From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 08EF02753F0; Thu, 13 Feb 2025 23:38:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739489930; cv=none; b=FVlO4BblfAq4iTG46ER4cJs41weMeiUcmaEom3gVRUjDzikm79tqCnIBHrpBlW3JtKhSdGHJ9+Cq/qkQ3nxQoByS0HlJzTgyOXMYuPW1N+uPcBb6cKSQoOetuuFJQdyN/5sNE/JLoaBba6iYxY3cPa9VrZ5e6ua435FpqDcy87g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739489930; c=relaxed/simple; bh=v6IHM/pxIvxj98+aTOVZqxpx5vGcbXDyQaxvorp5I7Y=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=hzEeYiAVZCR1a6iw8DXZzPfFNJBZRQAJEyrq1G0pASNGiaFWy1+r7SvWhl8czXa28Ld/1cnSpCJHkCxhZ+jT7JJOpoc1CWIYeGsrrgf18z8f70E/oRdBa+5Uv5UCZPoPiGq8hnVg3JFgrfiPI+eTRZvLC/rd9/gNOFArHrSVyqg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VmvL+KPv; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VmvL+KPv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E33FBC4CED1; Thu, 13 Feb 2025 23:38:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739489929; bh=v6IHM/pxIvxj98+aTOVZqxpx5vGcbXDyQaxvorp5I7Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VmvL+KPv4oNJUNysvNVXIBnEIyY8flT2991GHnnh9UPZBUqt6goLe27jyMT7dR9JZ uX5BZ3mH0B0HWyEdu5e8B+u3uxYkb3mfoGWbOfGJnKrVqxAoJlZFA3B9RJujRm9gJH 0G8tsDF9kRFtLvShjhQMM7lOMSAi/MucIHlUIZgZrQwOmKk79gMI/DuqAqUIW5fTX/ 0E6O/kMwPWhoaFco68hRP7PdT2tmmAb5lHx2p034i/svSF1RbFnUj9szIWiMHptyXc GM50RpNkasNFmzwzMb9L0gVfcQ68AXDWdMRpLG1VsvjfCjO4I6rDbuw8/JTv6MVCgY 9HWV77KaJLupQ== Date: Fri, 14 Feb 2025 01:38:44 +0200 From: Jarkko Sakkinen To: Stuart Yoder Cc: linux-integrity@vger.kernel.org, peterhuewe@gmx.de, jgg@ziepe.ca, sudeep.holla@arm.com, rafael@kernel.org, lenb@kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 5/5] Documentation: tpm: add documentation for the CRB FF-A interface Message-ID: References: <20250212220548.400447-1-stuart.yoder@arm.com> <20250212220548.400447-6-stuart.yoder@arm.com> Precedence: bulk X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Feb 13, 2025 at 04:17:56PM -0600, Stuart Yoder wrote: > > > On 2/13/25 4:11 PM, Jarkko Sakkinen wrote: > > On Wed, Feb 12, 2025 at 04:05:48PM -0600, Stuart Yoder wrote: > > > Add documentation providing details of how the CRB driver interacts > > > with FF-A. > > > > > > Signed-off-by: Stuart Yoder > > > --- > > > Documentation/security/tpm/tpm_ffa_crb.rst | 65 ++++++++++++++++++++++ > > > 1 file changed, 65 insertions(+) > > > create mode 100644 Documentation/security/tpm/tpm_ffa_crb.rst > > > > > > diff --git a/Documentation/security/tpm/tpm_ffa_crb.rst b/Documentation/security/tpm/tpm_ffa_crb.rst > > > new file mode 100644 > > > index 000000000000..c70f8904a93d > > > --- /dev/null > > > +++ b/Documentation/security/tpm/tpm_ffa_crb.rst > > > @@ -0,0 +1,65 @@ > > > +.. SPDX-License-Identifier: GPL-2.0 > > > + > > > +======================== > > > +TPM CRB over FF-A Driver > > > +======================== > > > + > > > +The TPM Command Response Buffer (CRB) interface is a standard TPM interface > > > +defined in the TCG PC Client Platform TPM Profile (PTP) Specification [1]_. > > > +The CRB provides a structured set of control registers a client uses when > > > +interacting with a TPM as well as a data buffer for storing TPM commands and > > > +responses. A CRB interface can be implemented in: > > > + > > > +- hardware registers in a discrete TPM chip > > > + > > > +- in memory for a TPM running in isolated environment where shared memory > > > + allows a client to interact with the TPM > > > + > > > +The Firmware Framework for Arm A-profile (FF-A) [2]_ is a specification > > > +that defines interfaces and protocols for the following purposes: > > > + > > > +- Compartmentalize firmware into software partitions that run in the Arm > > > + Secure world environment (also know as TrustZone) > > > > Does that also cover ARM CCA? Just a question (not a review question). > > No, CCA is for confidential VMs which is a separate trusted execution > environment and FF-A is not used there. OK, cool, just plain interested :-) > > Thanks, > Stuart BR, Jarkko