Refactor OP-TEE message types and add RPC args support by sangho2 · Pull Request #664 · microsoft/litebox

sangho2 · 2026-02-13T03:27:09Z

This PR refactors the OP-TEE message types and related functions to handle variable-length parameters. It also supports OP-TEE RPC message types to enable future RPC implementation. In addition, it leverages zerocopy to remove some unsafe operations.

#641

wdcui

Overall the code looks good to me. I left some minor comments below.

wdcui · 2026-02-13T18:24:38Z

litebox_common_optee/src/lib.rs

-    }
-}
-pub use workaround_identity_op_suppression::UteeParamsTypes;
+/// Number of RPC parameters that LiteBox defined and reported to the normal-world


Nit: LiteBox -> the OPTEE shim?

litebox_common_optee/src/lib.rs

wdcui · 2026-02-13T18:28:21Z

litebox_common_optee/src/lib.rs

+
+/// `OPTEE_MSG_RPC_CMD_*` from `optee_os/core/include/optee_msg.h`
+///
+/// These are the command IDs used in the `cmd` field of the RPC `optee_msg_arg`.


The comment here overlaps quite a bit with the comment above?

let me merge them

wdcui · 2026-02-13T18:30:36Z

litebox_common_optee/src/lib.rs

+impl OpteeMsgAttr {
+    /// Returns the attribute type (bits 0–7).
+    #[allow(clippy::cast_possible_truncation)]
+    pub fn typ(&self) -> u8 {


OPTEE calls this typ instead of type?

OP-TEE calls it type but type is a reserved keyword in Rust.

Can we use a longer name like "xxx_type"?

attr_type?

wdcui · 2026-02-13T18:36:23Z

litebox_common_optee/src/lib.rs

+    /// Maximum number of parameters that `OpteeMsgArgs` can hold.
+    ///
+    /// This is `TEE_NUM_PARAMS + 2` = 6, matching the Linux driver's `MAX_ARG_PARAM_COUNT`.
+    pub const MAX_PARAMS: usize = TEE_NUM_PARAMS + 2;


NIT: MAX_PARAMS is public and sounds very general. Maybe TEE_MAX_NUMBER_PARAME`?

This is a member constant of OpteeMsgArgs. Can rename it if it looks too general.

It may help to make the name more specific.

MAX_ARG_PARAM_COUNT? This is what OP-TEE driver is using.

wdcui · 2026-02-13T18:41:20Z

litebox_common_optee/src/lib.rs

+    /// Maximum number of RPC parameters this struct can hold.
+    ///
+    /// This is [`NUM_RPC_PARAMS`], the count negotiated during `EXCHANGE_CAPABILITIES`.
+    pub const MAX_PARAMS: usize = NUM_RPC_PARAMS;


Another MAX_PARAMS?

same. this is a member constant of OpteeRpcArgs.

wdcui · 2026-02-13T18:42:53Z

litebox_common_optee/src/lib.rs

+        if num > Self::MAX_PARAMS {
+            return Err(OpteeSmcReturnCode::EBadCmd);
+        }
+        let needed = num * size_of::<OpteeMsgParam>();


Do we need to include the header size here?

This variable checks whether the length of new_params is enough to store parameters. Let me rename the variable name.

wdcui · 2026-02-13T18:51:03Z

litebox_shim_optee/src/msg_handler.rs

+    // Compute copy size from known-good upper bounds — no untrusted data involved.
+    let main_max = optee_msg_arg_total_size(OpteeMsgArgs::MAX_PARAMS.truncate());
+    let copy_size = if has_rpc_arg {
+        main_max + optee_msg_arg_total_size(NUM_RPC_PARAMS.truncate())


why do use NUM_RPC_PARAMS here instead of MAX_PARAMS?

Let me use OpteeRpcArgs::MAX_PARAMS instead of NUM_RPC_PARAMS.

github-actions · 2026-02-13T23:25:03Z

🤖 SemverChecks 🤖 ⚠️ Potential breaking API changes detected ⚠️

Click for details

--- failure enum_struct_variant_field_added: pub enum struct variant field added ---

Description:
An enum's exhaustive struct variant has a new field, which has to be included when constructing or matching on this variant.
        ref: https://doc.rust-lang.org/reference/attributes/type_system.html#the-non_exhaustive-attribute
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.46.0/src/lints/enum_struct_variant_field_added.ron

