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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F7E0C433EF for ; Tue, 28 Jun 2022 09:12:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344029AbiF1JMN (ORCPT ); Tue, 28 Jun 2022 05:12:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343557AbiF1JMI (ORCPT ); Tue, 28 Jun 2022 05:12:08 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4A8B311A16 for ; Tue, 28 Jun 2022 02:12:07 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id B293B616D4 for ; Tue, 28 Jun 2022 09:12:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C04FBC3411D; Tue, 28 Jun 2022 09:12:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1656407526; bh=gbZhQSU4/NR13gtRuxjYhIOnCtlwDWWV04C1FZnOxow=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ENx+jqPg8Q1l25f5JlLn1WnvjgZve+34Gk72KKOq3skyrDWZh5BxrS/SnHMp76ANT RefjS5BOV39tLha57CC+2P2lyAu/HfEK+Jgk+/OI3vTOldnq1gArTxpvU44WNtlqRQ ZuO2h7Cm6kwg/0VRG7bxH/tjicVqwRg6LhZXnoi8= Date: Tue, 28 Jun 2022 11:12:03 +0200 From: Greg KH To: Oded Gabbay Cc: "Linux-Kernel@Vger. Kernel. Org" , Dani Liberman Subject: Re: [PATCH 11/12] habanalabs/gaudi2: add tpm attestation info uapi Message-ID: References: <20220627202620.961350-1-ogabbay@kernel.org> <20220627202620.961350-12-ogabbay@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 28, 2022 at 11:51:48AM +0300, Oded Gabbay wrote: > On Tue, Jun 28, 2022 at 9:36 AM Greg KH wrote: > > > > On Mon, Jun 27, 2022 at 11:26:19PM +0300, Oded Gabbay wrote: > > > From: Dani Liberman > > > > > > User will provide a nonce via the ioctl, and will retrieve > > > attestation data of the boot from the tpm, generated using given > > > nonce. > > > > Why not use the normal TPM api instead of a new/custom one? Or is this > > not a "normal" TPM device? If not, you should say what it really is. > > > > thanks, > > > > greg k-h > > Honestly, I'm not that knowledgeable about it. It is hidden behind our > firmware code. We just provide a communication method between the > userspace and the firmware, as the userspace can't interact directly > with the f/w. i.e. The driver is a transparent tunnel, it doesn't > interact with registers of the TPM device itself. The "real" driver is > in our firmware. > > So basically we just got definitions from the f/w how to fetch the > data from them and how to expose it to the user and that's it. > > What to do in this case ? Is this considered a "real" TPM ? I imagine > I won't be able to connect to a standard tpm driver in the kernel as > the h/w is not exposed to me. How is this hardware designed? Is the TPM in here supposed to be a real TPM for userspace to use? Or is this just a random hardware thing that you use to validate your device somehow and is not supposed to be a normal TPM as per the specification? thanks, greg k-h