// Copyright (c) 2020-2025 Intel Corporation

//

// SPDX-License-Identifier: BSD-2-Clause-Patent

//! Guest-Side (TDCALL) Interface Helper Functions

//!

//! This crate implements the helper functions for the TDCALL interface functions defined in

//! Intel TDX Module specifiction and the TDVMCALL sub-functions defined in Intel TDX

//! Guest-Hypervisor Communication Interface specification. It also provides the constants

//! and data structures that are defined in the specifications.

//!

//! Please refer to following links for detail:

//! [Intel TDX Module v1.0 Spec](https://www.intel.com/content/dam/develop/external/us/en/documents/tdx-module-1.0-public-spec-v0.931.pdf)

//! [Intel TDX Module v1.5 Spec](https://www.intel.com/content/dam/develop/external/us/en/documents/intel-tdx-module-1.5-abi-spec-348551001.pdf)

//! [Intel TDX Guest-Hypervisor Communication Interface Spec](https://cdrdv2.intel.com/v1/dl/getContent/726790)

//! [Intel TDX Guest-Hypervisor Communication Interface Spec v1.5](https://cdrdv2.intel.com/v1/dl/getContent/726792)

//!

//! A subset of TDCALL interface functions is defined in crate::tdx, and the TDG.MR.REPORT

//! leaf function and TDREPORT_STRUCT related definitions are defined in crate::tdreport

//! separately.

#![no_std]

use core::ffi::c_void;

#[cfg(feature = "use_tdx_emulation")]

pub const USE_TDX_EMULATION: bool = true;

#[cfg(not(feature = "use_tdx_emulation"))]

pub const USE_TDX_EMULATION: bool = false;

#[cfg(not(feature = "no-tdaccept"))]

pub const TDACCEPT_SUPPORT: bool = true;

#[cfg(feature = "no-tdaccept")]

pub const TDACCEPT_SUPPORT: bool = false;

pub mod asm;

pub mod tdreport;

pub mod tdx;

// Guest-Side (TDCALL) interface functions leaf numbers

const TDCALL_TDINFO: u64 = 1;

const TDCALL_TDEXTENDRTMR: u64 = 2;

const TDCALL_TDGETVEINFO: u64 = 3;

const TDCALL_TDREPORT: u64 = 4;

#[cfg(not(feature = "no-tdaccept"))]

const TDCALL_TDACCEPTPAGE: u64 = 6;

const TDCALL_VM_RD: u64 = 7;

const TDCALL_VM_WR: u64 = 8;

const TDCALL_VP_RD: u64 = 9;

const TDCALL_VP_WR: u64 = 10;

const TDCALL_SYS_RD: u64 = 11;

const TDCALL_SERVTD_RD: u64 = 18;

const TDCALL_SERVTD_WR: u64 = 20;

const TDCALL_VERIFYREPORT: u64 = 22;

const TDCALL_MEM_PAGE_ATTR_WR: u64 = 24;

const TDCALL_VP_ENTER: u64 = 25;

const TDCALL_VP_INVEPT: u64 = 26;

const TDCALL_VP_INVVPID: u64 = 27;

#[cfg(feature = "tdg_dbg")]

const TDCALL_TDG_DEBUG: u64 = 254;

// TDCALL completion status code

const TDCALL_STATUS_SUCCESS: u64 = 0;

// leaf-specific completion status code

pub const TDCALL_STATUS_PAGE_ALREADY_ACCEPTED: u64 = 0x00000B0A00000000;

pub const TDCALL_STATUS_PAGE_SIZE_MISMATCH: u64 = 0xC0000B0B00000001;

cfg_if::cfg_if! {

    if #[cfg(not(feature = "no-tdvmcall"))] {

        // GTDG.VP.VMCALL leaf sub-function numbers

        const TDVMCALL_CPUID: u64 = 0x0000a;

        const TDVMCALL_HALT: u64 = 0x0000c;

        const TDVMCALL_IO: u64 = 0x0001e;

        const TDVMCALL_RDMSR: u64 = 0x0001f;

        const TDVMCALL_WRMSR: u64 = 0x00020;

        const TDVMCALL_MMIO: u64 = 0x00030;

        const TDVMCALL_MAPGPA: u64 = 0x10001;

        const TDVMCALL_GETQUOTE: u64 = 0x10002;

        const TDVMCALL_SETUPEVENTNOTIFY: u64 = 0x10004;

        const TDVMCALL_SERVICE: u64 = 0x10005;

        const TDVMCALL_MIGTD: u64 = 0x10006;