Failed in:
  field rpc_args of variant OpteeSmcResult::CallWithArg in /home/runner/work/litebox/litebox/litebox_common_optee/src/lib.rs:2060

--- failure inherent_method_missing: pub method removed or renamed ---

Description:
A publicly-visible method or associated fn is no longer available under its prior name. It may have been renamed or removed entirely.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#item-remove
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.46.0/src/lints/inherent_method_missing.ron

Failed in:
  UteeParamsTypes::new, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:415
  UteeParamsTypes::into_bytes, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:415
  UteeParamsTypes::from_bytes, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:415
  UteeParamsTypes::type_0_or_err, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:418
  UteeParamsTypes::with_type_0, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:418
  UteeParamsTypes::with_type_0_checked, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:418
  UteeParamsTypes::set_type_0_checked, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:418
  UteeParamsTypes::type_1_or_err, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:419
  UteeParamsTypes::with_type_1, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:419
  UteeParamsTypes::with_type_1_checked, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:419
  UteeParamsTypes::set_type_1_checked, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:419
  UteeParamsTypes::type_2_or_err, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:420
  UteeParamsTypes::with_type_2, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:420
  UteeParamsTypes::with_type_2_checked, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:420
  UteeParamsTypes::set_type_2_checked, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:420
  UteeParamsTypes::type_3_or_err, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:421
  UteeParamsTypes::with_type_3, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:421
  UteeParamsTypes::with_type_3_checked, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:421
  UteeParamsTypes::set_type_3_checked, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:421
  OpteeMsgAttr::new, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1348
  OpteeMsgAttr::into_bytes, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1348
  OpteeMsgAttr::from_bytes, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1348
  OpteeMsgAttr::typ, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1353
  OpteeMsgAttr::typ_or_err, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1353
  OpteeMsgAttr::with_typ, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1353
  OpteeMsgAttr::with_typ_checked, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1353
  OpteeMsgAttr::set_typ, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1353
  OpteeMsgAttr::set_typ_checked, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1353
  OpteeMsgAttr::meta_or_err, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1354
  OpteeMsgAttr::with_meta, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1354
  OpteeMsgAttr::with_meta_checked, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1354
  OpteeMsgAttr::set_meta, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1354
  OpteeMsgAttr::set_meta_checked, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1354
  OpteeMsgAttr::noncontig_or_err, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1355
  OpteeMsgAttr::with_noncontig, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1355
  OpteeMsgAttr::with_noncontig_checked, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1355
  OpteeMsgAttr::set_noncontig, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1355
  OpteeMsgAttr::set_noncontig_checked, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1355

--- failure repr_c_removed: repr(C) removed ---

Description:
repr(C) was removed from a type. This can cause its memory layout to change, breaking FFI use cases.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#repr-c-remove
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.46.0/src/lints/repr_c_removed.ron

Failed in:
  struct UteeParamsTypes in /home/runner/work/litebox/litebox/litebox_common_optee/src/lib.rs:422
  struct OpteeMsgAttr in /home/runner/work/litebox/litebox/litebox_common_optee/src/lib.rs:1429

--- failure union_missing: pub union removed or renamed ---

Description:
A publicly-visible union cannot be imported by its prior path. A `pub use` may have been removed, or the union itself may have been renamed or removed entirely.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#item-remove
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.46.0/src/lints/union_missing.ron

Failed in:
  union litebox_common_optee::OpteeMsgParamUnion, previously in file /home/runner/work/litebox/litebox/target/semver-checks/git-main/aa028baa08c98942826f673ebeb18e6d6f5baf6d/litebox_common_optee/src/lib.rs:1311

Sangho Lee added 5 commits February 12, 2026 22:21

Add OpteeMsgArgsHeader to deal with optional RPC args

e6d1c4a

OpteeRpcArgs and other improvements

1dc9716

zerocopy to further remove unsafe

5cd5d8d

clippy

2effbc3

refactoring

fe955fc

sangho2 marked this pull request as ready for review February 13, 2026 03:32

Non TA MsgArgs

e2e91e2

sangho2 force-pushed the sanghle/optee/msgs_v2 branch from 275c28f to e2e91e2 Compare February 13, 2026 05:07

wdcui approved these changes Feb 13, 2026

View reviewed changes

addressed feedbacks

28d0a36

sangho2 force-pushed the sanghle/optee/msgs_v2 branch from 002a576 to 28d0a36 Compare February 13, 2026 23:17

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sangho2 commented Feb 13, 2026 •

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