From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793376136; b=CpM8vGQYBy7osTVcmUiKveAU1YYuhgFPC19M6ntjLaAt7IqpLyLm8CaVyjSfkb5IBfZX UoIHWEtunDVXyoDGEhu1asq3owyFK0ivDI0xrcIV517DCFKIvXrRt6/cb7Dw0S43afKxI I5Pbdd7sTz/5PU2owVR4lIAn293YjzvMf4bug9p/5KEOiwSoyb2DGy23LcyGzIFMgvxM6 pAlvaN+aFcXvSrTSBQumIbjtF1NN7CZMmnRruCUBF56YdMqkfJttjQLgTMx+10RQdBAtz RBdI2seOda6FB/9+i9ibMI9AhHINSCCKot/qd5+Qkgrm65shvEfyF0qSJuYrKs0B4xw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793376136; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=IID0IQrwer6PQmdAFn1eniEo1UtSssILBqJFeXxXuX8=; b=DxzwzMwAQesAV6r1SdICVRgYFy+1w2Fo+nSkAgXKfZ1027hlZSMrAXwgPSCDA4uPWjxR 2oQtr/uHs8g5q33xIyAnKPdBgt+VxkM/GsguV1SPsy4ETv8y/qow60TgVifTS2czqHCqj WhfSMbTzno/tZheebIazCuc80ue8nqseT52JFN3hhIXcOJHo7/926ZfD2n3Hfuci5w/MN eOOOYUmQbliLB8mTBlQgoh3ej9Vg763/sqY2DzIvStKjGM2oPZAgtmcHQP/x1TcEaRY7H QSlZ/L93bPLkbbuDyIoGwz7aNx3yaZkTms0cIvKfnrpgsSXoxGw9blHpI7AZQrcu//A== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Q5XQ3b9Q; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with UTF8SMTPS id E0059606A31A; Fri, 30 Oct 2026 16:02:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Q5XQ3b9Q Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id E65E71F0093A; Fri, 30 Oct 2026 16:02:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793376135; bh=IID0IQrwer6PQmdAFn1eniEo1UtSssILBqJFeXxXuX8=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Q5XQ3b9Qof6LCbx/LGxFlcpMZ9xsw9w03YWHAQr+RSTlGqIFJCz9Ds6u6VVCgEoyZ 8MO4wq50vIbdEFDQG5QqWGuxWTezNOQSs9uJGDLXUP/g3DWdG+NxF8lHhnnQka+R7w W2TVUUEUo/yI9uXy2T1BuaK3SjJcgAOABg+C8bMlpqM0CfDz37MflaDf9QX1aWiAU3 n6Ksctl8CoFg2DU5dLoYNXB7VMR5tk/9Fhl2jb+8wWXNpB82Yn9wbTbkZqQ6Ai4sfA SoYkxvVo81pyjr3yTaGQwUYSRUlHTLQFCxbmeRgItLKv97ddqe0ttBF9iUFmJ7Buxk pd6mTS6/9jmcg== Date: Fri, 30 Oct 2026 18:02:11 +0200 From: Jarkko Sakkinen To: Arun Menon Cc: linux-kernel@vger.kernel.org, Jason Gunthorpe , Peter Huewe , linux-integrity@vger.kernel.org Subject: Re: [PATCH v5 0/7] tpm_crb: Add command and response buffer chunking support Message-ID: References: <20261029181541.99505-1-armenon@redhat.com> X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Fri, Oct 30, 2026 at 01:30:21AM +0200, Jarkko Sakkinen wrote: > On Thu, Oct 29, 2026 at 11:45:34PM +0530, Arun Menon wrote: > > The new version of TCG TPM v185 [1] supports sending data/commands in > > chunks for the CRB (Command Response Buffer) interface. This is in line > > with the initiative to support PQC algorithms. > > > > This series implements the logic to send and receive larger TPM > > cmd/rsp between the linux guest and the TPM backend in chunks. > > Currently, the TPM CRB driver is limited by the physical size of the > > MMIO window. When userspace attempts to send a payload that exceeds this > > size, the driver rejects it. > > > > This series introduces chunking support. The driver now checks the CRB > > interface capability for CRB_INTF_CAP_CRB_CHUNK. If supported by the > > backend, the driver will slice oversized commands into MMIO-sized > > chunks, signalling the backend via CRB_START_NEXT_CHUNK, and finalizing > > with CRB_START_INVOKE. Responses are also read back in a similar chunked > > manner. > > > > If