        // TDVMCALL completion status code

        const TDVMCALL_STATUS_SUCCESS: u64 = 0;

        const TDVMCALL_STATUS_RETRY: u64 = 1;

        // TDVMCALL<MigTD> leaf function numbers

        const TDVMCALL_MIGTD_WAITFORREQUEST: u16 = 1;

        const TDVMCALL_MIGTD_REPORTSTATUS: u16 = 2;

        const TDVMCALL_MIGTD_SEND: u16= 3;

        const TDVMCALL_MIGTD_RECEIVE: u16 = 4;

    }

}

// A public wrapper for use of asm_td_vmcall, this function takes a mutable reference of a

// TdcallArgs structure to ensure the input is valid

//

// ## TDVMCALL ABI

// Defined in GHCI Spec section 'TDCALL [TDG.VP.VMCALL] leaf'

//

// ### Input Operands:

// * RAX - TDCALL instruction leaf number (0 - TDG.VP.VMCALL)

// * RCX - A bitmap that controls which part of guest TD GPR is exposed to VMM.

// * R10 - Set to 0 indicates leaf-function used in R11 is defined in standard GHCI Spec.

// * R11 - TDG.VP.VMCALL sub-function is R10 is zero

// * RBX, RBP, RDI, RSI, R8-R10, R12-R15 - Used to pass values to VMM in sub-functions.

//

// ### Output Operands:

// * RAX - TDCALL instruction return code, always return Success(0).

// * R10 - TDG.VP.VMCALL sub-function return value

// * R11 - Correspond to each TDG.VP.VMCALL.

// * R8-R9, R12-R15, RBX, RBP, RDI, RSI - Correspond to each TDG.VP.VMCALL sub-function.

//

#[cfg(not(feature = "no-tdvmcall"))]

pub fn td_vmcall(args: &mut TdVmcallArgs) -> u64 {

    unsafe { asm::asm_td_vmcall(args as *mut TdVmcallArgs as *mut c_void, 0) }

}

// An extended public wrapper for use of asm_td_vmcall.

//

// `do_sti` is a flag used to determine whether to execute `sti` instruction before `tdcall`

#[cfg(not(feature = "no-tdvmcall"))]

pub fn td_vmcall_ex(args: &mut TdVmcallArgs, do_sti: bool) -> u64 {

    unsafe { asm::asm_td_vmcall(args as *mut TdVmcallArgs as *mut c_void, do_sti as u64) }

}

// An extended public wrapper for use of asm_td_vmcall_ex.

//

// `do_sti` is a flag used to determine whether to execute `sti` instruction before `tdcall`

#[cfg(not(feature = "no-tdvmcall"))]

pub fn td_vmcall_ex2(args: &mut TdVmcallArgsEx, do_sti: bool) -> u64 {

    unsafe { asm::asm_td_vmcall_ex(args as *mut TdVmcallArgsEx as *mut c_void, do_sti as u64) }

}

// Wrapper for use of asm_td_call, this function takes a mutable reference of a

// TdVmcallArgs structure to ensure the input is valid

//

// ## TDCALL ABI

// Defined in TDX Module 1.0 Spec section 'TDCALL Instruction (Common)'

//

// ### Input Operands:

//  * RAX - Leaf and version numbers.

//  * Other - Used by leaf functions as input values.

//

// ### Output Operands:

//  * RAX - Instruction return code.

