From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.160.179 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793283391; b=ZOx79EuaOq+cx4te+MIshE8Jv2/MHSTklObzyb8Bnh34sgjDuBv39rWi3eRyObrt6I3M GGt0QJ/MF1wYjNAfGmkxzby3G+pDOqXnG84JHZjezpxPagO0yrrJqBjNrV4JUxeujrNDy r7A2Q801JMqweIrthIkFN3sOJ8OADsHc5kBypgrwgAymKLEZ50q/CN0mQUhFdB0hqtYc6 9k62HbP45fkiuLDPHNANAgEy3UJxoPswZ8uvJ+ieq67xtJ8NJxPCicPb1JWzSerxDvH53 Rw+r9FYJFdOIgUG3RB8RRqPyfvTt1dZzZnyvM8fzw7uXjtshfnUiIgRoR+Zu5XlAWWA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793283391; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Gm-Gg:X-Received:Received: Received:Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:Content-Transfer-Encoding: In-Reply-To; bh=v0w3vTM41MmYY5jFFnm91zARv8a41r8bbrucc1w3RPo=; b=QQzT6V1GsaLv6vnMdl+Q6Ee2keiOcyih0D98VOoa4xEh53YiD6SMERc521N9oTpO5w8H P3AxyCJbk7z3qgs4WprA1f6SMR3cCB2vMSaicHrHjZpzhaFiws2nJ+W5/dClTDhImyJ2g No3CtDZG3gX3qau811Iv9d3sugCD4OuXrMLzt4zLRoVeG24phGGVi21ZumXASnyt4WHMY 4JwzccxeweI6CaOnAPzfQ+SDgBgniVEcws8cjoS7QFyVEa/iFrFIbdev/Dt2M6YkEh/wp Re1P5EBOwpjT72SPzQFTRJTTjVxIRs/Cju2CHzQzkQBbO0SCPc50w2fr/C0FdmmnmXQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none header.from=ziepe.ca; spf=pass smtp.mailfrom=ziepe.ca; dkim=pass header.d=ziepe.ca header.i=@ziepe.ca header.a=rsa-sha256 header.s=google header.b=K3GWWvW6; arc=none smtp.remote-ip=209.85.160.179 Received: from mail-qt1-f179.google.com (mail-qt1-f179.google.com [209.85.160.179]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 51A3D606A31E for ; Thu, 29 Oct 2026 14:16:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 51A3D606A31E Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ziepe.ca Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ziepe.ca Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=ziepe.ca header.i=@ziepe.ca header.a=rsa-sha256 header.s=google header.b=K3GWWvW6 Received: by mail-qt1-f179.google.com with SMTP id d75a77b69052e-536c8f958d7so18363351cf.1 for ; Thu, 29 Oct 2026 07:16:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; t=1793283390; x=1793888190; darn=vger.kernel.org; h=in-reply-to:content-transfer-encoding:content-disposition :content-type:mime-version:references:message-id:subject:cc:to:from :date:from:to:cc:subject:date:message-id:reply-to:content-type; bh=v0w3vTM41MmYY5jFFnm91zARv8a41r8bbrucc1w3RPo=; b=K3GWWvW6rB7cRoFkVogJ2KSZo/0Y/1HCDIRdHzAIwLoLDsyMicRGMjOseGev/J/xTf 7GktCCuPItsgUn+ypTk60UX0aWoLaz29rDEd+7ry0VKQZgmxJu4rxk9u/82PZO0lHBoj a0rS4Qcv1UTo0qCGsLn097FMzPIIosJ6Sq/dM+Cpe88Ee5HToav+cCJFoWYUIenfBqwj BfXtQt8E5/J+XaBz+AzHqXbj9Vz+xQWJJQPIA+hvJei/SyQf96CW2nSLK1ee/Y9r1bUI sgaZ8c4K2r7GTls+1UpYG7HJCNHiY8m5qhHnc/SvL5F1gGTyDMBNiM4S9pBh3H/k7bQZ gG+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1793283390; x=1793888190; h=in-reply-to:content-transfer-encoding:content-disposition :content-type:mime-version:references:message-id:subject:cc:to:from :date:x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to:content-type; bh=v0w3vTM41MmYY5jFFnm91zARv8a41r8bbrucc1w3RPo=; b=chNujtbtD84MhiAxn4vFBQKOiDvCrk9tw5Ad6yqA7gIBYBlNbft/uf97m2voLHGTaw ySjDmaJbr4gxvxjjuQpel5hjSZ2GiVvfwj9XK0pCmQKSRtd7XoW+kaJC0NCmIVX3qXED pF1VHTWyHTGNEFv0QSK0DqA36IBtRJZejW9T3t7IUaqNzfOK8IObQQNgN0mdOxt4Ug8u dLVKMbe/wRb2CJ0mgu9jyBsP2LI5m+lbB5Nua5lKQ0s3VIm+By8hDkGdw8ZW3JHMwQn/ 86+dg4jEBZp9/k1k4I7HWoKyzqN7oW1t7XdE/w3ICJci93V0VNjvQ6YnvLqi0T21oP1P 7aDg== X-Forwarded-Encrypted: i=1; AKwUvBzuovK2JtGrweaVw+76K9w4w8Mh1Zcd4WRqHEtkwB16TyBY8g7uWhioKLzkMbdgW4KUS/FpX7Fc8i4=@vger.kernel.org X-Gm-Message-State: AFq9FYI8qoRwFl/Brv0Xnp1QieAVwnPMz0pIugjzOPraYROPacTJnwb4 COBMpgYQKHQPODux7GQhVzbvYqXtuIGCr4wHc8GullGgjM82x+wKHJgYPR4aHvjzxLA= X-Gm-Gg: AYBFou237Og44GNaiunK/t3yt0cQbJRNRXgsRWrNyjulLF2BjZkGlRtRoOAU6DD1ThZ J/y/eHaYX4f898nictA9XW2raggLTpSqNx9+3LnErHjESvnW00mCdvXpd7rdLFXaypPT3ToFSfF 0q7dVupCqBlFRIQIvdYhW38x/191YH8LUb1ecoJm1laypie32z9Lmkymjqqz7xmGoou+HkctS7s aB1EjJmc6pLQdsKpeT4qEBb7zf0N0LdGrV1H5leUQPR0x9NDvFWr6Yc5PBlYotFjtkmV63KSVmO 3E6CLAm23yzTPzG1ZhLUxVz6PF9riTurOa9e/Ng8E6ekfputbkPZNn993NbvVOn7iQkTopqeI62 jIAukIxzqklZBYf8roMZdJYnxTxupZJXB1G+DIyFQaoy4kpAdBN9a1muPVXykCjB/dWM7SbKScX PSPVjXdHqczElLxrst+FwfYkQIPDqCWXYWOmjVvc5V0IUwxZy2R7YvD6sq6bNF22PRr1lXFC8Um ct6MbktXtSHRFIoW6q5anlo4t1tG8WkE1FKaU5hqAFKrUy1sB/hvfDQSGhLw62pP9X4f8vuF5N+ TE8or5xGaDtGqgJKB32/3nhKRtfPCfciLQak93INFZNklAuyr8cCFsarGJmdip/EDEI9q/llTWN lZrSEVNxOpUw= X-Received: by 2002:a05:622a:5c14:b0:533:21c6:f4e2 with SMTP id d75a77b69052e-53fcb20dda0mr85167991cf.20.1793283389957; Thu, 29 Oct 2026 07:16:29 -0700 (PDT) Received: from ziepe.ca (hlfxns010zw-159-2-239-150.pppoe-dynamic.high-speed.ns.bellaliant.net. [159.2.239.150]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-91c7f6ef1b7sm45505406d6.7.2026.10.29.07.16.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 29 Oct 2026 07:16:29 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1xMQvb-0000000FihF-2QML; Thu, 29 Oct 2026 11:16:27 -0300 Date: Thu, 29 Oct 2026 11:16:27 -0300 From: Jason Gunthorpe To: Nikolay Borisov Cc: Jiri Pirko , linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, david.quigley@intel.com, lukas@wunner.de, ksinyuk@kernel.org, rodrigo.vivi@intel.com, cedric.xing@intel.com, sameo@meta.com, drdeeglaze@gmail.com, James.Bottomley@hansenpartnership.com, aik@amd.com, jpiotrowski@nvidia.com, qinkun@google.com, pgonda@google.com, jic23@kernel.org, alistair.francis@wdc.com, ankita@nvidia.com, suzuki.poulose@arm.com, kas@kernel.org, rick.p.edgecombe@intel.com, elena.reshetova@intel.com, dave.hansen@linux.intel.com, sathyanarayanan.kuppuswamy@linux.intel.com, peter.fang@intel.com Subject: Re: [PATCH RFC 00/20] attestation: Add a common subsystem and TDX support Message-ID: <20261029141627.GP1685504@ziepe.ca> References: <20261015145053.3664509-1-jiri@resnulli.us> <2a2a5d93-1c10-4533-8709-437ceb6a3f94@suse.com> X-Mailing-List: linux-doc@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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <2a2a5d93-1c10-4533-8709-437ceb6a3f94@suse.com> On Thu, Oct 29, 2026 at 09:37:20AM +0200, Nikolay Borisov wrote: > > > On 15.10.26 г. 17:50 ч., Jiri Pirko wrote: > > From: Jiri Pirko > > > > Linux has several attestation interfaces tied to individual technologies. > > That makes evidence retrieval, measurement registers, device state and > > kernel consumers provider-specific. > > > > This series introduces a common attestation subsystem. Its goal is to > > support platform, TEE and device providers through one model, including > > TPM2, TDX, SEV-SNP, Arm CCA, FIRME, Caliptra and PCI/TSM-backed devices. > > This first series implements the common subsystem and a TDX provider. > > Existing native TDX tsm_mr and tsm_report interfaces remain independent. > > Wasn't config-tsm supposed to be this common attestation subsystem? Was this > discussed when the initial config-tsm was proposed? Why is this coming now? Maybe but it was far too narrowly scoped to do that. config-tsm doesn't even include MRs, they were awkwardly pushed off into another different spot. It just doesn't seem to meet the need, and it can't sanely fit SPDM. > > Attestation devices use CTLV, a schema-driven character-device TLV UAPI. > > Compared with sysfs or configfs, CTLV executes one validated request > > atomically instead of assembling a transaction through several files. > > Compared with netlink, an opened device fd directly identifies authority > > and lifetime, can be delegated normally, and owns its event queue. CTLV > > also provides: > > Assuming we want to go through the route of CTLV, do we really want an > attestation-specific interface, or most of this functionality can > simply be CTLV is not attestation specific.. > implemented as a specific genetlink protocol, utilising all the existing > hardening that has gone into netlink's infrastructure to marshal messages > from userspace to kernel space? Been there, seems like a hard no: https://lore.kernel.org/all/20260721182046.16219426@kernel.org/ And then later this: https://lore.kernel.org/all/20260921131911.532d81f4@kernel.org/ Plus netlink being based around sockets and net namespaces is a very poor fit for something that has nothing to do with net namespaces and really wants a DAC security model. > > 83 files changed, 18084 insertions(+), 28 deletions(-) > > That's an awful lot of code to just move certain binary blobs around > (Judging by what config-tsm is doing ATM). Yeah, netlink is alot of code. ctlv is trying to solve a bigger more general problem than just config-tsm. Attestation is simply the first user as it has some complicated data structure that suits it well. Jason