From patchwork Sat May 9 11:05:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xiaoyao Li X-Patchwork-Id: 11537919 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C5D73139F for ; Sat, 9 May 2020 03:04:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B91E4218AC for ; Sat, 9 May 2020 03:04:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728737AbgEIDDx (ORCPT ); Fri, 8 May 2020 23:03:53 -0400 Received: from mga12.intel.com ([192.55.52.136]:55091 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728752AbgEIDDw (ORCPT ); Fri, 8 May 2020 23:03:52 -0400 IronPort-SDR: zL+JbQmzfdTfKk8nn3Ddi3jL6g9MXXYeVvnQbPQpr47Icd6XmYI0Ip5CziBlIA24iYJRpZGGmZ KJ7hoTfNFxTA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 May 2020 20:03:48 -0700 IronPort-SDR: 8OhJwXpbyoeBle1+jQMFkSwIHy6Qoo5RYA1KJuUli6gd+rwJQNqP2nglitEJHCVI0wXGjDiCOf BaWfbn/wzMcA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,370,1583222400"; d="scan'208";a="408311046" Received: from lxy-dell.sh.intel.com ([10.239.159.21]) by orsmga004.jf.intel.com with ESMTP; 08 May 2020 20:03:44 -0700 From: Xiaoyao Li To: Paolo Bonzini , Thomas Gleixner , Sean Christopherson , kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, x86@kernel.org, Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Andy Lutomirski , peterz@infradead.org, Arvind Sankar , Tony Luck , Fenghua Yu , Xiaoyao Li Subject: [PATCH v9 3/8] x86/split_lock: Introduce flag X86_FEATURE_SLD_FATAL and drop sld_state Date: Sat, 9 May 2020 19:05:37 +0800 Message-Id: <20200509110542.8159-4-xiaoyao.li@intel.com> X-Mailer: git-send-email 2.18.2 In-Reply-To: <20200509110542.8159-1-xiaoyao.li@intel.com> References: <20200509110542.8159-1-xiaoyao.li@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Introduce a synthetic feature flag X86_FEATURE_SLD_FATAL, which means kernel is in sld_fatal mode if set. Now sld_state is not needed any more that the state of SLD can be inferred from X86_FEATURE_SPLIT_LOCK_DETECT and X86_FEATURE_SLD_FATAL. Suggested-by: Sean Christopherson Signed-off-by: Xiaoyao Li --- arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/kernel/cpu/intel.c | 16 ++++++---------- 2 files changed, 7 insertions(+), 10 deletions(-) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index db189945e9b0..260adfc6c61a 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -286,6 +286,7 @@ #define X86_FEATURE_FENCE_SWAPGS_USER (11*32+ 4) /* "" LFENCE in user entry SWAPGS path */ #define X86_FEATURE_FENCE_SWAPGS_KERNEL (11*32+ 5) /* "" LFENCE in kernel entry SWAPGS path */ #define X86_FEATURE_SPLIT_LOCK_DETECT (11*32+ 6) /* #AC for split lock */ +#define X86_FEATURE_SLD_FATAL (11*32+ 7) /* split lock detection in fatal mode */ /* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */ #define X86_FEATURE_AVX512_BF16 (12*32+ 5) /* AVX512 BFLOAT16 instructions */ diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 4602dac14dcb..93b8ccf2fa11 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -40,12 +40,6 @@ enum split_lock_detect_state { sld_fatal, }; -/* - * Default to sld_off because most systems do not support split lock detection - * split_lock_setup() will switch this to sld_warn on systems that support - * split lock detect, unless there is a command line override. - */ -static enum split_lock_detect_state sld_state __ro_after_init = sld_off; static u64 msr_test_ctrl_cache __ro_after_init; /* @@ -1043,8 +1037,9 @@ static void __init split_lock_setup(void) return; } - sld_state = state; setup_force_cpu_cap(X86_FEATURE_SPLIT_LOCK_DETECT); + if (state == sld_fatal) + setup_force_cpu_cap(X86_FEATURE_SLD_FATAL); } /* @@ -1064,7 +1059,7 @@ static void sld_update_msr(bool on) static void split_lock_init(void) { - split_lock_verify_msr(sld_state != sld_off); + split_lock_verify_msr(boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)); } static void split_lock_warn(unsigned long ip) @@ -1083,7 +1078,7 @@ static void split_lock_warn(unsigned long ip) bool handle_guest_split_lock(unsigned long ip) { - if (sld_state == sld_warn) { + if (!boot_cpu_has(X86_FEATURE_SLD_FATAL)) { split_lock_warn(ip); return true; } @@ -1100,7 +1095,8 @@ EXPORT_SYMBOL_GPL(handle_guest_split_lock); bool handle_user_split_lock(struct pt_regs *regs, long error_code) { - if ((regs->flags & X86_EFLAGS_AC) || sld_state == sld_fatal) + if ((regs->flags & X86_EFLAGS_AC) || + boot_cpu_has(X86_FEATURE_SLD_FATAL)) return false; split_lock_warn(regs->ip); return true;