Re: [PATCH v7 10/11] virt: arm-cca-guest: TSM_REPORT support for realms

From: Gavin Shan
Date: Tue Oct 22 2024 - 23:29:43 EST


On 10/17/24 11:14 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>
---
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


Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>