(¶ms, arg, sizeof(params))) return -EFAULT; - file = fget(params.fd); - if (!file) - return -EINVAL; - - if (file->f_op != &sgx_provision_fops) { - fput(file); - return -EINVAL; - } - - encl->attributes_mask |= SGX_ATTR_PROVISIONKEY; - - fput(file); - return 0; + return sgx_set_attribute(&encl->attributes_mask, params.fd); } long sgx_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index 276220d0e4b5..7167f607d92c 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -1,14 +1,18 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright(c) 2016-20 Intel Corporation. */ +#include #include #include #include +#include #include #include #include #include #include +#include +#include #include "driver.h" #include "encl.h" #include "encls.h" @@ -711,6 +715,51 @@ void sgx_update_lepubkeyhash(u64 *lepubkeyhash) wrmsrl(MSR_IA32_SGXLEPUBKEYHASH0 + i, lepubkeyhash[i]); } +const struct file_operations sgx_provision_fops = { + .owner = THIS_MODULE, +}; + +static struct miscdevice sgx_dev_provision = { + .minor = MISC_DYNAMIC_MINOR, + .name = "sgx_provision", + .nodename = "sgx_provision", + .fops = &sgx_provision_fops, +}; + +/** + * sgx_set_attribute() - Update allowed attributes given file descriptor + * @allowed_attributes: Pointer to allowed enclave attributes + * @attribute_fd: File descriptor for specific attribute + * + * Append enclave attribute indicated by file descriptor to allowed + * attributes. Currently only SGX_ATTR_PROVISIONKEY indicated by + * /dev/sgx_provision is supported. + * + * Return: + * -0: SGX_ATTR_PROVISIONKEY is appended to allowed_attributes + * -EINVAL: Invalid, or not supported file descriptor + */ +int sgx_set_attribute(unsigned long *allowed_attributes, + unsigned int attribute_fd) +{ + struct file *file; + + file = fget(attribute_fd); + if (!file) + return -EINVAL; + + if (file->f_op != &sgx_provision_fops) { + fput(file); + return -EINVAL; + } + + *allowed_attributes |= SGX_ATTR_PROVISIONKEY; + + fput(file); + return 0; +} +EXPORT_SYMBOL_GPL(sgx_set_attribute); + static int __init sgx_init(void) { int ret; @@ -727,6 +776,10 @@ static int __init sgx_init(void) goto err_page_cache; } + ret = misc_register(&sgx_dev_provision); + if (ret) + goto err_kthread; + /* * Always try to initialize the native *and* KVM drivers. * The KVM driver is less picky than the native one and @@ -737,10 +790,13 @@ static int __init sgx_init(void) */ ret = !!sgx_drv_init() & !!sgx_vepc_init(); if (ret) - goto err_kthread; + goto err_provision; return 0; +err_provision: + misc_deregister(&sgx_dev_provision); + err_kthread: kthread_stop(ksgxd_tsk);