From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753198AbaEZRDc (ORCPT ); Mon, 26 May 2014 13:03:32 -0400 Received: from mga01.intel.com ([192.55.52.88]:43464 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751524AbaEZQ5u (ORCPT ); Mon, 26 May 2014 12:57:50 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.98,914,1392192000"; d="scan'208";a="545122311" From: "Fenghua Yu" To: "H. Peter Anvin" , "Ingo Molnar" , "Thomas Gleixner" , "Asit K Mallick" Cc: "linux-kernel" , "x86" , "Fenghua Yu" Subject: [PATCH 02/15] x86/xsaves: Add kernel parameter to disable xsaves/xrstors Date: Mon, 26 May 2014 10:01:09 -0700 Message-Id: <1401123682-5384-3-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 1.8.0.1 In-Reply-To: <1401123682-5384-1-git-send-email-fenghua.yu@intel.com> References: <1401123682-5384-1-git-send-email-fenghua.yu@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Fenghua Yu Add kernel parameter noxsaves to disable xsaves/xrstors feature. Add kernel parameter noxsaveopt in doc. Signed-off-by: Fenghua Yu --- Documentation/kernel-parameters.txt | 9 +++++++++ arch/x86/kernel/cpu/common.c | 8 ++++++++ 2 files changed, 17 insertions(+) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 4384217..8541752 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2124,6 +2124,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted. and restore using xsave. The kernel will fallback to enabling legacy floating-point and sse state. + noxsaveopt [X86] Disables x86 extended register state context + switch using xsaveopt. The kernel wil fallback to use + not optimized xsave to do context switch. + + noxsaves [X86] Disables x86 extended register state context + switch and save/restore compacted formated xsave + area using xsaves. Then the kernel uses standard + xsave area for xstate. + eagerfpu= [X86] on enable eager fpu restore off disable eager fpu restore diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index a135239..409f47c 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -146,6 +146,7 @@ static int __init x86_xsave_setup(char *s) { setup_clear_cpu_cap(X86_FEATURE_XSAVE); setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT); + setup_clear_cpu_cap(X86_FEATURE_XSAVES); setup_clear_cpu_cap(X86_FEATURE_AVX); setup_clear_cpu_cap(X86_FEATURE_AVX2); return 1; @@ -159,6 +160,13 @@ static int __init x86_xsaveopt_setup(char *s) } __setup("noxsaveopt", x86_xsaveopt_setup); +static int __init x86_xsaves_setup(char *s) +{ + setup_clear_cpu_cap(X86_FEATURE_XSAVES); + return 1; +} +__setup("noxsaves", x86_xsaves_setup); + #ifdef CONFIG_X86_32 static int cachesize_override = -1; static int disable_x86_serial_nr = 1; -- 1.8.1.2