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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 20629CA5FD6 for ; Thu, 1 Oct 2026 16:39:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=qq+6EUhmiZleFP8JaAHh/mFkJt4aJ2uekt5AzQtFZ/Q=; b=f8m5Zi2+av9hocSUr28aPRTffO rEzpYAAK3D4jK8QB1iI9zSIdFYxullbBjADbMhj+k31O1Ay4TQGGMPJi4antGfMHvugGAlCSQMVhK gW7OlYFzjD0eVjOTtsPuX0feMIWQxtTyuBC/Boxh4I28nHQ3bln5xyznOALy/m1cL1BTKXj0y0BPQ bJS6uEjGdiw21kyxYZq+ZAE5pwg80W4N1g5odtPuzXhrN+YkpjmWPzaiYWXXY3yZen2GQkGHopeSi A0F50Fxlu6JudfKdMDADNRF9obH1/zySGf/L7H7nqApSRCK+6jaLFVw1BwJjaogtpFIkfImvFMZAU yVF0TNmA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xCJog-00000009k7q-1C8P; Thu, 01 Oct 2026 16:39:30 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xCJoe-00000009k6Q-0sNV for linux-arm-kernel@lists.infradead.org; Thu, 01 Oct 2026 16:39:29 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id EE5E9497; Thu, 1 Oct 2026 09:39:22 -0700 (PDT) Received: from e129823.arm.com (e129823.arm.com [10.2.213.3]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E2E613F85F; Thu, 1 Oct 2026 09:39:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1790872766; bh=q4SvOgTXIsNqlpMUOj2ef8MMWb7VA7YCONSmXTiArQk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=thPgHjGq4KLCxFCMOxTNwhO46NGyh+WVwgUMuprlxt+Nen4cbvbV1B/AetnyZ63cI qjGPOelzghxSe5sU3NpQYJCnPiPTWokp39L+895qwgszRoFOfxxUCOOwc2wmQus0+8 blikHLD31ZKL4WOfKOE2CFaiphHnqEPP7yfAwj2U= Date: Thu, 1 Oct 2026 17:39:20 +0100 From: Yeoreum Yun To: Jason Gunthorpe Cc: Roberto Sassu , Yeoreum Yun , linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Eric Snowberg , linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, Mimi Zohar , Roberto Sassu , Dmitry Kasatkin , Paul Moore , James Morris , "Serge E. Hallyn" , Catalin Marinas , Suzuki Poulose , Steven Price , Sami Mujawar , "Aneesh Kumar K.V" , Jiri Pirko , gongruiqi1@huawei.com Subject: Re: [PATCH RFC 0/3] security: ima: support TSM measurement registers Message-ID: References: <20260930-ima_tgx_integration_v2-v1-0-722c35370548@arm.com> <20261001151801.GC3019323@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261001151801.GC3019323@ziepe.ca> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261001_093928_325104_E1C8A7FF X-CRM114-Status: GOOD ( 24.55 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Jason, > On Thu, Oct 01, 2026 at 01:45:26PM +0200, Roberto Sassu wrote: > > On Thu, 2026-10-01 at 13:27 +0200, Roberto Sassu wrote: > > > On Wed, 2026-09-30 at 14:43 +0100, Yeoreum Yun wrote: > > > > Confidential computing guests without a TPM can use TSM measurement > > > > registers to record IMA measurement digests instead of TPM PCRs. > > > > + Gong Ruiqi, of course. > > We are working very seriously on this same problem too. > > For some time we did investigate extending tsm_mr to do more things, > have a better uAPI, but that eventually evolved into the realization > that tsm_mr is simply too narrowly focused. It looks like James got to > this idea before we did. I agree with his remarks in the 2025 thread > with Gong. > > So we've started work on a new comprehensive "Attestation subsytem" > that will pull in all forms of ROTs, TPM, CC stuff and SPDM use cases > to give a consistent user API to work with this class of HW. In many > ways I view this as a rename of tsm_mr (it will eventually fully > absorb it), but the name evokes the broader goal and encourages > everyone to come in, not just CC world. > > Our overall goal would be for something like systemd to have a single > uniform kernel API that allows it interwork with any ROT someone may > have. A uAPI to do "Extend", "Quote", "Get Log" operations so that the > existing TPM support in systemd can be improved to work on any ROT > flexibly without having to hard code specific ROT behaviors into > systemd. > > I've felt the ultimate end goal would be to make all the in-kernel tpm > users go through the proposed attestation subsystem so they can have > ROT and "PCR profile" agility. Certainly I've heard enough people > asking for this. > > This is a broader topic than just IMA. For example DRTM also has to > use the TPM, and other ROTs. It also brings in a global shift of how > the system wide "PCR Profile" should work as post-DRTM has a different > TPM locality and access to the protected DRTM-only PCRs that are > normally blocked. > > Jiri posted his current state here: > https://lore.kernel.org/r/arzr32ZDComnfmny@FV6GYCPJ69 Thanks to let me know. I'll take a look for this. -- Sincerely, Yeoreum Yun