From patchwork Mon Jan 18 03:28:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kai Huang X-Patchwork-Id: 12026379 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 042D2C433DB for ; Mon, 18 Jan 2021 03:29:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C6D32224B1 for ; Mon, 18 Jan 2021 03:29:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731687AbhARD31 (ORCPT ); Sun, 17 Jan 2021 22:29:27 -0500 Received: from mga18.intel.com ([134.134.136.126]:60995 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731683AbhARD3V (ORCPT ); Sun, 17 Jan 2021 22:29:21 -0500 IronPort-SDR: EOybH/EI6pnY4WTOPB8tCyoRmzhgivZ4lPZo5zcYl67N2n/FNnFVwEKoXkVNobi3IrnXvfrI4f uryRpHWmzaAA== X-IronPort-AV: E=McAfee;i="6000,8403,9867"; a="166420880" X-IronPort-AV: E=Sophos;i="5.79,355,1602572400"; d="scan'208";a="166420880" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jan 2021 19:28:31 -0800 IronPort-SDR: NQepSmyI5tr9Sp9MBh30H4/zJk5eegDk7ztEnKT925lzETntfSpRpsT/8TSKuDflxY1/xYurF9 9Qpd2OxhPF4g== X-IronPort-AV: E=Sophos;i="5.79,355,1602572400"; d="scan'208";a="573151030" Received: from amrahman-mobl.amr.corp.intel.com (HELO khuang2-desk.gar.corp.intel.com) ([10.252.142.253]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jan 2021 19:28:28 -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, haitao.huang@intel.com, pbonzini@redhat.com, bp@alien8.de, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, Kai Huang Subject: [RFC PATCH v2 13/26] x86/sgx: Add helpers to expose ECREATE and EINIT to KVM Date: Mon, 18 Jan 2021 16:28:06 +1300 Message-Id: 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 The bare-metal kernel must intercept ECREATE to be able to impose policies on guests. When it does this, the bare-metal kernel runs ECREATE against the userspace mapping of the virtualized EPC. Provide wrappers around __ecreate() and __einit() to hide the ugliness of overloading the ENCLS return value to encode multiple error formats in a single int. KVM will trap-and-execute ECREATE and EINIT as part of SGX virtualization, and on an exception, KVM needs the trapnr so that it can inject the correct fault into the guest. Signed-off-by: Sean Christopherson [Kai: Use sgx_update_lepubkeyhash() to update pubkey hash MSRs.] Signed-off-by: Kai Huang --- v1->v2: - Refined commit msg based on Dave's comment. - Added comment to explain why to use __uaccess_xxx(). --- arch/x86/include/asm/sgx.h | 16 +++++++++ arch/x86/kernel/cpu/sgx/virt.c | 61 ++++++++++++++++++++++++++++++++++ 2 files changed, 77 insertions(+) create mode 100644 arch/x86/include/asm/sgx.h diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h new file mode 100644 index 000000000000..0d643b985085 --- /dev/null +++ b/arch/x86/include/asm/sgx.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_SGX_H +#define _ASM_X86_SGX_H + +#include + +#ifdef CONFIG_X86_SGX_VIRTUALIZATION +struct sgx_pageinfo; + +int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs, + int *trapnr); +int sgx_virt_einit(void __user *sigstruct, void __user *token, + void __user *secs, u64 *lepubkeyhash, int *trapnr); +#endif + +#endif /* _ASM_X86_SGX_H */ diff --git a/arch/x86/kernel/cpu/sgx/virt.c b/arch/x86/kernel/cpu/sgx/virt.c index 1e8620f20651..97f02e5235ca 100644 --- a/arch/x86/kernel/cpu/sgx/virt.c +++ b/arch/x86/kernel/cpu/sgx/virt.c @@ -253,3 +253,64 @@ int __init sgx_virt_epc_init(void) return misc_register(&sgx_virt_epc_dev); } + +int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs, + int *trapnr) +{ + int ret; + + /* + * @secs is userspace address, and it's not guaranteed @secs points at + * an actual EPC page. It's also possible to generate a kernel mapping + * to physical EPC page by resolving PFN but using __uaccess_xx() is + * simpler. + */ + __uaccess_begin(); + ret = __ecreate(pageinfo, (void *)secs); + __uaccess_end(); + + if (encls_faulted(ret)) { + *trapnr = ENCLS_TRAPNR(ret); + return -EFAULT; + } + + /* ECREATE doesn't return an error code, it faults or succeeds. */ + WARN_ON_ONCE(ret); + return 0; +} +EXPORT_SYMBOL_GPL(sgx_virt_ecreate); + +static int __sgx_virt_einit(void __user *sigstruct, void __user *token, + void __user *secs) +{ + int ret; + + __uaccess_begin(); + ret = __einit((void *)sigstruct, (void *)token, (void *)secs); + __uaccess_end(); + return ret; +} + +int sgx_virt_einit(void __user *sigstruct, void __user *token, + void __user *secs, u64 *lepubkeyhash, int *trapnr) +{ + int ret; + + if (!boot_cpu_has(X86_FEATURE_SGX_LC)) { + ret = __sgx_virt_einit(sigstruct, token, secs); + } else { + preempt_disable(); + + sgx_update_lepubkeyhash(lepubkeyhash); + + ret = __sgx_virt_einit(sigstruct, token, secs); + preempt_enable(); + } + + if (encls_faulted(ret)) { + *trapnr = ENCLS_TRAPNR(ret); + return -EFAULT; + } + return ret; +} +EXPORT_SYMBOL_GPL(sgx_virt_einit);