From patchwork Sun Mar 15 05:05:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xiaoyao Li X-Patchwork-Id: 11438719 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 2EE9E913 for ; Sun, 15 Mar 2020 05:23:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1956A20738 for ; Sun, 15 Mar 2020 05:23:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727832AbgCOFXh (ORCPT ); Sun, 15 Mar 2020 01:23:37 -0400 Received: from mga18.intel.com ([134.134.136.126]:47872 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727508AbgCOFXH (ORCPT ); Sun, 15 Mar 2020 01:23:07 -0400 IronPort-SDR: cd0F+eMp9X0FZjcuS3/acIRjGxIp8iwjSuzhtGZTzFtQHelJVzIY1d6boeR7mlglDbyQ/AQP0e aKdRwMUzuQcA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Mar 2020 22:23:06 -0700 IronPort-SDR: Y5oYakOTTQYy7ktg+i6GwXDd7ztj2Y16YpdZ7Gd/UjtW27FgooCQ7f73s7TJkNUO2eL0+6A2OW um1I3eCxHFrw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,555,1574150400"; d="scan'208";a="267194241" Received: from lxy-clx-4s.sh.intel.com ([10.239.43.160]) by fmsmga004.fm.intel.com with ESMTP; 14 Mar 2020 22:23:02 -0700 From: Xiaoyao Li To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , hpa@zytor.com, Paolo Bonzini , Sean Christopherson , kvm@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org Cc: Andy Lutomirski , Peter Zijlstra , Arvind Sankar , Fenghua Yu , Tony Luck , Vitaly Kuznetsov , Jim Mattson , Xiaoyao Li Subject: [PATCH v5 4/9] x86/split_lock: Export handle_user_split_lock() Date: Sun, 15 Mar 2020 13:05:12 +0800 Message-Id: <20200315050517.127446-5-xiaoyao.li@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200315050517.127446-1-xiaoyao.li@intel.com> References: <20200315050517.127446-1-xiaoyao.li@intel.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org 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 EFLASG.AC, move the EFLAGS.AC check to do_alignment_check(). Suggested-by: Sean Christopherson Signed-off-by: Xiaoyao Li Reviewed-by: Tony Luck --- 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 3eeab717a0d0..c401d174c8db 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -1102,13 +1102,13 @@ static void split_lock_init(struct cpuinfo_x86 *c) sld_state = sld_disable; } -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 @@ -1119,6 +1119,7 @@ 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 0ef5befaed7d..407ff9be610f 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,