On 8/19/24 11:19 PM, Steven Price wrote:
From: Sami Mujawar <sami.mujawar@xxxxxxx>
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@xxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Signed-off-by: Steven Price <steven.price@xxxxxxx>
---
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
