From patchwork Fri Feb 26 12:15:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Huang, Kai" X-Patchwork-Id: 12106619 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=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 7D8F9C433E0 for ; Fri, 26 Feb 2021 12:17:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2F72D64EEE for ; Fri, 26 Feb 2021 12:17:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230211AbhBZMR3 (ORCPT ); Fri, 26 Feb 2021 07:17:29 -0500 Received: from mga09.intel.com ([134.134.136.24]:44724 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230402AbhBZMQg (ORCPT ); Fri, 26 Feb 2021 07:16:36 -0500 IronPort-SDR: omurD7Tk9FKZ0v+3uRnLf5I5JD8ruf9+df3OWZ084bY2oEJFx9eMDYA5tR8Fl22UN0lyvYOBdQ K8pd6KgGVkhg== X-IronPort-AV: E=McAfee;i="6000,8403,9906"; a="185980011" X-IronPort-AV: E=Sophos;i="5.81,208,1610438400"; d="scan'208";a="185980011" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Feb 2021 04:15:51 -0800 IronPort-SDR: 2TSK1okdrKleIEdBUqrjUF9JKO1kHd+DdLNqV8gnEnOkuAeYjrza1h5Dg+No/8pqJiVWXhKFv0 mRI031Xij1bQ== X-IronPort-AV: E=Sophos;i="5.81,208,1610438400"; d="scan'208";a="598420606" Received: from ciparjol-mobl.amr.corp.intel.com (HELO khuang2-desk.gar.corp.intel.com) ([10.255.230.175]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Feb 2021 04:15:47 -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 v6 14/25] x86/sgx: Move provisioning device creation out of SGX driver Date: Sat, 27 Feb 2021 01:15:13 +1300 Message-Id: <684c77211acfa1b162d8fbcf507b17d84da5ac11.1614338774.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: kvm@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 Acked-by: Dave Hansen --- v5->v6: - Code change (rebase) due to sgx_arch.h merged to sgx.h. 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 | 57 +++++++++++++++++++++++++++++++- 4 files changed, 61 insertions(+), 32 deletions(-) diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h index d2e1f9a6dd4d..c20df3b37f6c 100644 --- a/arch/x86/include/asm/sgx.h +++ b/arch/x86/include/asm/sgx.h @@ -372,4 +372,7 @@ int sgx_virt_einit(void __user *sigstruct, void __user *token, void __user *secs, u64 *lepubkeyhash, int *trapnr); #endif +int sgx_set_attribute(unsigned long *allowed_attributes, + unsigned int attribute_fd); + #endif /* _ASM_X86_SGX_H */ 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..c70bcdb9ef14 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -1,14 +1,17 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright(c) 2016-20 Intel Corporation. */ +#include #include #include #include +#include #include #include #include #include #include +#include #include "driver.h" #include "encl.h" #include "encls.h" @@ -711,6 +714,51 @@ 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 +775,10 @@ 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 +789,13 @@ 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);