Re: [PATCH v5 19/19] virt: arm-cca-guest: TSM_REPORT support for realms

[Gavin Shan <gshan@redhat.com>]

On 8/19/24 11:19 PM, 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>
> ---
> v3: Minor improvements to comments and adapt to the renaming of
> GRANULE_SIZE to RSI_GRANULE_SIZE.
> ---
>   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   | 211 ++++++++++++++++++
>   5 files changed, 227 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
> 

[...]

> +
> +/**
> + * 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. Allocate memory for the attestation token
                         ^^^^^^^^^

Typo. s/decriptor/descriptor as reported by './scripts/checkpatch.pl --codespell'


> + * and schedule calls to retrieve the attestation token on the same CPU
> + * on which the attestation token generation was initialised.
> + *
> + * The challenge data must be at least 32 bytes and no more than 64 bytes. If
> + * less than 64 bytes are provided it will be zero padded to 64 bytes.
> + *
> + * Return:
> + * * %0        - Attestation token generated successfully.
> + * * %-EINVAL  - A parameter was not valid.
> + * * %-ENOMEM  - Out of memory.
> + * * %-EFAULT  - Failed to get IPA for memory page(s).
> + * * A negative status code as returned by smp_call_function_single().
> + */

Thanks,
Gavin