From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2CBE62BEC2B; Mon, 26 Jan 2026 11:28:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769426893; cv=none; b=eRYW0Z6dJaeVAN7ddpUSSpn4Gdu0FXLJHXtMn159lcso2FwEr0tLkkJkIDxwzaEN0CrQnE8Ap/yXvbcIF4X+c9apSZKVjb2fRwVF6yJxwGytZtZYvtnqP4Zuu8RXw3SFMqFShEu05/q+epivdx42Zt0W0lEDjK3l62UE0YZLxpI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769426893; c=relaxed/simple; bh=k3XR1MT5Vahum7lTIJiF6OhzMhBXDH+X36hEo9UNNiA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=D5sEz50EDu1PKPcc817zcj7Nk1twom3jKRIpIZ+uc4PSzcRvOlJnoM7xZksuNKcV6OijavP6GQGQGWBUTqAhPmTKXCVPOKNQub2hS3yG5h7yscvQprmSlBpML+n+m+5lWqsFIjP2Ye1wJWTkhKkRax4hcXYCpza71ix8RQeZgVo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=hkKOtzru; arc=none smtp.client-ip=192.198.163.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="hkKOtzru" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1769426891; x=1800962891; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=k3XR1MT5Vahum7lTIJiF6OhzMhBXDH+X36hEo9UNNiA=; b=hkKOtzrugiGFrUmvbN36BmHIpPITtdv+337eJpy60kZEUm9bsC/lxy/W dC3OCCH/JeWA9WCu4eLSn6dCwRrNpkrXK1vUbmpPiVt+HyAFtlvq7RTMe ji0tsu1D8rTkzfGrAQUgA7GQ71y1wRw5B966ZGs8py1uwthbhKuzJiO3o xz98rZMTlJJOn6yhVZjLtz1NNo+l8s4ItsEOnaRdxG5ZBO8NOYOoNEPO7 02/fPEEBTCmdR9r1iYyZ3vaBHntc0LLnxhi/P9CipLMnjtHPJBU4RfJzw IJ4z+SM7m0pMRSk8OqCtb/UomlRz4AtzJY0Cnl4aOs/b2Wg6xSpRfgKYg g==; X-CSE-ConnectionGUID: z7cyAr9GSryWZHSP/aKwKA== X-CSE-MsgGUID: fOP39w+5S/aJnp2VJziRmg== X-IronPort-AV: E=McAfee;i="6800,10657,11682"; a="58176432" X-IronPort-AV: E=Sophos;i="6.21,255,1763452800"; d="scan'208";a="58176432" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by fmvoesa110.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jan 2026 03:28:10 -0800 X-CSE-ConnectionGUID: QxIAn7LDS+SbVBcYWTrFaA== X-CSE-MsgGUID: JdqJE326RReXEfKaccWuWA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,255,1763452800"; d="scan'208";a="207258561" Received: from krybak-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.246.55]) by fmviesa007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jan 2026 03:28:04 -0800 Date: Mon, 26 Jan 2026 13:28:01 +0200 From: Tony Lindgren To: Chao Gao Cc: linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org, reinette.chatre@intel.com, ira.weiny@intel.com, kai.huang@intel.com, dan.j.williams@intel.com, yilun.xu@linux.intel.com, sagis@google.com, vannapurve@google.com, paulmck@kernel.org, nik.borisov@suse.com, zhenzhong.duan@intel.com, seanjc@google.com, rick.p.edgecombe@intel.com, kas@kernel.org, dave.hansen@linux.intel.com, vishal.l.verma@intel.com Subject: Re: [PATCH v3 26/26] coco/tdx-host: Set and document TDX Module update expectations Message-ID: References: <20260123145645.90444-1-chao.gao@intel.com> <20260123145645.90444-27-chao.gao@intel.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260123145645.90444-27-chao.gao@intel.com> On Fri, Jan 23, 2026 at 06:55:34AM -0800, Chao Gao wrote: > In rare cases, TDX Module updates may cause TD management operations to > fail if they occur during phases of the TD lifecycle that are sensitive > to update compatibility. > > But not all combinations of P-SEAMLDR, kernel, and TDX Module have the > capability to detect and prevent said incompatibilities. Completely > disabling TDX Module updates on platforms without the capability would > be overkill, as these incompatibility cases are rare and can be > addressed by userspace through coordinated scheduling of updates and TD > management operations. > > To set clear expectations for TDX Module updates, expose the capability > to detect and prevent these incompatibility cases via sysfs and > document the compatibility criteria and indications when those criteria > are violated. Reviewed-by: Tony Lindgren