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 24B07CAC598 for ; Tue, 16 Sep 2025 14:38:50 +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=XWCpQ7e6e5cWUCkciMXT4EsynaoCqfnEnjJlGuCHERs=; b=F5sX8AwKTU0p7BzdKPr4HeaEFl A2nz+FEbgTKi2LQjELFhwGCxm3ZtQtPQAq6iRXkRwCW4PxcJrp5RlaGSXzLKMb8edB9mobHn++UbJ TVcHgHbX/jnEZ6V1pcxuYcbMZX76VNtDqJVNmXonD/JJm1oYqRB9EUpHXrJJXPRUcnfzGjFaYe1ub WWgW4MfPVk+ZqUk3/8E717eYOgtAQj8nsz6Oo9d6/93YBBI6KhbGU4aTnExGd3h3oLxpcwWYzefJA ytyaGtNXm+oDSg4x9RXO6y/GjqmSkfsoD9fpUAGAcmiGFbTYPKAMvDmO2pqBa/6I+CBMqOlbm1xos OtCgb7bg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uyWpL-000000089dZ-2aFM; Tue, 16 Sep 2025 14:38:39 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uyWpI-000000089cj-2QI3 for linux-arm-kernel@lists.infradead.org; Tue, 16 Sep 2025 14:38:37 +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 9D046FEC; Tue, 16 Sep 2025 07:38:27 -0700 (PDT) Received: from bogus (e133711.arm.com [10.1.196.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 22BEE3F673; Tue, 16 Sep 2025 07:38:33 -0700 (PDT) Date: Tue, 16 Sep 2025 15:38:31 +0100 From: Sudeep Holla To: Andre Przywara Cc: Mark Rutland , Sudeep Holla , Lorenzo Pieralisi , , , , Chao Gao , Ard Biesheuvel , Salman Nabi Subject: Re: [RFC PATCH 0/1] Arm Live Firmware activation support Message-ID: <20250916-energetic-debonair-mongrel-dfcafb@sudeepholla> References: <20250625142722.1911172-1-andre.przywara@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250625142722.1911172-1-andre.przywara@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250916_073836_660200_01C0B94C X-CRM114-Status: GOOD ( 21.44 ) 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 On Wed, Jun 25, 2025 at 03:27:21PM +0100, Andre Przywara wrote: > Hi, > > (please feel free to add people interested on this from the x86 side > as you see fit) > > this is a proposal for a driver for the Arm Live Firmware Activation (LFA) > specification[1]. LFA provides an interface to allow "activating" firmware > updates without a reboot. > In contrast to Intel's TDX [2] approach (which seems only concerned about > some confidential computing related firmware blob), and even OCP's > "impactless" updates[3], the Arm approach just lists a number of > "activatable" firmware images, and does not limit their scope. In > particular those updates can (and will) be for firmware bits used by the > application processors (which OCP seems to rule out), including runtime > secure firmware (TF-A/BL31), confidential compute firmware, and > potentially even UEFI runtime firmware. > Initially we have the whole chain demoing the Arm Confidential Computing > firmware (RMM) update, which is conceptually the same as Intel's TDX > proposal. > > So our design approach is to create a directory under /sys/firmware, and > just list all images there, as directories named by their GUID. > Then the properties of each image can be queried and the activation > triggered by the sysfs files inside each directory. For details see the > commit message of the patch. > This is admittedly a somewhat raw interface, though even in that form > it's good enough for testing. Eventually I would expect some fwupd > plugin to wrap this nicely for any admins or end users. > > The purpose of this RFC is to get some feedback on the feasibility of > this interface, and to understand how this would relate to the other two > approaches (TDX + OCP "impactless" updates). > Thanks for the details and I agree we need opinions from x86 community if possible but definitely from cloud/hyperscale community using these user interfaces ? While x86 and Arm may provide its own user interface, are hyperscale community happy with that ? I briefly read the unified (arch agnostic) requirements specification [3] but will there be a requirement to have a unified user interface from the OS ? We don't want to define something Arm specific to just abandon it quickly if and when hyperscale community comes back with such a request for unified user interface. I am not against having Arm specific interface, just getting clarification in terms of requirements even before diving into technical review of the patch here. Anyone from hyperscale community ? Please provide directions here. -- Regards, Sudeep