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[23.128.96.18]) by mx.google.com with ESMTP id gz15si19320219ejc.141.2021.10.12.10.57.37; Tue, 12 Oct 2021 10:58:25 -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 S232740AbhJLR51 (ORCPT + 99 others); Tue, 12 Oct 2021 13:57:27 -0400 Received: from mga07.intel.com ([134.134.136.100]:64303 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229554AbhJLR50 (ORCPT ); Tue, 12 Oct 2021 13:57:26 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10135"; a="290720335" X-IronPort-AV: E=Sophos;i="5.85,368,1624345200"; d="scan'208";a="290720335" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Oct 2021 10:55:23 -0700 X-IronPort-AV: E=Sophos;i="5.85,368,1624345200"; d="scan'208";a="562768804" Received: from akleen-mobl1.amr.corp.intel.com (HELO [10.209.115.208]) ([10.209.115.208]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Oct 2021 10:55:21 -0700 Message-ID: <4fe8d60a-2522-f111-995c-dcbefd0d5e31@linux.intel.com> Date: Tue, 12 Oct 2021 10:55:20 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH v5 16/16] x86/tdx: Add cmdline option to force use of ioremap_host_shared Content-Language: en-US To: "Michael S. Tsirkin" Cc: Kuppuswamy Sathyanarayanan , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Peter Zijlstra , Andy Lutomirski , Bjorn Helgaas , Richard Henderson , Thomas Bogendoerfer , James E J Bottomley , Helge Deller , "David S . Miller" , Arnd Bergmann , Jonathan Corbet , Paolo Bonzini , David Hildenbrand , Andrea Arcangeli , Josh Poimboeuf , Peter H Anvin , Dave Hansen , Tony Luck , Dan Williams , Kirill Shutemov , Sean Christopherson , Kuppuswamy Sathyanarayanan , x86@kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-alpha@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, sparclinux@vger.kernel.org, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, virtualization@lists.linux-foundation.org References: <20211009003711.1390019-1-sathyanarayanan.kuppuswamy@linux.intel.com> <20211009003711.1390019-17-sathyanarayanan.kuppuswamy@linux.intel.com> <20211009070132-mutt-send-email-mst@kernel.org> <8c906de6-5efa-b87a-c800-6f07b98339d0@linux.intel.com> <20211011075945-mutt-send-email-mst@kernel.org> <9d0ac556-6a06-0f2e-c4ff-0c3ce742a382@linux.intel.com> <20211011142330-mutt-send-email-mst@kernel.org> From: Andi Kleen In-Reply-To: <20211011142330-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > I mean ... it's already wide spread. I meant wide spread usage with confidential guests. > If we support it with TDX > it will be used with TDX. It has some security trade offs. The main reason to use TDX is security. Also when people take the VT-d tradeoffs they might be ok with the BIOS trade offs too. -Andi