From patchwork Tue Mar 15 01:02:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Zhang, Cathy" X-Patchwork-Id: 12780919 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 B2372C4332F for ; Tue, 15 Mar 2022 01:02:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344119AbiCOBEG (ORCPT ); Mon, 14 Mar 2022 21:04:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38556 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344111AbiCOBEC (ORCPT ); Mon, 14 Mar 2022 21:04:02 -0400 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 01998630B; Mon, 14 Mar 2022 18:02:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1647306171; x=1678842171; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=Tj2I3escwpqO37YCAmvWnobN+FzpJ6eNFMd9Lxv7zvQ=; b=DaIGWecACI42vLD0RPPFJXlgOf6d1PQiSjdfj9yEinKDavCEYlApx8hx /A6cUbprCHjbc0eA/0vfRk378HD0Qt7eV7NxETBiO+sU6PCp8b1DI54NF aOh0qsArneaSonu0B5Gl+ww/AYr0KIKQMdbMZGPcXbiSUOpz71YF8/m0c rNZv/maEyUXYW5zgsb7qEFt4/6xfueTseDIq80+h9zCzIFj/GsEqj+EBh mOAUadbw72eLLK/NtFANLVgdLGsDOJx3wI7a3Lt3aWVentnls9YjSk+aW AR3ghejspcHZwbl/S5+gMg26ztANmd5+CDR5pEZW7zxbjkgLh0Ah7h6V3 g==; X-IronPort-AV: E=McAfee;i="6200,9189,10286"; a="255912374" X-IronPort-AV: E=Sophos;i="5.90,181,1643702400"; d="scan'208";a="255912374" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Mar 2022 18:02:50 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,181,1643702400"; d="scan'208";a="515669364" Received: from cathy-vostro-3670.bj.intel.com ([10.238.156.128]) by orsmga006.jf.intel.com with ESMTP; 14 Mar 2022 18:02:49 -0700 From: Cathy Zhang To: linux-sgx@vger.kernel.org, linux-kernel@vger.kernel.org Cc: dave.hansen@intel.com, ashok.raj@intel.com, cathy.zhang@intel.com Subject: [RFC PATCH v2 08/10] x86/sgx: Implement ENCLS[EUPDATESVN] Date: Tue, 15 Mar 2022 09:02:58 +0800 Message-Id: <20220315010300.10199-9-cathy.zhang@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220315010300.10199-1-cathy.zhang@intel.com> References: <20220315010300.10199-1-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 6aa36c1be426..d5942d0848ec 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 3f1797ec2445..b0aa110e7560 100644 --- a/arch/x86/kernel/cpu/sgx/encls.h +++ b/arch/x86/kernel/cpu/sgx/encls.h @@ -243,4 +243,10 @@ static inline int __eaug(struct sgx_pageinfo *pginfo, void *addr) return __encls_2(EAUG, pginfo, addr); } +/* 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 f3dd3757ef9f..123818fa2386 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -1328,3 +1328,55 @@ 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; +}