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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8E61C433EF for ; Mon, 28 Feb 2022 23:37:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230459AbiB1Xi0 (ORCPT ); Mon, 28 Feb 2022 18:38:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34554 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230385AbiB1XiV (ORCPT ); Mon, 28 Feb 2022 18:38:21 -0500 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1875FB53 for ; Mon, 28 Feb 2022 15:37:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1646091461; x=1677627461; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=U/t/NO7v7v04FSloHWhwgLX+nBzRWnrhid4LK4Wglb4=; b=GbbFIj/bVobtXVvmHwQU8eo12hp6KW0cALGGteAvencoZAfg8HvjhNU7 YqTKT1t1ik+eUHZEg1cKwsYn3hM9bHBzXjCzQxgTER0cgS6uN4TkQg+lg EKd/pXiRA+BtftoHwQj0N0uRugLNlT7FfeM+BpMWqLlHOjUHh//GhNP+m 74HXDsDnF+6v9m7F1xVvZtfUvdrGUDqgo8VJQSq8YDqNmUCwd+HaSJHkn Xmp1oQT4Lj9ZKW8MGje7g2A9POEpRp4ASvJOHUpdYXHBJqqRt3XBCPLsO dDy68jAvgx9YZ7zcmXJVQW31ZaJ943eKaNL+Di3okw5u67lacL9Z97kBE w==; X-IronPort-AV: E=McAfee;i="6200,9189,10272"; a="251844962" X-IronPort-AV: E=Sophos;i="5.90,144,1643702400"; d="scan'208";a="251844962" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Feb 2022 15:37:40 -0800 X-IronPort-AV: E=Sophos;i="5.90,144,1643702400"; d="scan'208";a="550462413" Received: from simpleku-mobl.amr.corp.intel.com (HELO [10.209.11.92]) ([10.209.11.92]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Feb 2022 15:37:38 -0800 Message-ID: <0f558d9b-a4d8-094b-f3d2-4d9fda945cd9@intel.com> Date: Mon, 28 Feb 2022 15:37:33 -0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCHv4 10/30] x86/tdx: Handle CPUID via #VE Content-Language: en-US To: "Kirill A. Shutemov" Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, luto@kernel.org, peterz@infradead.org, sathyanarayanan.kuppuswamy@linux.intel.com, aarcange@redhat.com, ak@linux.intel.com, dan.j.williams@intel.com, david@redhat.com, hpa@zytor.com, jgross@suse.com, jmattson@google.com, joro@8bytes.org, jpoimboe@redhat.com, knsathya@kernel.org, pbonzini@redhat.com, sdeep@vmware.com, seanjc@google.com, tony.luck@intel.com, vkuznets@redhat.com, wanpengli@tencent.com, thomas.lendacky@amd.com, brijesh.singh@amd.com, x86@kernel.org, linux-kernel@vger.kernel.org References: <20220224155630.52734-1-kirill.shutemov@linux.intel.com> <20220224155630.52734-11-kirill.shutemov@linux.intel.com> <51b6613d-eabd-941d-19b2-95b33ec27e99@intel.com> <20220227010733.abapkmyaroglcafl@black.fi.intel.com> <7a8c4e5e-c0ba-ee8e-a912-c71f89b4d4f2@intel.com> <20220228225336.k3lxk5qqm4vpaocv@black.fi.intel.com> <76b54855-d2b6-e224-ccb4-3f6c4cd1f7e7@intel.com> <20220228233125.z35h5f7lpvspfohv@black.fi.intel.com> From: Dave Hansen In-Reply-To: <20220228233125.z35h5f7lpvspfohv@black.fi.intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/28/22 15:31, Kirill A. Shutemov wrote: >> Does this, in practice, keep TDX guests from detecting any features that >> it supports today? > I scanned through the list of CPUID that probed via #VE during the boot > and they are related to cache/TLB hierarchy enumeration, thermal and > topology. Without cache/TLB enumeration we may miss some optimization. > Topology can be problematic, we may miss ability to communicate the > configuration, I donno. > > Shouldn't be a show-stopper. I can live with that for an initial TDX guest series. Does that bother anyone else?