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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 275F7C433F5 for ; Tue, 5 Oct 2021 23:06:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0FF916117A for ; Tue, 5 Oct 2021 23:06:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237038AbhJEXIb (ORCPT ); Tue, 5 Oct 2021 19:08:31 -0400 Received: from mga12.intel.com ([192.55.52.136]:14170 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237007AbhJEXIL (ORCPT ); Tue, 5 Oct 2021 19:08:11 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10128"; a="205998550" X-IronPort-AV: E=Sophos;i="5.85,350,1624345200"; d="scan'208";a="205998550" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Oct 2021 16:06:20 -0700 X-IronPort-AV: E=Sophos;i="5.85,350,1624345200"; d="scan'208";a="438908098" Received: from alyee-mobl.amr.corp.intel.com (HELO skuppusw-desk1.amr.corp.intel.com) ([10.254.5.222]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Oct 2021 16:06:18 -0700 From: Kuppuswamy Sathyanarayanan To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, Paolo Bonzini , David Hildenbrand , Andrea Arcangeli , Josh Poimboeuf , "H . Peter Anvin" Cc: Dave Hansen , Tony Luck , Dan Williams , Andi Kleen , Kirill Shutemov , Sean Christopherson , Kuppuswamy Sathyanarayanan , Kuppuswamy Sathyanarayanan , linux-kernel@vger.kernel.org Subject: [PATCH v7 6/6] x86/split_lock: Fix the split lock #AC handling when running as guest Date: Tue, 5 Oct 2021 16:05:50 -0700 Message-Id: <20211005230550.1819406-7-sathyanarayanan.kuppuswamy@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211005230550.1819406-1-sathyanarayanan.kuppuswamy@linux.intel.com> References: <20211005230550.1819406-1-sathyanarayanan.kuppuswamy@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xiaoyao Li If running as guest and hypervisor enables MSR_TEST_CTRL.SPLIT_LOCK_DETECT during its running, it can get split lock #AC even though sld_state is sld_off. For kernel mode #AC, it always dies("split lock"), no more action needed. For user mode #AC, it should treat sld_off (default state when feature is not available) as fatal as well. Signed-off-by: Xiaoyao Li Signed-off-by: Kuppuswamy Sathyanarayanan --- arch/x86/kernel/cpu/intel.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 01d7935feaed..47f0bc95ce2a 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -1190,7 +1190,12 @@ static void bus_lock_init(void) bool handle_user_split_lock(struct pt_regs *regs, long error_code) { - if ((regs->flags & X86_EFLAGS_AC) || sld_state == sld_fatal) + /* + * In virtualization environment, it can get split lock #AC even when + * sld_off but hypervisor enables it. + * Thus only handles when sld_warn explicitly. + */ + if ((regs->flags & X86_EFLAGS_AC) || sld_state != sld_warn) return false; split_lock_warn(regs->ip); return true; -- 2.25.1