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 X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2CECAC636CA for ; Sat, 17 Jul 2021 15:35:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 16F3B61159 for ; Sat, 17 Jul 2021 15:35:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235438AbhGQPir (ORCPT ); Sat, 17 Jul 2021 11:38:47 -0400 Received: from mga09.intel.com ([134.134.136.24]:24192 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235193AbhGQPiP (ORCPT ); Sat, 17 Jul 2021 11:38:15 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10047"; a="210853876" X-IronPort-AV: E=Sophos;i="5.84,248,1620716400"; d="scan'208";a="210853876" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jul 2021 08:35:10 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.84,248,1620716400"; d="scan'208";a="631387045" Received: from chang-linux-3.sc.intel.com ([172.25.66.175]) by orsmga005.jf.intel.com with ESMTP; 17 Jul 2021 08:35:10 -0700 From: "Chang S. Bae" To: bp@suse.de, luto@kernel.org, tglx@linutronix.de, mingo@kernel.org, x86@kernel.org Cc: len.brown@intel.com, dave.hansen@intel.com, thiago.macieira@intel.com, jing2.liu@intel.com, ravi.v.shankar@intel.com, linux-kernel@vger.kernel.org, chang.seok.bae@intel.com Subject: [PATCH v8 20/26] x86/fpu/amx: Initialize child's AMX state Date: Sat, 17 Jul 2021 08:28:57 -0700 Message-Id: <20210717152903.7651-21-chang.seok.bae@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210717152903.7651-1-chang.seok.bae@intel.com> References: <20210717152903.7651-1-chang.seok.bae@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Assure that a forked child starts AMX registers in the INIT-state. Signed-off-by: Chang S. Bae Reviewed-by: Len Brown Cc: x86@kernel.org Cc: linux-kernel@vger.kernel.org --- Changes from v5: * Introduced a new define. (Andy Lutomirski) Changes from v4: * Added as a new patch. This was missing on previous versions. --- arch/x86/include/asm/fpu/xstate.h | 3 +++ arch/x86/kernel/fpu/core.c | 3 +++ 2 files changed, 6 insertions(+) diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h index 907f11f95330..80bf107d515c 100644 --- a/arch/x86/include/asm/fpu/xstate.h +++ b/arch/x86/include/asm/fpu/xstate.h @@ -80,6 +80,9 @@ XFEATURE_MASK_INDEPENDENT | \ XFEATURE_MASK_SUPERVISOR_UNSUPPORTED) +/* Volatile states that a child does not inherit. */ +#define XFEATURE_MASK_CLEARED_ON_CLONE XFEATURE_MASK_XTILE + #ifdef CONFIG_X86_64 #define REX_PREFIX "0x48, " #else diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 541628bfc8c0..387118127f93 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -299,6 +299,9 @@ int fpu_clone(struct task_struct *dst) save_fpregs_to_fpstate(dst_fpu); fpregs_unlock(); + if (xfeatures_mask_all & XFEATURE_MASK_CLEARED_ON_CLONE) + dst_fpu->state->xsave.header.xfeatures &= ~XFEATURE_MASK_CLEARED_ON_CLONE; + set_tsk_thread_flag(dst, TIF_NEED_FPU_LOAD); trace_x86_fpu_copy_src(src_fpu); -- 2.17.1