Re: [PATCH v2 14/14] virt: arm-cca-guest: TSM_REPORT support for realms

From: Suzuki K Poulose
Date: Wed Apr 24 2024 - 09:19:51 EST


On 12/04/2024 09:42, 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>
---
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 | 208 ++++++++++++++++++
5 files changed, 224 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/Kconfig b/drivers/virt/coco/Kconfig
index 87d142c1f932..4fb69804b622 100644
--- a/drivers/virt/coco/Kconfig
+++ b/drivers/virt/coco/Kconfig
@@ -12,3 +12,5 @@ source "drivers/virt/coco/efi_secret/Kconfig"
source "drivers/virt/coco/sev-guest/Kconfig"
source "drivers/virt/coco/tdx-guest/Kconfig"
+
+source "drivers/virt/coco/arm-cca-guest/Kconfig"
diff --git a/drivers/virt/coco/Makefile b/drivers/virt/coco/Makefile
index 18c1aba5edb7..a6228a1bf992 100644
--- a/drivers/virt/coco/Makefile
+++ b/drivers/virt/coco/Makefile
@@ -6,3 +6,4 @@ obj-$(CONFIG_TSM_REPORTS) += tsm.o
obj-$(CONFIG_EFI_SECRET) += efi_secret/
obj-$(CONFIG_SEV_GUEST) += sev-guest/
obj-$(CONFIG_INTEL_TDX_GUEST) += tdx-guest/
+obj-$(CONFIG_ARM_CCA_GUEST) += arm-cca-guest/
diff --git a/drivers/virt/coco/arm-cca-guest/Kconfig b/drivers/virt/coco/arm-cca-guest/Kconfig
new file mode 100644
index 000000000000..c4039c10dce2
--- /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
+ select TSM_REPORTS
+ help
+ The driver provides userspace interface to request and
+ attestation report from the Realm Management Monitor(RMM).
+
+ If you choose 'M' here, this module will be called
+ realm-guest.

This needs to be updated to arm-cca-guest.

Suzuki