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Date: Wed, 24 Apr 2024 14:27:41 +0100
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Subject: Re: [PATCH v2 14/14] virt: arm-cca-guest: TSM_REPORT support for
 realms
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To: Thomas Fossati <thomas.fossati@linaro.org>,
 Steven Price <steven.price@arm.com>
Cc: kvm@vger.kernel.org, kvmarm@lists.linux.dev,
 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>, 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>
References: <20240412084056.1733704-1-steven.price@arm.com>
 <20240412084213.1733764-1-steven.price@arm.com>
 <20240412084213.1733764-15-steven.price@arm.com>
 <CA+1=6ydMVk4Vcouc2ag8G7tfqZy80VWFxWHSHEKF1JaABd=A7A@mail.gmail.com>
From: Suzuki K Poulose <suzuki.poulose@arm.com>
In-Reply-To: <CA+1=6ydMVk4Vcouc2ag8G7tfqZy80VWFxWHSHEKF1JaABd=A7A@mail.gmail.com>
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On 24/04/2024 14:06, Thomas Fossati wrote:
> Hi Steven, Sami,
> 
> On Fri, 12 Apr 2024 at 10:47, Steven Price <steven.price@arm.com> wrote:
>> +/**
>> + * arm_cca_report_new - Generate a new attestation token.
>> + *
>> + * @report: pointer to the TSM report context information.
>> + * @data:  pointer to the context specific data for this module.
>> + *
>> + * Initialise the attestation token generation using the challenge data
>> + * passed in the TSM decriptor.
> 
> Here, it'd be good to document two interesting facts about challenge data:
> 1. It must be at least 32 bytes, and
> 2. If its size is less than 64 bytes, it will be zero-padded.

Agreed !

Suzuki

> 
> cheers!