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 75976C433F5 for ; Tue, 26 Oct 2021 16:17:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56C87604AC for ; Tue, 26 Oct 2021 16:17:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237551AbhJZQTq (ORCPT ); Tue, 26 Oct 2021 12:19:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237302AbhJZQTH (ORCPT ); Tue, 26 Oct 2021 12:19:07 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 87D51C061767; Tue, 26 Oct 2021 09:16:43 -0700 (PDT) Date: Tue, 26 Oct 2021 16:16:41 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1635265002; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Sf3hsFvAeN6w31Awm4Gs0A2G56VZ2NPNAKygrJsqexY=; b=uOtGX5tiSD3hW5k8/CN71FOF+0FTyrjAAWKbMt5iLyox1/am7/mCRF5G3cwuFf8L2OjMJI rm0RABajh+w4EM+AGsoXp1HgxN9AhnGZNeJ0Ls5v7N7SkX8Sod5jNIQ889QfwdNfKvCyp2 P92ZnA5vYLPFM0r9OK0B5T/VVXQ+AMalwAOcWgQTpYAq9Y+E8+rSxFT5+7B+MFcTO4gSGH UDS/DE7rciW3xklWP/QGp8uw1aoJNd8VTz/ZhUhdM27yGQBRQQE62PeWdTnRpXMueERC0g 5xPsazEIhnQjB525VqN+1sEfMl7Rv3ULUrJ2lhDlXv7pKECteS7NBdZl5HNTvw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1635265002; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Sf3hsFvAeN6w31Awm4Gs0A2G56VZ2NPNAKygrJsqexY=; b=TeC1vDoFbDwxhlQe5DjjByiQFp7PWD4KHv7QRxrergotM1OZ+0gQXG33CFYt5wdGHdOkRW hbSwzqRf3RBYLzBQ== From: "tip-bot2 for Chang S. Bae" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/fpu] x86/cpufeatures: Add eXtended Feature Disabling (XFD) feature bit Cc: "Chang S. Bae" , Thomas Gleixner , Borislav Petkov , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20211021225527.10184-13-chang.seok.bae@intel.com> References: <20211021225527.10184-13-chang.seok.bae@intel.com> MIME-Version: 1.0 Message-ID: <163526500132.626.5263605512679379351.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/fpu branch of tip: Commit-ID: c351101678ce54492b6e09810ec02efc0df036a9 Gitweb: https://git.kernel.org/tip/c351101678ce54492b6e09810ec02efc0df036a9 Author: Chang S. Bae AuthorDate: Thu, 21 Oct 2021 15:55:16 -07:00 Committer: Borislav Petkov CommitterDate: Tue, 26 Oct 2021 10:18:09 +02:00 x86/cpufeatures: Add eXtended Feature Disabling (XFD) feature bit Intel's eXtended Feature Disable (XFD) feature is an extension of the XSAVE architecture. XFD allows the kernel to enable a feature state in XCR0 and to receive a #NM trap when a task uses instructions accessing that state. This is going to be used to postpone the allocation of a larger XSTATE buffer for a task to the point where it is actually using a related instruction after the permission to use that facility has been granted. XFD is not used by the kernel, but only applied to userspace. This is a matter of policy as the kernel knows how a fpstate is reallocated and the XFD state. The compacted XSAVE format is adjustable for dynamic features. Make XFD depend on XSAVES. Signed-off-by: Chang S. Bae Signed-off-by: Thomas Gleixner Signed-off-by: Chang S. Bae Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20211021225527.10184-13-chang.seok.bae@intel.com --- arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/kernel/cpu/cpuid-deps.c | 1 + 2 files changed, 2 insertions(+) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index d0ce5cf..ab7b3a2 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -277,6 +277,7 @@ #define X86_FEATURE_XSAVEC (10*32+ 1) /* XSAVEC instruction */ #define X86_FEATURE_XGETBV1 (10*32+ 2) /* XGETBV with ECX = 1 instruction */ #define X86_FEATURE_XSAVES (10*32+ 3) /* XSAVES/XRSTORS instructions */ +#define X86_FEATURE_XFD (10*32+ 4) /* "" eXtended Feature Disabling */ /* * Extended auxiliary flags: Linux defined - for features scattered in various diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c index defda61..d9ead9c 100644 --- a/arch/x86/kernel/cpu/cpuid-deps.c +++ b/arch/x86/kernel/cpu/cpuid-deps.c @@ -75,6 +75,7 @@ static const struct cpuid_dep cpuid_deps[] = { { X86_FEATURE_SGX_LC, X86_FEATURE_SGX }, { X86_FEATURE_SGX1, X86_FEATURE_SGX }, { X86_FEATURE_SGX2, X86_FEATURE_SGX1 }, + { X86_FEATURE_XFD, X86_FEATURE_XSAVES }, {} };