From patchwork Thu Sep 14 03:23:27 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Yang, Weijiang" X-Patchwork-Id: 139586 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a05:612c:172:b0:3f2:4152:657d with SMTP id h50csp347372vqi; Thu, 14 Sep 2023 06:26:46 -0700 (PDT) X-Google-Smtp-Source: AGHT+IG4jzcPpIYKBONibnIHnU4wtEI4y9sVuky98P9M8zngXOAcDk4bM9i7uqBAMsOvnOl2cyw3 X-Received: by 2002:a17:90a:de88:b0:268:553f:1938 with SMTP id n8-20020a17090ade8800b00268553f1938mr4938581pjv.4.1694698005632; Thu, 14 Sep 2023 06:26:45 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1694698005; cv=none; d=google.com; s=arc-20160816; b=BOf9+sz6/PwFTHUlyzelNAwQXEqXl68rYd/VkfISnfQnrnp2Ro0hz5Ik04t1bVkV9I xe0ZrxquKBklLTTcYGRKUTdH5zJS4VBBr9AAzyOGkxMh5l1zHgCEH34Nx449udfpwWiv DSOOeE3SmTxZlTgoah67rRxooGRP2tb4Ay3fXlqD+w212JhrRl+1jp7KzlEjjiy/7u9d rmKiYrrasKTVJgx9rNgR4HI2XM0h1Pt/s6hFGnEkBvF7AMZnEBPHnkn06Ud9oik3qQRP En3gwst4CDJ2IAH77OiO9ElUixvKWWlmxrYn5m9K61Vs+n2bmYxPkw6wcx6NP0pMwi90 K0Og== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=xVABnXeOkMZlJo+ZffrqSfE/4k2ea3Z1/0rzSIi4N90=; fh=VKDky7JI6Mwho+jW2kjyYjgneGFqVaPlgJX6sIBNvQM=; b=Ko78gGyu+tn5Da5d1rwd5rlYxmPFXzuKXjtvJ5OwCOZ/W3Qhs2mpHOMfM0+p/3GgL/ KFL3IRgiyPtE7+ee3kixnU3QI7i53XTB9K6qq1Vh4rixJRhpP+evXQjbWWZmVJPU9k2H cS7D65ScKhq0p7oQdVcuP5Gkj4iwecPqFw4rynGvsJxwzog7SX+fjXO3iA8CGW/IX285 ZUY/kUETbGKUMFpt3SsvJcnN+VDMaR2lLT2zRh+xsD5+Q5/HikPT0XnLTo0HchrazOMw DLvr8aYcp4DqzZhPx+kg3BV/SkYnBMUTtsxF79ouQ67QPCx9Wzhu5HWogqfagkaq0kDr /mOg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@intel.com header.s=Intel header.b=Erj7Y+SG; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:6 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from pete.vger.email (pete.vger.email. [2620:137:e000::3:6]) by mx.google.com with ESMTPS id az18-20020a17090b029200b00263eb5054fdsi3730440pjb.32.2023.09.14.06.26.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 14 Sep 2023 06:26:45 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:6 as permitted sender) client-ip=2620:137:e000::3:6; Authentication-Results: mx.google.com; dkim=pass header.i=@intel.com header.s=Intel header.b=Erj7Y+SG; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:6 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by pete.vger.email (Postfix) with ESMTP id AB06581A3282; Wed, 13 Sep 2023 23:29:05 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at pete.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235433AbjING2s (ORCPT + 35 others); Thu, 14 Sep 2023 02:28:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46364 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232171AbjING2q (ORCPT ); Thu, 14 Sep 2023 02:28:46 -0400 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5103BF9; Wed, 13 Sep 2023 23:28:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1694672922; x=1726208922; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=0H4/DsmRdq6ZAqAGPRiCyRQ3eI7Btuj1gad9cmvRYIo=; b=Erj7Y+SGRTMfMtKFj4T5JjoATZ8yWnkb50Dqtua6w0ULPbXekPebMXT5 lIa9msZG797l2eubx0d/SzRQ7bt6RCCJ6pmxZo3i8npMTcGbzD+fwoBs4 sBCzheKjV10UGqH9FlX07wQ7hLNCG8qAHqPfWfMZNtrlOCwLiVw1RcCI8 13M3QatZBpcm5Tk9KougOrZylOsAMFwmmzu0ItoMwCdKWRCVab9RjOb8x nQ9HlOO9NQJMh754lShr9erzOA3l7ovD5JDERynaYWkarl5op6/jEm74c