[PATCH 0/3] arm64: realm: Add support for encrypted data from firmware

Suzuki K Poulose suzuki.poulose at arm.com
Fri Jun 13 04:11:50 PDT 2025


Confidential compute firmware may provide secret data via reserved memory regions
(e.g., ACPI CCEL, EFI Coco secret area). These must be ioremap'ed() as encrypted.
As of now, realm only maps "trusted devices" (RIPAS = RSI_RIPAS_DEV) as encrypted.
This series adds support for mapping areas that are protected
(i.e., RIPAS = RSI_RIPAS_RAM) as encrypted. Also, extrapolating that, we can map
anything that is not RIPAS_EMPTY as protected, as it is guaranteed to be "protected".

With this in place, we can naturally map any firmware provided area based on the
RIPAS value. If the firmware provides a shared region (not trusted), it must have
set the RIPAS accordingly, before placing the data, as the transition is always
destructive.

Also enables the EFI Coco secret area support and Confidential Compute Event
Log (CCEL) for arm64.


Suzuki K Poulose (3):
  arm64: realm: ioremap: Allow mapping memory as encrypted
  arm64: Enable EFI secret area Securityfs support
  arm64: acpi: Enable ACPI CCEL support

 arch/arm64/include/asm/io.h          |  6 +++++-
 arch/arm64/include/asm/rsi.h         |  2 +-
 arch/arm64/kernel/acpi.c             |  5 +++++
 arch/arm64/kernel/rsi.c              | 26 ++++++++++++++++++++++----
 drivers/virt/coco/efi_secret/Kconfig |  2 +-
 5 files changed, 34 insertions(+), 7 deletions(-)

-- 
2.43.0




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