From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Dan Williams <dan.j.williams@intel.com>
Cc: linux-coco@lists.linux.dev,
Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@linux.intel.com>,
Dionna Amalie Glaze <dionnaglaze@google.com>,
James Bottomley <James.Bottomley@hansenpartnership.com>,
Peter Gonda <pgonda@google.com>,
Samuel Ortiz <sameo@rivosinc.com>,
peterz@infradead.org, linux-kernel@vger.kernel.org,
tglx@linutronix.de
Subject: Re: [PATCH v3 2/5] configfs-tsm: Introduce a shared ABI for attestation reports
Date: Wed, 30 Aug 2023 22:45:52 +0200 [thread overview]
Message-ID: <2023083029-wackiness-lilac-39dd@gregkh> (raw)
In-Reply-To: <169342400469.3934343.12316161608372095860.stgit@dwillia2-xfh.jf.intel.com>
On Wed, Aug 30, 2023 at 12:33:24PM -0700, Dan Williams wrote:
> One of the common operations of a TSM (Trusted Security Module) is to
> provide a way for a TVM (confidential computing guest execution
> environment) to take a measurement of its launch state, sign it and
> submit it to a verifying party. Upon successful attestation that
> verifies the integrity of the TVM additional secrets may be deployed.
> The concept is common across TSMs, but the implementations are
> unfortunately vendor specific. While the industry grapples with a common
> definition of this attestation format [1], Linux need not make this
> problem worse by defining a new ABI per TSM that wants to perform a
> similar operation. The current momentum has been to invent new ioctl-ABI
> per TSM per function which at best is an abdication of the kernel's
> responsibility to make common infrastructure concepts share common ABI.
>
> The proposal, targeted to conceptually work with TDX, SEV-SNP, COVE if
> not more, is to define a configfs interface to retrieve the TSM-specific
> blob.
>
> report=/sys/kernel/config/tsm/report/report0
> mkdir $report
> dd if=binary_userdata_plus_nonce > $report/inblob
> hexdump $report/outblob
>
> This approach later allows for the standardization of the attestation
> blob format without needing to invent a new ABI. Once standardization
> happens the standard format can be emitted by $report/outblob and
> indicated by $report/provider, or a new attribute like
> "$report/tcg_coco_report" can emit the standard format alongside the
> vendor format.
>
> Review of previous iterations of this interface identified that there is
> a need to scale report generation for multiple container environments
> [2]. Configfs enables a model where each container can bind mount one or
> more report generation item instances. Still, within a container only a
> single thread can be manipulating a given configuration instance at a
> time. A 'generation' count is provided to detect conflicts between
> multiple threads racing to configure a report instance.
>
> The SEV-SNP concepts of "extended reports" and "privilege levels" are
> optionally enabled by selecting 'tsm_report_ext_type' at register_tsm()
> time. The expectation is that those concepts are generic enough that
> they may be adopted by other TSM implementations. In other words,
> configfs-tsm aims to address a superset of TSM specific functionality
> with a common ABI where attributes may appear, or not appear, based on the set
> of concepts the implementation supports.
>
> Link: http://lore.kernel.org/r/64961c3baf8ce_142af829436@dwillia2-xfh.jf.intel.com.notmuch [1]
> Link: http://lore.kernel.org/r/57f3a05e-8fcd-4656-beea-56bb8365ae64@linux.microsoft.com [2]
> Cc: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
> Cc: Dionna Amalie Glaze <dionnaglaze@google.com>
> Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
> Cc: Peter Gonda <pgonda@google.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Samuel Ortiz <sameo@rivosinc.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
> Documentation/ABI/testing/configfs-tsm | 68 ++++++
Nice, I like the use of configfs here.
One very tiny naming nit, feel free to ignore if you don't want to
change it:
> +int register_tsm(const struct tsm_ops *ops, void *priv,
> + const struct config_item_type *type);
> +int unregister_tsm(const struct tsm_ops *ops);
Usually it's "noun_verb" for stuff that you export to the global
namespace these days.
So perhaps tsm_register() and tsm_unregister()?
Either way, it's your call:
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
next prev parent reply other threads:[~2023-08-30 21:52 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-30 19:33 [PATCH v3 0/5] configfs-tsm: Attestation Report ABI Dan Williams
2023-08-30 19:33 ` [PATCH v3 1/5] virt: coco: Add a coco/Makefile and coco/Kconfig Dan Williams
2023-08-30 20:48 ` Kuppuswamy Sathyanarayanan
2023-08-30 19:33 ` [PATCH v3 2/5] configfs-tsm: Introduce a shared ABI for attestation reports Dan Williams
2023-08-30 20:45 ` Greg Kroah-Hartman [this message]
2023-08-30 20:57 ` Dan Williams
2023-08-30 22:08 ` Kuppuswamy Sathyanarayanan
2023-08-31 1:24 ` Dan Williams
2023-08-31 21:42 ` Dionna Amalie Glaze
2023-08-31 22:13 ` Dan Williams
2023-09-01 18:06 ` Thomas Gleixner
2023-09-01 18:47 ` Dan Williams
2023-09-01 19:06 ` Thomas Gleixner
2023-08-30 19:33 ` [PATCH v3 3/5] virt: sevguest: Prep for kernel internal {get, get_ext}_report() Dan Williams
2023-08-30 19:33 ` [PATCH v3 4/5] mm/slab: Add __free() support for kvfree Dan Williams
2023-08-30 20:46 ` Greg Kroah-Hartman
2023-09-07 8:59 ` Gupta, Pankaj
2023-08-30 19:33 ` [PATCH v3 5/5] virt: sevguest: Add TSM_REPORTS support for SNP_{GET, GET_EXT}_REPORT Dan Williams
2023-09-01 15:25 ` Jeremi Piotrowski
2023-09-01 16:38 ` Dan Williams
2023-09-04 2:14 ` Huang, Kai
2023-09-04 2:57 ` Kuppuswamy Sathyanarayanan
2023-09-05 23:21 ` Huang, Kai
2023-09-01 16:04 ` [PATCH v3 0/5] configfs-tsm: Attestation Report ABI Jeremi Piotrowski
2023-09-01 16:51 ` Dan Williams
2023-09-07 8:04 ` Samuel Ortiz
2023-09-25 19:26 ` Dan Williams
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