From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934414AbdJQQ1o (ORCPT ); Tue, 17 Oct 2017 12:27:44 -0400 Received: from terminus.zytor.com ([65.50.211.136]:55779 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757384AbdJQQ1m (ORCPT ); Tue, 17 Oct 2017 12:27:42 -0400 Date: Tue, 17 Oct 2017 09:23:14 -0700 From: tip-bot for Andi Kleen Message-ID: Cc: peterz@infradead.org, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, hpa@zytor.com, mingo@kernel.org, ak@linux.intel.com, tglx@linutronix.de Reply-To: peterz@infradead.org, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, hpa@zytor.com, ak@linux.intel.com, tglx@linutronix.de, mingo@kernel.org In-Reply-To: <20171013215645.23166-5-andi@firstfloor.org> References: <20171013215645.23166-5-andi@firstfloor.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/fpu] x86/fpu: Make XSAVE check the base CPUID features before enabling Git-Commit-ID: ccb18db2ab9d923df07e7495123fe5fb02329713 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: ccb18db2ab9d923df07e7495123fe5fb02329713 Gitweb: https://git.kernel.org/tip/ccb18db2ab9d923df07e7495123fe5fb02329713 Author: Andi Kleen AuthorDate: Fri, 13 Oct 2017 14:56:44 -0700 Committer: Ingo Molnar CommitDate: Tue, 17 Oct 2017 17:14:57 +0200 x86/fpu: Make XSAVE check the base CPUID features before enabling Before enabling XSAVE, not only check the XSAVE specific CPUID bits, but also the base CPUID features of the respective XSAVE feature. This allows to disable individual XSAVE states using the existing clearcpuid= option, which can be useful for performance testing and debugging, and also in general avoids inconsistencies. Signed-off-by: Andi Kleen Reviewed-by: Thomas Gleixner Cc: Linus Torvalds Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20171013215645.23166-5-andi@firstfloor.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/fpu/xstate.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index f1d5476..fb58129 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -15,6 +15,7 @@ #include #include +#include /* * Although we spell it out in here, the Processor Trace @@ -36,6 +37,19 @@ static const char *xfeature_names[] = "unknown xstate feature" , }; +static short xsave_cpuid_features[] __initdata = { + X86_FEATURE_FPU, + X86_FEATURE_XMM, + X86_FEATURE_AVX, + X86_FEATURE_MPX, + X86_FEATURE_MPX, + X86_FEATURE_AVX512F, + X86_FEATURE_AVX512F, + X86_FEATURE_AVX512F, + X86_FEATURE_INTEL_PT, + X86_FEATURE_PKU, +}; + /* * Mask of xstate features supported by the CPU and the kernel: */ @@ -726,6 +740,7 @@ void __init fpu__init_system_xstate(void) unsigned int eax, ebx, ecx, edx; static int on_boot_cpu __initdata = 1; int err; + int i; WARN_ON_FPU(!on_boot_cpu); on_boot_cpu = 0; @@ -759,6 +774,14 @@ void __init fpu__init_system_xstate(void) goto out_disable; } + /* + * Clear XSAVE features that are disabled in the normal CPUID. + */ + for (i = 0; i < ARRAY_SIZE(xsave_cpuid_features); i++) { + if (!boot_cpu_has(xsave_cpuid_features[i])) + xfeatures_mask &= ~BIT(i); + } + xfeatures_mask &= fpu__get_supported_xfeatures_mask(); /* Enable xstate instructions to be able to continue with initialization: */