From patchwork Fri May 20 10:39:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Zhang, Cathy" X-Patchwork-Id: 12856622 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F3A2C433FE for ; Fri, 20 May 2022 10:41:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348236AbiETKlo (ORCPT ); Fri, 20 May 2022 06:41:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49972 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348270AbiETKlU (ORCPT ); Fri, 20 May 2022 06:41:20 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A3F2815829 for ; Fri, 20 May 2022 03:41:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1653043278; x=1684579278; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=BEGZ3fQmZqUPI1ggNe8u4t/fGxRle1nwcPGCJ/MDG+k=; b=JFsV90i58Z+QWmqyI5MYens0JRiXhjfF1N/j1rD7ru0Qga6y9U3RveUT UjAlwkJmT7a81mLxz+3Vctbync8j1OG/Jh+e/SVUMCMpknuGynJOXuYz3 5pUNVwDof5hvZP3s9of8LyPRa6I/qFLtDbCigNCvHzCx1HsZzqqEVMHX5 /UtGxSiz/x7q38sWefKPweq4evMhctkuujBqGFam8fH2wIa5vWlbNAjhX KwJAPRj7yANOARytd+HNpaHAsAHYMUqY4xrmPxMbIj8aRrnJ4UDOOR5w8 rzW3jNFW1cph0rFhxYTfJtcGVNpKLa4EWWr2kBk1siVl6N7OxfAAkHX/C g==; X-IronPort-AV: E=McAfee;i="6400,9594,10352"; a="271386989" X-IronPort-AV: E=Sophos;i="5.91,238,1647327600"; d="scan'208";a="271386989" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 May 2022 03:41:18 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.91,238,1647327600"; d="scan'208";a="715471047" Received: from cathy-vostro-3670.bj.intel.com ([10.238.156.128]) by fmsmga001.fm.intel.com with ESMTP; 20 May 2022 03:41:15 -0700 From: Cathy Zhang To: linux-sgx@vger.kernel.org, x86@kernel.org Cc: jarkko@kernel.org, reinette.chatre@intel.com, dave.hansen@intel.com, ashok.raj@intel.com, cathy.zhang@intel.com, chao.p.peng@linux.intel.com, yang.zhong@intel.com Subject: [PATCH v5 7/9] x86/sgx: Implement ENCLS[EUPDATESVN] Date: Fri, 20 May 2022 18:39:02 +0800 Message-Id: <20220520103904.1216-8-cathy.zhang@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220520103904.1216-1-cathy.zhang@intel.com> References: <20220520103904.1216-1-cathy.zhang@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org The SGX attestation architecture assumes a compromise of all running enclaves and cryptographic assets (like internal SGX encryption keys) whenever a microcode update affects SGX. To mitigate the impact of this presumed compromise, a new supervisor SGX instruction: ENCLS[EUPDATESVN], is introduced to update SGX microcode version and generate new cryptographic assets in runtime after SGX microcode update. EUPDATESVN requires that SGX memory to be marked as "unused" before it will succeed. This ensures that no compromised enclave can survive the process and provides an opportunity to generate new cryptographic assets. Signed-off-by: Cathy Zhang --- Changes since v1: - Print message for each return code to notify userspace the ENCLS[EUPDATESVN] execution status. --- arch/x86/include/asm/sgx.h | 33 +++++++++++---------- arch/x86/kernel/cpu/sgx/encls.h | 6 ++++ arch/x86/kernel/cpu/sgx/main.c | 52 +++++++++++++++++++++++++++++++++ 3 files changed, 76 insertions(+), 15 deletions(-) diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h index 4a8ca7281229..74bcb6841a4b 100644 --- a/arch/x86/include/asm/sgx.h +++ b/arch/x86/include/asm/sgx.h @@ -26,23 +26,26 @@ #define SGX_CPUID_EPC_SECTION 0x1 /* The bitmask for the EPC section type. */ #define SGX_CPUID_EPC_MASK GENMASK(3, 0) +/* EUPDATESVN presence indication */ +#define SGX_CPUID_EUPDATESVN BIT(10) enum sgx_encls_function { - ECREATE = 0x00, - EADD = 0x01, - EINIT = 0x02, - EREMOVE = 0x03, - EDGBRD = 0x04, - EDGBWR = 0x05, - EEXTEND = 0x06, - ELDU = 0x08, - EBLOCK = 0x09, - EPA = 0x0A, - EWB = 0x0B, - ETRACK = 0x0C, - EAUG = 0x0D, - EMODPR = 0x0E, - EMODT = 0x0F, + ECREATE = 0x00, + EADD = 0x01, + EINIT = 0x02, + EREMOVE = 0x03, + EDGBRD = 0x04, + EDGBWR = 0x05, + EEXTEND = 0x06, + ELDU = 0x08, + EBLOCK = 0x09, + EPA = 0x0A, + EWB = 0x0B, + ETRACK = 0x0C, + EAUG = 0x0D, + EMODPR = 0x0E, + EMODT = 0x0F, + EUPDATESVN = 0x18, }; /** diff --git a/arch/x86/kernel/cpu/sgx/encls.h b/arch/x86/kernel/cpu/sgx/encls.h index 60321c5f5718..8455f385e817 100644 --- a/arch/x86/kernel/cpu/sgx/encls.h +++ b/arch/x86/kernel/cpu/sgx/encls.h @@ -208,4 +208,10 @@ static inline int __ewb(struct sgx_pageinfo *pginfo, void *addr, return __encls_ret_3(EWB, pginfo, addr, va); } +/* Update CPUSVN at runtime. */ +static inline int __eupdatesvn(void) +{ + return __encls_ret_1(EUPDATESVN, ""); +} + #endif /* _X86_ENCLS_H */ diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index fbfa449d90ed..43dd2b34e040 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -1351,3 +1351,55 @@ void sgx_zap_abort(void) sgx_zap_abort_wait = true; wake_up(&sgx_zap_waitq); } + +/** + * sgx_updatesvn() - Issue ENCLS[EUPDATESVN] + * If EPC is ready, this instruction will update CPUSVN to the currently + * loaded microcode update SVN and generate new cryptographic assets. + * + * Return: + * 0: CPUSVN is update successfully. + * %SGX_LOCKFAIL: An instruction concurrency rule was violated. + * %SGX_INSUFFICIENT_ENTROPY: Insufficient entropy in RNG. + * %SGX_EPC_NOT_READY: EPC is not ready for SVN update. + * %SGX_NO_UPDATE: EUPDATESVN was successful, but CPUSVN was not + * updated because current SVN was not newer than + * CPUSVN. + */ +static int sgx_updatesvn(void) +{ + int ret; + int retry = 10; + + do { + ret = __eupdatesvn(); + if (ret != SGX_INSUFFICIENT_ENTROPY) + break; + + } while (--retry); + + switch (ret) { + case 0: + pr_info("EUPDATESVN was successful!\n"); + break; + case SGX_NO_UPDATE: + pr_info("EUPDATESVN was successful, but CPUSVN was not updated, " + "because current SVN was not newer than CPUSVN.\n"); + break; + case SGX_EPC_NOT_READY: + pr_info("EPC is not ready for SVN update."); + break; + case SGX_INSUFFICIENT_ENTROPY: + pr_info("CPUSVN update is failed due to Insufficient entropy in RNG, " + "please try it later.\n"); + break; + case SGX_EPC_PAGE_CONFLICT: + pr_info("CPUSVN update is failed due to concurrency violation, please " + "stop running any other ENCLS leaf and try it later.\n"); + break; + default: + break; + } + + return ret; +}