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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 CF710D3B98B for ; Tue, 26 Nov 2024 13:46:59 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tFvtR-0004ZC-P7; Tue, 26 Nov 2024 08:46:17 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tFvtR-0004Yw-2q for qemu-devel@nongnu.org; Tue, 26 Nov 2024 08:46:17 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tFvtO-0002IH-Vc for qemu-devel@nongnu.org; Tue, 26 Nov 2024 08:46:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1732628773; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=ZJTlDIDAnLLiWxccqjWOmK1Gni8JZ4CGXNJVthvIHfw=; b=TaS+gZrJDNjo4dsBKE/kkcbFSRyEIJ3NqdHgTt+/pEuPpDFgnRSVbgIP9fyW/heJC6dyV9 ELzWyHJIrW8H2GJfd4Dqym3IAbR38XPLyNYRbJR/eYaN6zlangp6WkjiEIB71qWqK0AbaE VoXr2LEYsmujnmHDx3Egj+CuSpI94ww= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-99-Cq5oK5N1NiSUkG1mG0Chsg-1; Tue, 26 Nov 2024 08:46:06 -0500 X-MC-Unique: Cq5oK5N1NiSUkG1mG0Chsg-1 X-Mimecast-MFC-AGG-ID: Cq5oK5N1NiSUkG1mG0Chsg Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 54BA319560B4; Tue, 26 Nov 2024 13:46:03 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.147]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id E8E9B1944CC9; Tue, 26 Nov 2024 13:45:58 +0000 (UTC) Date: Tue, 26 Nov 2024 13:45:55 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Stefan Berger Cc: Jean-Philippe Brucker , peter.maydell@linaro.org, richard.henderson@linaro.org, philmd@linaro.org, qemu-arm@nongnu.org, qemu-devel@nongnu.org, alex.bennee@linaro.org, Stefan Berger Subject: Re: [RFC PATCH v3 25/26] target/arm/kvm-rme: Add measurement log Message-ID: References: <20241125195626.856992-2-jean-philippe@linaro.org> <20241125195626.856992-27-jean-philippe@linaro.org> <02b90518-2996-4231-bee9-43ce313669b0@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <02b90518-2996-4231-bee9-43ce313669b0@linux.ibm.com> User-Agent: Mutt/2.2.12 (2023-09-09) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.931, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Mon, Nov 25, 2024 at 05:23:44PM -0500, Stefan Berger wrote: > > > On 11/25/24 2:56 PM, Jean-Philippe Brucker wrote: > > Create an event log, in the format defined by Trusted Computing Group > > for TPM2. It contains information about the VMM, the Realm parameters, > > any data loaded into guest memory before boot and the initial vCPU > > state. > > > > The guest can access this log from RAM and send it to a verifier, to > > help the verifier independently compute the Realm Initial Measurement, > > and check that the data we load into guest RAM is known-good images. > > Without this log, the verifier has to guess where everything is loaded> > and in what order. > > Typically these logs are backed by extensions of TPM PCRs and when you send > a log to a verifier you send a TPM quote along with it for the verifer to > replay the log and check the TPM quote. Also, early code in the firmware is > typically serving as a root of trust that starts the chain of measurements > of code and data, first measuring itself and then other parts of the > firmware before it jumps into the other parts. Now here you seem to just > have a log and no PCR extensions and therefore no quote over PCRs can be > used. Then what prevents anyone from faking this log and presenting a > completely fake log to the verifier? In addition, a measurement log is just one of the interesting features that a TPM provides to OS. The other TPM features are still relevant and useful to confidential VMs. As a high level goal I think we should be aiming to make it possible for users to move their existing VM workloads from non-confidentail to confidential environments, simply as a choice at deployment time. To make this as practical as possible, confidential VMs need to be aiming to match non-confidential VM features where ever it is practical to do so. Users & vendors should not need to build & carry around 2 sets of disk images - one setup for confidential and one setup for non-confidential. Following existing standards will reduce the work both for OS developers, app developers and users alike, to adopt the CVM world. IOW, this is a long winded way of saying that we should be looking to provide a complete *standards compliant*, trusted TPM implementation to confidential VMs, not providing a cherry-picked selection of a few TPM-like features. On the x86 side of things, the route to providing a trusted TPM is via SVSM, both for SNP and TDX. Microsoft's recently open sources openhcl similarly provides a st I don't know so much about RME. Is providing a trusted TPM a job for the RMM ? With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|