Received: by 2002:a05:6a11:4021:0:0:0:0 with SMTP id ky33csp842620pxb; Wed, 29 Sep 2021 10:48:13 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzePvjSaaWY42LLSFzar9DDQ8d4uQBiBtZSfKDkCM4cfQVV1YqjPho6cfBG43PVnFAVgIQy X-Received: by 2002:a17:906:180a:: with SMTP id v10mr1267092eje.112.1632937693624; Wed, 29 Sep 2021 10:48:13 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1632937693; cv=none; d=google.com; s=arc-20160816; b=LzfoC7eamrxFTvdtWXx+iszSwZGAp2INP+scC7estIUCfkEEEi8cMNEhPNT1XtY7lO 8vSZpKQXIpwSxLmiDb0u+3IkOLsnRPLaDwWHNGtl8Z1M/1JJW5IEbTvUuHYO0vX7pBSg J1HGx9A8J7z/3BItkMwxFUR3FLiS/DczTnFUWGn41ms3GbTh3liAscwpTcmUVAiJyoeu zThs7ruHEIQeOnaOwWzsFxyOZ9fDCWMPmT60qRpiPy3APIpIUMC1K+oextWVnOHGv9CS BXFgTNX0hlU3Jgvp+A45/ogfeJSmi35PxBf+qD+f3rXcBhNl+NVQEJt7stnoe/a/Td0Q oJhQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:mime-version:content-transfer-encoding :dlp-version:dlp-reaction:dlp-product:content-language :accept-language:in-reply-to:references:message-id:date:thread-index :thread-topic:subject:cc:to:from; bh=xcDYt16IiimBNyRGiznqB7jUt2cTvXa2Xd4q5VjXnr4=; b=uwcqGJcLRjKHQlwT85dC7oSXJQ9p9N0CMMSoriNwMucqb7RuWWl3EVgJrZNfreov+x IS6nb/3hOqj+51+sBSXEWql3Hq7qL/6x0nvZEIKQQU56aPgI0vYyLI+lvh+KGXNZoEYa llssb/3BXtBvVEtkYxvA6uIsuwbxaeJM79QxOPF7CnegL3l8OoOWWH5sfSUlVkb8wXPs 85nZMctmW+GGreIi7kBnvnixyLvFx9Hcm/jTjKzB/JCZ9bsVX+w4lOOm2x4x7WZUUSjb kQfxg50z7LzemSHpY4AOBYUNnZ7NQGBF/aeebAj6WNU3WS2Dbeo54A9tNYWf3UNiN75s pc6Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id v4si520356edi.519.2021.09.29.10.47.49; Wed, 29 Sep 2021 10:48:13 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245565AbhI2QxD convert rfc822-to-8bit (ORCPT + 99 others); Wed, 29 Sep 2021 12:53:03 -0400 Received: from mga18.intel.com ([134.134.136.126]:13848 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243893AbhI2QxD (ORCPT ); Wed, 29 Sep 2021 12:53:03 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10122"; a="212071487" X-IronPort-AV: E=Sophos;i="5.85,332,1624345200"; d="scan'208";a="212071487" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Sep 2021 09:51:21 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.85,332,1624345200"; d="scan'208";a="476702306" Received: from fmsmsx604.amr.corp.intel.com ([10.18.126.84]) by orsmga007.jf.intel.com with ESMTP; 29 Sep 2021 09:51:18 -0700 Received: from fmsmsx612.amr.corp.intel.com (10.18.126.92) by fmsmsx604.amr.corp.intel.com (10.18.126.84) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2242.12; Wed, 29 Sep 2021 09:51:17 -0700 Received: from fmsmsx610.amr.corp.intel.com (10.18.126.90) by fmsmsx612.amr.corp.intel.com (10.18.126.92) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2242.12; Wed, 29 Sep 2021 09:51:15 -0700 Received: from fmsmsx610.amr.corp.intel.com ([10.18.126.90]) by fmsmsx610.amr.corp.intel.com ([10.18.126.90]) with mapi id 15.01.2242.012; Wed, 29 Sep 2021 09:51:15 -0700 From: "Luck, Tony" To: Thomas Gleixner , Peter Zijlstra , Andy Lutomirski CC: "Yu, Fenghua" , Ingo Molnar , Borislav Petkov , "Hansen, Dave" , "Lu Baolu" , Joerg Roedel , "Josh Poimboeuf" , "Jiang, Dave" , "Pan, Jacob jun" , "Raj, Ashok" , "Shankar, Ravi V" , "iommu@lists.linux-foundation.org" , "the arch/x86 maintainers" , Linux Kernel Mailing List Subject: RE: [PATCH 5/8] x86/mmu: Add mm-based PASID refcounting Thread-Topic: [PATCH 5/8] x86/mmu: Add mm-based PASID refcounting Thread-Index: AQHXrlppKq1JNDzwUU2jIMumR+OY2auyKYcA//+tUICAAIgmgIABRuYA//+7QwCAAOhhgIAG/wKAgAArB4D//9OUcA== Date: Wed, 29 Sep 2021 16:51:15 +0000 Message-ID: <57d0e4efcf2d4e9abb91801520a3f386@intel.com> References: <20210920192349.2602141-1-fenghua.yu@intel.com> <20210920192349.2602141-6-fenghua.yu@intel.com> <87y27nfjel.ffs@tglx> <87o88jfajo.ffs@tglx> <87k0j6dsdn.ffs@tglx> <87r1d78t2e.ffs@tglx> In-Reply-To: <87r1d78t2e.ffs@tglx> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-product: dlpe-windows dlp-reaction: no-action dlp-version: 11.6.200.16 x-originating-ip: [10.1.200.100] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > There is zero requirement to look at TIF_NEED_FPU_LOAD or > fpregs_state_valid() simply because the #GP comes straight from user > space which means the FPU registers contain the current tasks user space > state. Just to double confirm ... there is no point in the #GP handler up to this point where pre-emption can occur? -Tony