[PATCH v4 0/9] Add RISC-V Worlds ISA support to OpenSBI

[Yu-Chien Peter Lin <peter.lin@sifive.com>]

This patch series adds support for the RISC-V Worlds ISA extensions in
OpenSBI, introducing a WID-based hart protection backend to enforce
hardware isolation boundaries across domains.

Trust Model and Boot-time Roles
-------------------------------

The implementation adheres to the two-phase M-mode trust model:

- RoT M-mode phase: An earlier boot stage (e.g., ROM or SPL) may program
  mwid and mlwidlist, locking mwid prior to handing off execution to
  OpenSBI.

- Regular M-mode phase (OpenSBI): OpenSBI treats the non-ISA platform
  constraints (pmwid, pmwidlist, pmlwidlist) and CSR states (mwid,
  mlwidlist) as immutable input policies from the hardware/RoT. It locks
  mwid if still unlocked, preventing subsequent M-mode software from
  altering its own WID, and programs per-domain mlwid and mwiddeleg based
  on device tree configuration.

Device Tree Bindings
--------------------

Per-hart properties defined in Linux kernel DT bindings v3 [1]:
- riscv,pmwid: M-mode World ID
- riscv,pmwidlist: M-mode permitted WID bitmap
- riscv,pmlwidlist: S/U-mode permitted WID bitmap

Per-domain properties (see docs/domain_support.md):
- wid: World ID assigned to this domain for S/U-mode
- widdeleg: WID delegation bitmap for this domain

[1] https://patchwork.kernel.org/project/linux-riscv/cover/20260812122131.1534906-1-peter.lin@sifive.com/

Yu-Chien Peter Lin (9):
  lib: sbi_hart: add RISC-V Worlds ISA extensions
  lib: utils: fdt_helper: parse RISC-V Worlds per-hart WID properties
  lib: fdt_domain: parse domain WID properties
  lib: sbi_hart: lock mwid CSR for RoT immutability
  lib: sbi_domain_context: propagate error from
    sbi_hart_protection_reconfigure
  lib: sbi_hart_worlds: Implement WID hart protection backend
  include: sbi_types: add PRIx64 format macro
  lib: sbi: display World ID configuration at boot
  docs: document WID DT properties

 docs/domain_support.md        |  38 ++++++
 include/sbi/riscv_encoding.h  |  12 ++
 include/sbi/sbi_domain.h      |   6 +
 include/sbi/sbi_hart.h        |  15 +++
 include/sbi/sbi_hart_worlds.h |  24 ++++
 include/sbi/sbi_types.h       |   2 +
 lib/sbi/objects.mk            |   1 +
 lib/sbi/sbi_domain.c          |  20 ++++
 lib/sbi/sbi_domain_context.c  |   5 +-
 lib/sbi/sbi_hart.c            |  17 +++
 lib/sbi/sbi_hart_worlds.c     | 210 ++++++++++++++++++++++++++++++++++
 lib/sbi/sbi_init.c            |  13 +++
 lib/utils/fdt/fdt_domain.c    |  87 ++++++++++++++
 lib/utils/fdt/fdt_helper.c    |  69 +++++++++--
 14 files changed, 511 insertions(+), 8 deletions(-)
 create mode 100644 include/sbi/sbi_hart_worlds.h
 create mode 100644 lib/sbi/sbi_hart_worlds.c

-- 
2.43.7


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