//  * Other - Used by leaf functions as output values.

//

pub fn td_call(args: &mut TdcallArgs) -> u64 {

    unsafe { asm::asm_td_call(args as *mut TdcallArgs as *mut c_void) }

}

// Used to pass the values of input/output register when performing TDVMCALL

// instruction

#[repr(C)]

#[derive(Default)]

pub struct TdcallArgs {

    pub rax: u64,

    pub rcx: u64,

    pub rdx: u64,

    pub r8: u64,

    pub r9: u64,

    pub r10: u64,

    pub r11: u64,

    pub r12: u64,

    pub r13: u64,

    pub r14: u64,

}

// Used to pass the values of input/output register when performing TDVMCALL

// instruction

#[cfg(not(feature = "no-tdvmcall"))]

#[repr(C)]

#[derive(Default)]

pub struct TdVmcallArgs {

    // Input: Always 0 for  (standard VMCALL)

    // Output: Sub-function

    pub r10: u64,

    pub r11: u64,

    pub r12: u64,

    pub r13: u64,

    pub r14: u64,

    pub r15: u64,

}

// Used to pass the values of input/output register when performing TDVMCALL

// instruction

#[cfg(not(feature = "no-tdvmcall"))]

#[repr(C)]

#[derive(Default)]

pub struct TdVmcallArgsEx {

    // Input: Always 0 for  (standard VMCALL)

    // Output: Sub-function

    pub rdx: u64,

    pub rbx: u64,

    pub rsi: u64,

    pub rdi: u64,

    pub r8: u64,

    pub r9: u64,

    pub r10: u64,

    pub r11: u64,

    pub r12: u64,

    pub r13: u64,

    pub r14: u64,

    pub r15: u64,

}

/// TDCALL instruction return error code

///

/// Refer to Intel TDX Module 1.0 Specifiction section 'TDCALL Instruction (Common)'

#[derive(Debug, PartialEq)]

pub enum TdCallError {

    // Invalid parameters

    TdxExitInvalidParameters,

    // The operand is busy (e.g., it is locked in Exclusive mode)

    TdxExitReasonOperandBusy(u32),

    // Operand is invalid (e.g., illegal leaf number)

    TdxExitReasonOperandInvalid(u32),

    // Error code defined by individual leaf function

    LeafSpecific(u64),

}

// TDCALL Completion Status Codes (Returned in RAX) Definition

impl From<u64> for TdCallError {

    fn from(val: u64) -> Self {

        match val >> 32 {

            0x8000_0200 => Self::TdxExitReasonOperandBusy(val as u32),

            0xC000_0100 => Self::TdxExitReasonOperandInvalid(val as u32),

            _ => Self::LeafSpecific(val),

        }

    }

}

/// TDVMCALL sub-function return error code

///

/// Refer to Guest-Host-Communication-Interface(GHCI) for Intel TDX

/// table 'TDCALL[TDG.VP.VMCALL]- Sub-function Completion-Status Codes'

#[cfg(not(feature = "no-tdvmcall"))]

#[derive(Debug, PartialEq)]

pub enum TdVmcallError {

    // TDCALL[TDG.VP.VMCALL] sub-function invocation must be retried

    VmcallRetry,

    // Invalid operand to TDG.VP.VMCALL sub-function

    VmcallOperandInvalid,

    // GPA already mapped

    VmcallGpaInuse,

    // Operand (address) alignment error

    VmcallAlignError,

    Other,

}

#[cfg(not(feature = "no-tdvmcall"))]

impl From<u64> for TdVmcallError {

    fn from(val: u64) -> Self {

        match val {

            0x1 => TdVmcallError::VmcallRetry,

            0x8000_0000_0000_0000 => TdVmcallError::VmcallOperandInvalid,

            0x8000_0000_0000_0001 => TdVmcallError::VmcallGpaInuse,

            0x8000_0000_0000_0002 => TdVmcallError::VmcallAlignError,

            _ => TdVmcallError::Other,

        }

    }

}