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=-8.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 0D124C04AAB for ; Wed, 8 May 2019 14:51:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DDDF020989 for ; Wed, 8 May 2019 14:51:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728769AbfEHOvL (ORCPT ); Wed, 8 May 2019 10:51:11 -0400 Received: from mga02.intel.com ([134.134.136.20]:19899 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728136AbfEHOon (ORCPT ); Wed, 8 May 2019 10:44:43 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 May 2019 07:44:43 -0700 X-ExtLoop1: 1 Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga001.fm.intel.com with ESMTP; 08 May 2019 07:44:39 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id 74047949; Wed, 8 May 2019 17:44:29 +0300 (EEST) From: "Kirill A. Shutemov" To: Andrew Morton , x86@kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Borislav Petkov , Peter Zijlstra , Andy Lutomirski , David Howells Cc: Kees Cook , Dave Hansen , Kai Huang , Jacob Pan , Alison Schofield , linux-mm@kvack.org, kvm@vger.kernel.org, keyrings@vger.kernel.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCH, RFC 16/62] x86/mm: Allow to disable MKTME after enumeration Date: Wed, 8 May 2019 17:43:36 +0300 Message-Id: <20190508144422.13171-17-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190508144422.13171-1-kirill.shutemov@linux.intel.com> References: <20190508144422.13171-1-kirill.shutemov@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 The new helper mktme_disable() allows to disable MKTME even if it's enumerated successfully. MKTME initialization may fail and this functionality allows system to boot regardless of the failure. MKTME needs per-KeyID direct mapping. It requires a lot more virtual address space which may be a problem in 4-level paging mode. If the system has more physical memory than we can handle with MKTME the feature allows to fail MKTME, but boot the system successfully. Signed-off-by: Kirill A. Shutemov --- arch/x86/include/asm/mktme.h | 5 +++++ arch/x86/kernel/cpu/intel.c | 5 +---- arch/x86/mm/mktme.c | 10 ++++++++++ 3 files changed, 16 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/mktme.h b/arch/x86/include/asm/mktme.h index 6e604126f0bc..454d6d7c791d 100644 --- a/arch/x86/include/asm/mktme.h +++ b/arch/x86/include/asm/mktme.h @@ -18,6 +18,8 @@ static inline bool mktme_enabled(void) return static_branch_unlikely(&mktme_enabled_key); } +void mktme_disable(void); + extern struct page_ext_operations page_mktme_ops; #define page_keyid page_keyid @@ -68,6 +70,9 @@ static inline bool mktme_enabled(void) { return false; } + +static inline void mktme_disable(void) {} + #endif #endif diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 4c9fadb57a13..f402a74c00a1 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -618,10 +618,7 @@ static void detect_tme(struct cpuinfo_x86 *c) * We must not allow onlining secondary CPUs with non-matching * configuration. */ - physical_mask = (1ULL << __PHYSICAL_MASK_SHIFT) - 1; - mktme_keyid_mask = 0; - mktme_keyid_shift = 0; - mktme_nr_keyids = 0; + mktme_disable(); } #endif diff --git a/arch/x86/mm/mktme.c b/arch/x86/mm/mktme.c index 43489c098e60..9221c894e8e9 100644 --- a/arch/x86/mm/mktme.c +++ b/arch/x86/mm/mktme.c @@ -15,6 +15,16 @@ int mktme_keyid_shift; DEFINE_STATIC_KEY_FALSE(mktme_enabled_key); EXPORT_SYMBOL_GPL(mktme_enabled_key); +void mktme_disable(void) +{ + physical_mask = (1ULL << __PHYSICAL_MASK_SHIFT) - 1; + mktme_keyid_mask = 0; + mktme_keyid_shift = 0; + mktme_nr_keyids = 0; + if (mktme_enabled()) + static_branch_disable(&mktme_enabled_key); +} + static bool need_page_mktme(void) { /* Make sure keyid doesn't collide with extended page flags */ -- 2.20.1