From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) (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 5B1BE3054C7; Sat, 19 Sep 2026 04:04:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789790675; cv=none; b=Wvs9Dqv0bxelpRyTWMx812kS8sY7J2OOVW2RtVAcuu636ewVrZT8OYQ25yEJergJGUQXahl7vEkdV/ImFdKgHP7zjSJHE4ZWlKxkdOc33e+wNLivmcTZwssRmVcvwLkGENVZhYLleO1FRX/KIXEyRHZmpIuilSh8ue0egCKvxLs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789790675; c=relaxed/simple; bh=nZJBvPIh95jUAFnRv6ZrsC/RbI3DEcyGbYX5M7J1+5U=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=Wzqe6ktAr9n2FX2JrYgXGgy7tH1xz1+OuO0ITXEOqWt5ePG4BMAnsrbRsMKpMHV4GML38zLywkpFsVgyJFq6aLbNu2Z/XE84FXiopmV8FMzGho1aY7eJ0jFdZsNH1uHnRazF/aHbqn5P1V2Vz/w0yy2WUVL/1LXoHcF+PMNhijs= 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=bcD3Enh1; arc=none smtp.client-ip=192.198.163.11 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="bcD3Enh1" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1789790674; x=1821326674; h=message-id:date:mime-version:cc:subject:to:references: from:in-reply-to:content-transfer-encoding; bh=nZJBvPIh95jUAFnRv6ZrsC/RbI3DEcyGbYX5M7J1+5U=; b=bcD3Enh1pUm/mGYwR0Tbk/NqFoNSN78FvHvJGmwh/Ppu4YYPIzuj8qNV W5CocJyznyeXyGrBgm9AhTxlrg508VBEu2huWr4OQwhQOYODbG+LuX7AT wq4Jt4IGAvCnU0bAmhLfR4fu9kjX6gL0yBYrI+0zG9QmRVylextiwEx31 5POWJA9w5rp43zEQfgKvpzu5QvlqQqAq89tEsR73M8RbNNKCsNlj2IoTW FEA9WuSW+BRt7n11q63OgG9xylv/N34c/x9rkGuoUVteuolgR6v1ThxBI v01StGr8GqniiwJdHURrhJFtvirU7gzRR/PfuBwmhszhvuabDhskQfdq4 Q==; X-CSE-ConnectionGUID: a8kLQKSUS+mpMz7LD+vXzw== X-CSE-MsgGUID: ETAcHml6Tum1Y1k9zDSq6A== X-IronPort-AV: E=McAfee;i="6800,10657,11909"; a="100926605" X-IronPort-AV: E=Sophos;i="6.27,109,1787036400"; d="scan'208";a="100926605" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Sep 2026 21:04:33 -0700 X-CSE-ConnectionGUID: mKrWvurVSxqw55S/Q6751w== X-CSE-MsgGUID: l1N3vmyUSQ2LY2XhlDkSmQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,109,1787036400"; d="scan'208";a="270403709" Received: from unknown (HELO [10.238.1.188]) ([10.238.1.188]) by fmviesa006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Sep 2026 21:04:29 -0700 Message-ID: <48f71e6e-7240-428d-a8a7-31542a880a18@linux.intel.com> Date: Sat, 19 Sep 2026 12:04:27 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Cc: baolu.lu@linux.intel.com, Joerg Roedel , Will Deacon , Robin Murphy , Jason Gunthorpe , Dave Hansen , Kiryl Shutsemau , "Edgecombe, Rick P" , "yilun.xu@linux.intel.com" , "Li, Xiaoyao" , "Gao, Chao" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 0/5] iommu/vt-d: Introduce trusted DMA initialization support To: "Tian, Kevin" , "iommu@lists.linux.dev" , "x86@kernel.org" , "linux-coco@lists.linux.dev" , "kvm@vger.kernel.org" References: <20260915074235.1219183-1-baolu.lu@linux.intel.com> Content-Language: en-US From: Baolu Lu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 9/18/2026 10:30 AM, Tian, Kevin wrote: >> From: Lu Baolu >> Sent: Tuesday, September 15, 2026 3:42 PM >> >> Hi, >> >> This series adds Intel VT-d trusted extension support to the host Intel >> IOMMU driver as groundwork for TEE I/O trusted DMA (e.g. TDX Connect). >> >> The trusted extension introduces a parallel, extension-specific path for >> trusted DMA assets used by confidential device assignment. Existing VT-d >> functionality remains unchanged for regular host DMA paths. >> >> From the TDX Connect architecture perspective, VT-d is enhanced with: >> >> 1) Trusted DMA translation root table >> - A second root-table address register, restricted to SEAM SAI. >> - Programmed by the TDX module with the root of TDX-managed DMA >> translation tables for TD-assigned devices. >> >> 2) Trusted invalidation queue >> - A second invalidation-queue address register plus dedicated >> head/tail registers, also restricted to SEAM SAI. >> >> 3) IOTLB / DID isolation >> - When TDX Connect is enabled, VT-d restricts VMM DID usage and >> reserves the DID MSB namespace bit for TDX-module use. >> >> This posting focuses on VT-d-side enablement only: it enables those >> extension-defined resources and control points while preserving existing >> host VT-d behavior for non-trusted flows. Higher-layer integration >> (TDX guest/device flows) will be posted separately. >> > > Jason had a comment on this from another thread [1]: > > " > Okay, so I saw the driver posting for basic iommu support, can we try > to rework that to be split out like Aneesh is doing so everything > about TDX calls lives in tsm and intel iommu only provides a small API > surface to exchange whatever details are needed to bootstrap TDX > module? > " > > [1] https://lore.kernel.org/all/20260916123954.GC3196566@ziepe.ca/ Yes, I will head in this direction in the next version. Thanks, baolu