From patchwork Tue Mar 12 23:00:33 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 10850155 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D21711515 for ; Tue, 12 Mar 2019 23:09:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C251929575 for ; Tue, 12 Mar 2019 23:09:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B5B37295FA; Tue, 12 Mar 2019 23:09:59 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6325C29575 for ; Tue, 12 Mar 2019 23:09:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727502AbfCLXJu (ORCPT ); Tue, 12 Mar 2019 19:09:50 -0400 Received: from mga18.intel.com ([134.134.136.126]:65104 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727357AbfCLXIR (ORCPT ); Tue, 12 Mar 2019 19:08:17 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Mar 2019 16:08:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,472,1544515200"; d="scan'208";a="326744259" Received: from romley-ivt3.sc.intel.com ([172.25.110.60]) by fmsmga006.fm.intel.com with ESMTP; 12 Mar 2019 16:08:14 -0700 From: Fenghua Yu To: "Thomas Gleixner" , "Ingo Molnar" , "H Peter Anvin" , "Dave Hansen" , "Paolo Bonzini" , "Ashok Raj" , "Peter Zijlstra" , "Xiaoyao Li " , "Michael Chan" , "Ravi V Shankar" Cc: "linux-kernel" , "x86" , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, Fenghua Yu Subject: [PATCH v5 15/18] x86/clearcpuid: Support feature flag string in kernel option clearcpuid Date: Tue, 12 Mar 2019 16:00:33 -0700 Message-Id: <1552431636-31511-16-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1552431636-31511-1-git-send-email-fenghua.yu@intel.com> References: <1552431636-31511-1-git-send-email-fenghua.yu@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The kernel option clearcpuid currently only takes feature bit which can be changed from kernel to kernel. Extend clearcpuid to use cap flag string, which is defined in x86_cap_flags[] and won't be changed from kernel to kernel. And user can easily get the cap flag string from /proc/cpuinfo. Signed-off-by: Fenghua Yu --- arch/x86/include/asm/cpufeature.h | 1 + arch/x86/kernel/cpu/cpuid-deps.c | 26 ++++++++++++++++++++++++++ arch/x86/kernel/fpu/init.c | 3 ++- 3 files changed, 29 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index ce95b8cbd229..6792088525e3 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -132,6 +132,7 @@ extern const char * const x86_bug_flags[NBUGINTS*32]; extern void setup_clear_cpu_cap(unsigned int bit); extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit); +bool find_cpu_cap(char *cap_flag, unsigned int *pfeature); #define setup_force_cpu_cap(bit) do { \ set_cpu_cap(&boot_cpu_data, bit); \ diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c index 3d633f67fbd7..1a71434f7b46 100644 --- a/arch/x86/kernel/cpu/cpuid-deps.c +++ b/arch/x86/kernel/cpu/cpuid-deps.c @@ -120,3 +120,29 @@ void setup_clear_cpu_cap(unsigned int feature) { do_clear_cpu_cap(NULL, feature); } + +/** + * find_cpu_cap - Given a cap flag string, find its corresponding feature bit. + * @cap_flag: cap flag string as defined in x86_cap_flags[] + * @pfeature: feature bit + * + * Return: true if the feature is found. false if not found + */ +bool find_cpu_cap(char *cap_flag, unsigned int *pfeature) +{ +#ifdef CONFIG_X86_FEATURE_NAMES + unsigned int feature; + + for (feature = 0; feature < NCAPINTS * 32; feature++) { + if (!x86_cap_flags[feature]) + continue; + + if (strcmp(cap_flag, x86_cap_flags[feature]) == 0) { + *pfeature = feature; + + return true; + } + } +#endif + return false; +} diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index 88bbba7ee96a..99b895eea166 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -256,7 +256,8 @@ static void __init clear_cpuid(void) /* Chang command line range for next search. */ cmdline_size = option_pos - boot_command_line + 1; argptr = arg; - if (get_option(&argptr, &bit) && + /* cpu cap can be specified by either feature bit or string */ + if ((get_option(&argptr, &bit) || find_cpu_cap(arg, &bit)) && bit >= 0 && bit < NCAPINTS * 32) setup_clear_cpu_cap(bit); }