From patchwork Fri Dec 21 23:11:37 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 10741099 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A503A13B5 for ; Fri, 21 Dec 2018 23:13:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 956AD28538 for ; Fri, 21 Dec 2018 23:13:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 88B9F28618; Fri, 21 Dec 2018 23:13:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6C48928538 for ; Fri, 21 Dec 2018 23:13:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388956AbeLUXNX (ORCPT ); Fri, 21 Dec 2018 18:13:23 -0500 Received: from mga09.intel.com ([134.134.136.24]:16734 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389005AbeLUXNU (ORCPT ); Fri, 21 Dec 2018 18:13:20 -0500 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; 21 Dec 2018 15:13:19 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,383,1539673200"; d="scan'208";a="120338331" Received: from ncanderx-mobl.ger.corp.intel.com (HELO localhost) ([10.249.254.238]) by FMSMGA003.fm.intel.com with ESMTP; 21 Dec 2018 15:13:13 -0800 From: Jarkko Sakkinen To: 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, Jarkko Sakkinen Subject: [PATCH v18 08/25] x86/cpu/intel: Detect SGX support and update caps appropriately Date: Sat, 22 Dec 2018 01:11:37 +0200 Message-Id: <20181221231154.6120-9-jarkko.sakkinen@linux.intel.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181221231154.6120-1-jarkko.sakkinen@linux.intel.com> References: <20181221231154.6120-1-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Sean Christopherson Similar to other large Intel features such as VMX and TXT, SGX must be explicitly enabled in IA32_FEATURE_CONTROL MSR to be truly usable. Clear all SGX related capabilities if SGX is not fully enabled in IA32_FEATURE_CONTROL or if the SGX1 instruction set isn't supported (impossible on bare metal, theoretically possible in a VM if the VMM is doing something weird). Like SGX itself, SGX Launch Control must be explicitly enabled via a flag in IA32_FEATURE_CONTROL. Clear the SGX_LC capability if Launch Control is not fully enabled (or obviously if SGX itself is disabled). Note that clearing X86_FEATURE_SGX_LC creates a bit of a conundrum regarding the SGXLEPUBKEYHASH MSRs, as it may be desirable to read the MSRs even if they are not writable, e.g. to query the configured key, but clearing the capability leaves no breadcrum for discerning whether or not the MSRs exist. But, such usage will be rare (KVM is the only known case at this time) and not performance critical, so it's not unreasonable to require the use of rdmsr_safe(). Clearing the cap bit eliminates the need for an additional flag to track whether or not Launch Control is truly enabled, which is what we care about the vast majority of the time. Signed-off-by: Sean Christopherson Co-developed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- arch/x86/kernel/cpu/intel.c | 39 +++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index fc3c07fe7df5..19ac424b6591 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -596,6 +596,42 @@ static void detect_tme(struct cpuinfo_x86 *c) c->x86_phys_bits -= keyid_bits; } +static void __maybe_unused detect_sgx(struct cpuinfo_x86 *c) +{ + unsigned long long fc; + + rdmsrl(MSR_IA32_FEATURE_CONTROL, fc); + if (!(fc & FEATURE_CONTROL_LOCKED)) { + pr_err_once("sgx: The feature control MSR is not locked\n"); + goto err_unsupported; + } + + if (!(fc & FEATURE_CONTROL_SGX_ENABLE)) { + pr_err_once("sgx: SGX is not enabled in IA32_FEATURE_CONTROL MSR\n"); + goto err_unsupported; + } + + if (!cpu_has(c, X86_FEATURE_SGX1)) { + pr_err_once("sgx: SGX1 instruction set is not supported\n"); + goto err_unsupported; + } + + if (!(fc & FEATURE_CONTROL_SGX_LE_WR)) { + pr_info_once("sgx: The launch control MSRs are not writable\n"); + goto err_msrs_rdonly; + } + + return; + +err_unsupported: + setup_clear_cpu_cap(X86_FEATURE_SGX); + setup_clear_cpu_cap(X86_FEATURE_SGX1); + setup_clear_cpu_cap(X86_FEATURE_SGX2); + +err_msrs_rdonly: + setup_clear_cpu_cap(X86_FEATURE_SGX_LC); +} + static void init_intel_energy_perf(struct cpuinfo_x86 *c) { u64 epb; @@ -763,6 +799,9 @@ static void init_intel(struct cpuinfo_x86 *c) if (cpu_has(c, X86_FEATURE_TME)) detect_tme(c); + if (IS_ENABLED(CONFIG_SGX) && cpu_has(c, X86_FEATURE_SGX)) + detect_sgx(c); + init_intel_energy_perf(c); init_intel_misc_features(c);