jJbOjSDvkw4CCcYsnQGPCoAjfqFfYTZhdqHf8Y7+H2Zg29e39rk1YniQy A==; X-IronPort-AV: E=McAfee;i="6600,9927,10832"; a="382672437" X-IronPort-AV: E=Sophos;i="6.02,145,1688454000"; d="scan'208";a="382672437" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Sep 2023 23:28:41 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10832"; a="809937978" X-IronPort-AV: E=Sophos;i="6.02,145,1688454000"; d="scan'208";a="809937978" Received: from embargo.jf.intel.com ([10.165.9.183]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Sep 2023 23:28:41 -0700 From: Yang Weijiang To: x86@kernel.org, linux-kernel@vger.kernel.org Cc: dave.hansen@intel.com, tglx@linutronix.de, peterz@infradead.org, seanjc@google.com, pbonzini@redhat.com, rick.p.edgecombe@intel.com, kvm@vger.kernel.org, yang.zhong@intel.com, jing2.liu@intel.com, chao.gao@intel.com, Yang Weijiang Subject: [RFC PATCH 1/8] x86/fpu/xstate: Manually check and add XFEATURE_CET_USER xstate bit Date: Wed, 13 Sep 2023 23:23:27 -0400 Message-Id: <20230914032334.75212-2-weijiang.yang@intel.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20230914032334.75212-1-weijiang.yang@intel.com> References: <20230914032334.75212-1-weijiang.yang@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (pete.vger.email [0.0.0.0]); Wed, 13 Sep 2023 23:29:05 -0700 (PDT) X-Spam-Status: No, score=0.2 required=5.0 tests=DATE_IN_PAST_03_06, DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on pete.vger.email X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1777019656137815707 X-GMAIL-MSGID: 1777019656137815707 Remove XFEATURE_CET_USER entry from dependency array as the entry doesn't reflect true dependency between CET features and the xstate bit, instead manually check and add the bit back if either SHSTK or IBT is supported. Both user mode shadow stack and indirect branch tracking features depend on XFEATURE_CET_USER bit in XSS to automatically save/restore user mode xstate registers, i.e., IA32_U_CET and IA32_PL3_SSP whenever necessary. Although in real world a platform with IBT but no SHSTK is rare, but in virtualization world it's common, guest SHSTK and IBT can be controlled independently via userspace app. Signed-off-by: Yang Weijiang --- arch/x86/kernel/fpu/xstate.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index cadf68737e6b..12c8cb278346 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -73,7 +73,6 @@ static unsigned short xsave_cpuid_features[] __initdata = { [XFEATURE_PT_UNIMPLEMENTED_SO_FAR] = X86_FEATURE_INTEL_PT, [XFEATURE_PKRU] = X86_FEATURE_OSPKE, [XFEATURE_PASID] = X86_FEATURE_ENQCMD, - [XFEATURE_CET_USER] = X86_FEATURE_SHSTK, [XFEATURE_XTILE_CFG] = X86_FEATURE_AMX_TILE, [XFEATURE_XTILE_DATA] = X86_FEATURE_AMX_TILE, }; @@ -798,6 +797,14 @@ void __init fpu__init_system_xstate(unsigned int legacy_size) fpu_kernel_cfg.max_features &= ~BIT_ULL(i); } + /* + * Manually add CET user mode xstate bit if either SHSTK or IBT is + * available. Both features depend on the xstate bit to save/restore + * CET user mode state. + */ + if (boot_cpu_has(X86_FEATURE_SHSTK) || boot_cpu_has(X86_FEATURE_IBT)) + fpu_kernel_cfg.max_features |= BIT_ULL(XFEATURE_CET_USER); + if (!cpu_feature_enabled(X86_FEATURE_XFD)) fpu_kernel_cfg.max_features &= ~XFEATURE_MASK_USER_DYNAMIC;