platform/tdp: replace tdx-tdcall crate with local implementation

The `tdx-tdcall` crate is built for different security and design
assumptions than what is required for COCONUT-SVSM.  The TDCALL/TDVMCALL
functionality required can be implemented locally, providing better
integration with the COCONUT-SVSM environment.

Signed-off-by: Jon Lange <[email protected]>

Cargo.toml

@@ -42,7 +42,6 @@ libfuzzer-sys = "0.4"
 log = "0.4.17"
 p384 = { version = "0.13.0" }
 sha2 = "0.10.8"
-tdx-tdcall = "0.2.1"
 uuid = "1.6.1"
 # Add the derive feature by default because all crates use it.
 zerocopy = { version = "0.8.2", features = ["alloc", "derive"] }

kernel/Cargo.toml

@@ -33,7 +33,6 @@ igvm_defs = { workspace = true, features = ["unstable"] }
 intrusive-collections.workspace = true
 log = { workspace = true, features = ["max_level_info", "release_max_level_info"] }
 packit.workspace = true
-tdx-tdcall.workspace = true
 libmstpm = { workspace = true, optional = true }
 zerocopy.workspace = true
 

kernel/src/error.rs

@@ -27,6 +27,7 @@ use crate::sev::msr_protocol::GhcbMsrError;
 use crate::sev::SevSnpError;
 use crate::syscall::ObjError;
 use crate::task::TaskError;
+use crate::tdx::TdxError;
 use elf::ElfError;
 use syscall::SysCallError;
 
@@ -58,7 +59,7 @@ pub enum SvsmError {
     /// Errors related to SEV-SNP operations, like PVALIDATE or RMPUPDATE
     SevSnp(SevSnpError),
     /// Errors related to TDX operations
-    Tdx,
+    Tdx(TdxError),
     /// Generic errors related to memory management
     Mem,
     /// Errors related to the memory allocator

kernel/src/lib.rs

@@ -37,6 +37,7 @@ pub mod string;
 pub mod svsm_paging;
 pub mod syscall;
 pub mod task;
+pub mod tdx;
 pub mod types;
 pub mod utils;
 #[cfg(all(feature = "mstpm", not(test)))]