the backend does not support chunking, the driver retains its legacy > > behaviour and enforces the standard size limits. > > > > This feature also requires the QEMU to interpret the data in chunks and > > forward it to the TPM backend and subsequently dispatch the TPM response > > in chunks back to the linux guest. This is implemented in [2] and > > already merged into the mainline. > > > > The whole series applied on top of for-next-tpm (including prerequisite) > > can be found here: > > https://github.com/armenon-rh/linux/tree/tpm-crb-linux > > > > [1] https://trustedcomputinggroup.org/wp-content/uploads/PC-Client-Specific-Platform-TPM-Profile-for-TPM-2p0-v1p07_Pub.pdf > > [2] https://lore.kernel.org/qemu-devel/20260601215410.517009-1-stefanb@linux.ibm.com/ > > > > v5 > > -- > > - Split [PATCH v4 06/06] into 2. The preparation patch separates the > > no-chunking send() and recv() from chunking. > > - Fixed block comments to respect kernel's preferred multi-line style. > > - Added citations to the TCG TPM and NIST FIPS documentations. Explained > > the logic and newly introduced registers in brief in the git commit > > message. > > > > v4 > > -- > > - Rebased on master (or for-next-tpm, both point to the same commit). > > - Resolved one conflict in PATCH v3 05/06, as TPM_BUFSIZE is declared in > > include/linux/tpm_command.h. > > > > v3 > > -- > > - Split patch 2, so that the code is cleaner. > > - Re-order the buffer size adjustment patch. > > - Rename crb_trigger_tpm to tpm_crb_start. > > - Add dispatching logic in send and recv functions. Chunking is > > separated from no-chunking for clarity. > > - Increase TPM_BUFSIZE in the common file include/linux/tpm.h following, > > [PATCH v9 11/11] tpm-buf: Implement managed allocations > > https://lore.kernel.org/linux-integrity/20260125192526.782202-12-jarkko@kernel.org/ > > > > v2 > > -- > > - Add size checks before copying memory. > > - Update TPM_BUFSIZE to 8KB. > > - Commit messages updated to indicate motivation and logic of the change. > > > > Arun Menon (7): > > tpm_crb: Add register definitions of TPM CRB chunking fields > > tpm_crb: Split start method into a separate header > > tpm_crb: Add start_cmd parameter to tpm_crb_start wrapper > > tpm: tis_i2c: Use local 4KB buffer to limit memory usage > > tpm: Increase TPM_BUFSIZE to 8KB for chunking support > > tpm_crb: Factor crb_send()/crb_recv() bodies into helpers > > tpm_crb: Implement command and response chunking logic > > > > drivers/char/tpm/tpm_crb.c | 226 +++++++++++++++++++++++++++------ > > drivers/char/tpm/tpm_tis_i2c.c | 6 +- > > include/linux/tpm_command.h | 2 +- > > 3 files changed, 189 insertions(+), 45 deletions(-) > > > > -- > > 2.56.0 > > > > Applied, thank you. Could you send +1 version that: 1. Applies to my master. 2. There was one issue that kernel test bot complained. The issue: >> drivers/char/tpm/tpm_crb.c:464:34: sparse: sparse: cast removes address space '__iomem' of expression No worries, just every other day stuff but would help me if you carry out these, thanks. And yeah, the first one is not even a real issue, just unfortuate coincident :-) I'll apply it as soon as I get it. Br, Jarkko