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From: Dan Williams <dan.j.williams@intel.com>
To: Steven Price <steven.price@arm.com>, <kvm@vger.kernel.org>,
	<kvmarm@lists.linux.dev>
Cc: Sami Mujawar <sami.mujawar@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Marc Zyngier <maz@kernel.org>, Will Deacon <will@kernel.org>,
	James Morse <james.morse@arm.com>,
	Oliver Upton <oliver.upton@linux.dev>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	"Zenghui Yu" <yuzenghui@huawei.com>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>, Joey Gouly <joey.gouly@arm.com>,
	"Alexandru Elisei" <alexandru.elisei@arm.com>,
	Christoffer Dall <christoffer.dall@arm.com>,
	Fuad Tabba <tabba@google.com>, <linux-coco@lists.linux.dev>,
	Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>,
	Gavin Shan <gshan@redhat.com>,
	"Shanker Donthineni" <sdonthineni@nvidia.com>,
	Alper Gun <alpergun@google.com>,
	"Dan Williams" <dan.j.williams@intel.com>,
	"Aneesh Kumar K . V" <aneesh.kumar@kernel.org>,
	Steven Price <steven.price@arm.com>
Subject: Re: [PATCH v7 10/11] virt: arm-cca-guest: TSM_REPORT support for realms
Date: Wed, 4 Dec 2024 13:16:05 -0800	[thread overview]
Message-ID: <6750c695194cd_2508129427@dwillia2-xfh.jf.intel.com.notmuch> (raw)
In-Reply-To: <20241017131434.40935-11-steven.price@arm.com>

Steven Price wrote:
> From: Sami Mujawar <sami.mujawar@arm.com>
> 
> Introduce an arm-cca-guest driver that registers with
> the configfs-tsm module to provide user interfaces for
> retrieving an attestation token.
> 
> When a new report is requested the arm-cca-guest driver
> invokes the appropriate RSI interfaces to query an
> attestation token.
> 
> The steps to retrieve an attestation token are as follows:
>   1. Mount the configfs filesystem if not already mounted
>      mount -t configfs none /sys/kernel/config
>   2. Generate an attestation token
>      report=/sys/kernel/config/tsm/report/report0
>      mkdir $report
>      dd if=/dev/urandom bs=64 count=1 > $report/inblob
>      hexdump -C $report/outblob
>      rmdir $report
> 
> Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> Signed-off-by: Steven Price <steven.price@arm.com>
> ---
> Changes since v6:
>  * Avoid get_cpu() and instead make the init attestation call using
>    smp_call_function_single(). Improve comments to explain the logic.
>  * Minor code reorgnisation and comment cleanup following Gavin's review
>    (thanks!)
> ---
>  drivers/virt/coco/Kconfig                     |   2 +
>  drivers/virt/coco/Makefile                    |   1 +
>  drivers/virt/coco/arm-cca-guest/Kconfig       |  11 +
>  drivers/virt/coco/arm-cca-guest/Makefile      |   2 +
>  .../virt/coco/arm-cca-guest/arm-cca-guest.c   | 224 ++++++++++++++++++
>  5 files changed, 240 insertions(+)
>  create mode 100644 drivers/virt/coco/arm-cca-guest/Kconfig
>  create mode 100644 drivers/virt/coco/arm-cca-guest/Makefile
>  create mode 100644 drivers/virt/coco/arm-cca-guest/arm-cca-guest.c
[..]
> diff --git a/drivers/virt/coco/arm-cca-guest/Kconfig b/drivers/virt/coco/arm-cca-guest/Kconfig
> new file mode 100644
> index 000000000000..9dd27c3ee215
> --- /dev/null
> +++ b/drivers/virt/coco/arm-cca-guest/Kconfig
> @@ -0,0 +1,11 @@
> +config ARM_CCA_GUEST
> +	tristate "Arm CCA Guest driver"
> +	depends on ARM64
> +	default m

I am working on some updates to the TSM_REPORTS interface, rebased them
to test the changes with this driver, and discovered that this driver is
enabled by default.

Just a reminder to please do not mark new drivers as "default m" [1]. In
this case it is difficult to imagine that every arm64 kernel on the
planet needs this functionality enabled by default. In general, someone
should be able to run olddefconfig with a new kernel and not be exposed
to brand new drivers that they have not considered previously.

[1]: http://lore.kernel.org/CA+55aFzxL6-Xp=-mnBwMisZsuKhRZ6zRDJoAmH8W5LDHU2oJuw@mail.gmail.com/


  parent reply	other threads:[~2024-12-04 21:17 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20241017131434.40935-1-steven.price@arm.com>
2024-10-23 10:02 ` [PATCH v7 00/11] arm64: Support for running as a guest in Arm CCA Catalin Marinas
     [not found] ` <20241017131434.40935-11-steven.price@arm.com>
2024-12-04 21:16   ` Dan Williams [this message]
2024-12-05 11:51     ` [PATCH v7 10/11] virt: arm-cca-guest: TSM_REPORT support for realms Catalin Marinas
     [not found] ` <20241017131434.40935-10-steven.price@arm.com>
2025-02-19 14:30   ` [PATCH v7 09/11] arm64: Enable memory encrypt for Realms Steven Price
2025-02-26 19:03     ` Catalin Marinas
2025-02-27  0:23       ` Will Deacon
2025-02-27 10:45         ` Steven Price
2025-02-27 10:55         ` Catalin Marinas
2025-02-27 17:22           ` Will Deacon
2025-02-27 21:21             ` Catalin Marinas

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