From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 576A3C3A5A2 for ; Tue, 3 Sep 2019 14:28:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3B3BF23431 for ; Tue, 3 Sep 2019 14:28:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729631AbfICO2f (ORCPT ); Tue, 3 Sep 2019 10:28:35 -0400 Received: from mga09.intel.com ([134.134.136.24]:34192 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729701AbfICO2d (ORCPT ); Tue, 3 Sep 2019 10:28:33 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Sep 2019 07:28:32 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,463,1559545200"; d="scan'208";a="189825963" Received: from vkuppusa-mobl2.ger.corp.intel.com (HELO localhost) ([10.252.39.67]) by FMSMGA003.fm.intel.com with ESMTP; 03 Sep 2019 07:28:26 -0700 From: Jarkko Sakkinen To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: akpm@linux-foundation.org, dave.hansen@intel.com, sean.j.christopherson@intel.com, nhorman@redhat.com, npmccallum@redhat.com, serge.ayoun@intel.com, shay.katz-zamir@intel.com, haitao.huang@intel.com, andriy.shevchenko@linux.intel.com, tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com, rientjes@google.com, cedric.xing@intel.com, Jarkko Sakkinen Subject: [PATCH v22 10/24] x86/sgx: Add sgx_einit() for wrapping ENCLS[EINIT] Date: Tue, 3 Sep 2019 17:26:41 +0300 Message-Id: <20190903142655.21943-11-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190903142655.21943-1-jarkko.sakkinen@linux.intel.com> References: <20190903142655.21943-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sean Christopherson Enclaves are SGX hosted measured and signed software entities. ENCLS[EINIT] leaf function checks that the enclave has a legit signed measurement and transforms the enclave to the state ready for execution. The signed measurement is provided by the caller in the form of SIGSTRUCT data structure [1]. Wrap ENCLS[EINIT] into sgx_einit(). Set MSR_IA32_SGXLEPUBKEYHASH* MSRs to match the public key contained in the SIGSTRUCT [2]. This sets Linux to enforce a policy where the provided public key is as long as the signed measurement matches the enclave contents in memory. Add a per-cpu cache to avoid unnecessary reads and write to the MSRs as they are expensive operations. [1] Intel SDM: 37.1.3 ENCLAVE SIGNATURE STRUCTURE (SIGSTRUCT) [2] Intel SDM: 38.1.4 Intel SGX Launch Control Configuration Signed-off-by: Sean Christopherson Co-developed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- arch/x86/kernel/cpu/sgx/main.c | 51 ++++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/sgx/sgx.h | 2 ++ 2 files changed, 53 insertions(+) diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index 6b4727df72ca..d3ed742e90fe 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c @@ -17,6 +17,9 @@ EXPORT_SYMBOL_GPL(sgx_epc_sections); int sgx_nr_epc_sections; +/* A per-cpu cache for the last known values of IA32_SGXLEPUBKEYHASHx MSRs. */ +static DEFINE_PER_CPU(u64 [4], sgx_lepubkeyhash_cache); + static struct sgx_epc_page *sgx_section_get_page( struct sgx_epc_section *section) { @@ -106,6 +109,54 @@ void sgx_free_page(struct sgx_epc_page *page) } EXPORT_SYMBOL_GPL(sgx_free_page); +static void sgx_update_lepubkeyhash_msrs(u64 *lepubkeyhash, bool enforce) +{ + u64 *cache; + int i; + + cache = per_cpu(sgx_lepubkeyhash_cache, smp_processor_id()); + for (i = 0; i < 4; i++) { + if (enforce || (lepubkeyhash[i] != cache[i])) { + wrmsrl(MSR_IA32_SGXLEPUBKEYHASH0 + i, lepubkeyhash[i]); + cache[i] = lepubkeyhash[i]; + } + } +} + +/** + * sgx_einit - initialize an enclave + * @sigstruct: a pointer a SIGSTRUCT + * @token: a pointer an EINITTOKEN (optional) + * @secs: a pointer a SECS + * @lepubkeyhash: the desired value for IA32_SGXLEPUBKEYHASHx MSRs + * + * Execute ENCLS[EINIT], writing the IA32_SGXLEPUBKEYHASHx MSRs according + * to @lepubkeyhash (if possible and necessary). + * + * Return: + * 0 on success, + * -errno or SGX error on failure + */ +int sgx_einit(struct sgx_sigstruct *sigstruct, struct sgx_einittoken *token, + struct sgx_epc_page *secs, u64 *lepubkeyhash) +{ + int ret; + + if (!boot_cpu_has(X86_FEATURE_SGX_LC)) + return __einit(sigstruct, token, sgx_epc_addr(secs)); + + preempt_disable(); + sgx_update_lepubkeyhash_msrs(lepubkeyhash, false); + ret = __einit(sigstruct, token, sgx_epc_addr(secs)); + if (ret == SGX_INVALID_EINITTOKEN) { + sgx_update_lepubkeyhash_msrs(lepubkeyhash, true); + ret = __einit(sigstruct, token, sgx_epc_addr(secs)); + } + preempt_enable(); + return ret; +} +EXPORT_SYMBOL(sgx_einit); + static __init void sgx_free_epc_section(struct sgx_epc_section *section) { struct sgx_epc_page *page; diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index 210510a28ce0..41d4130c33a2 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h @@ -67,5 +67,7 @@ int sgx_page_reclaimer_init(void); struct sgx_epc_page *sgx_alloc_page(void); int __sgx_free_page(struct sgx_epc_page *page); void sgx_free_page(struct sgx_epc_page *page); +int sgx_einit(struct sgx_sigstruct *sigstruct, struct sgx_einittoken *token, + struct sgx_epc_page *secs, u64 *lepubkeyhash); #endif /* _X86_SGX_H */ -- 2.20.1