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 ADB70C43331 for ; Thu, 2 Apr 2020 15:57:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8CF7520757 for ; Thu, 2 Apr 2020 15:57:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389693AbgDBP5D (ORCPT ); Thu, 2 Apr 2020 11:57:03 -0400 Received: from mga06.intel.com ([134.134.136.31]:50591 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389318AbgDBP4u (ORCPT ); Thu, 2 Apr 2020 11:56:50 -0400 IronPort-SDR: YfTEspLrUd9NC6Y5bg0S6asn26YdGedv+WaFPQPTI5YW2FFP75kA3l6iWiNGeN/qhc081Y6ckr l/+pXrycsejA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Apr 2020 08:56:49 -0700 IronPort-SDR: hOmnY10zsClqRvcXjfjp1LY7mswTggcs1bi9KCHgPjwwUa+iuvtVhFNa1fsTtWR6WUvHFiUNKF UBNwd/7pGtcw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,336,1580803200"; d="scan'208";a="396413085" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.202]) by orsmga004.jf.intel.com with ESMTP; 02 Apr 2020 08:56:49 -0700 From: Sean Christopherson To: Thomas Gleixner Cc: x86@kernel.org, "Kenneth R . Crudup" , Paolo Bonzini , Fenghua Yu , Xiaoyao Li , Nadav Amit , Thomas Hellstrom , Sean Christopherson , Tony Luck , Peter Zijlstra , Jessica Yu , Steven Rostedt , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/3] x86/split_lock: Refactor and export handle_user_split_lock() for KVM Date: Thu, 2 Apr 2020 08:55:53 -0700 Message-Id: <20200402155554.27705-3-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200402155554.27705-1-sean.j.christopherson@intel.com> References: <20200402124205.334622628@linutronix.de> <20200402155554.27705-1-sean.j.christopherson@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: Xiaoyao Li In the future, KVM will use handle_user_split_lock() to handle #AC caused by split lock in guest. Due to the fact that KVM doesn't have a @regs context and will pre-check EFLAGS.AC, move the EFLAGS.AC check to do_alignment_check(). Suggested-by: Sean Christopherson Signed-off-by: Xiaoyao Li Reviewed-by: Tony Luck Signed-off-by: Sean Christopherson --- arch/x86/include/asm/cpu.h | 4 ++-- arch/x86/kernel/cpu/intel.c | 7 ++++--- arch/x86/kernel/traps.c | 2 +- 3 files changed, 7 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index ff6f3ca649b3..ff567afa6ee1 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -43,11 +43,11 @@ unsigned int x86_stepping(unsigned int sig); #ifdef CONFIG_CPU_SUP_INTEL extern void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c); extern void switch_to_sld(unsigned long tifn); -extern bool handle_user_split_lock(struct pt_regs *regs, long error_code); +extern bool handle_user_split_lock(unsigned long ip); #else static inline void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c) {} static inline void switch_to_sld(unsigned long tifn) {} -static inline bool handle_user_split_lock(struct pt_regs *regs, long error_code) +static inline bool handle_user_split_lock(unsigned long ip) { return false; } diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 9a26e972cdea..7688f51aabdb 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -1066,13 +1066,13 @@ static void split_lock_init(void) split_lock_verify_msr(sld_state != sld_off); } -bool handle_user_split_lock(struct pt_regs *regs, long error_code) +bool handle_user_split_lock(unsigned long ip) { - if ((regs->flags & X86_EFLAGS_AC) || sld_state == sld_fatal) + if (sld_state == sld_fatal) return false; pr_warn_ratelimited("#AC: %s/%d took a split_lock trap at address: 0x%lx\n", - current->comm, current->pid, regs->ip); + current->comm, current->pid, ip); /* * Disable the split lock detection for this task so it can make @@ -1083,6 +1083,7 @@ bool handle_user_split_lock(struct pt_regs *regs, long error_code) set_tsk_thread_flag(current, TIF_SLD); return true; } +EXPORT_SYMBOL_GPL(handle_user_split_lock); /* * This function is called only when switching between tasks with diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index d54cffdc7cac..55902c5bf0aa 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -304,7 +304,7 @@ dotraplinkage void do_alignment_check(struct pt_regs *regs, long error_code) local_irq_enable(); - if (handle_user_split_lock(regs, error_code)) + if (!(regs->flags & X86_EFLAGS_AC) && handle_user_split_lock(regs->ip)) return; do_trap(X86_TRAP_AC, SIGBUS, "alignment check", regs, -- 2.24.1