2023-09-28 03:47:55 +08:00

303 lines
7.6 KiB
Rust

//! The TDVMCALL helps invoke services from the host VMM. From the perspective of the host VMM, the TDVMCALL is a trap-like, VM exit into
//! the host VMM, reported via the SEAMRET instruction flow.
//! By design, after the SEAMRET, the host VMM services the request specified in the parameters
//! passed by the TD during the TDG.VP.VMCALL (that are passed via SEAMRET to the VMM), then
//! resumes the TD via a SEAMCALL [TDH.VP.ENTER] invocation.
extern crate alloc;
use crate::asm::asm_td_vmcall;
use alloc::fmt;
use bitflags::bitflags;
use core::fmt::Write;
use x86_64::{
registers::rflags::{self, RFlags},
structures::port::PortRead,
};
/// TDVMCALL Instruction Leaf Numbers Definition.
#[repr(u64)]
pub enum TdVmcallNum {
Cpuid = 0x0000a,
Hlt = 0x0000c,
Io = 0x0001e,
Rdmsr = 0x0001f,
Wrmsr = 0x00020,
RequestMmio = 0x00030,
Wbinvd = 0x00036,
Pconfig = 0x00041,
Mapgpa = 0x10001,
}
const SERIAL_IO_PORT: u16 = 0x3F8;
const SERIAL_LINE_STS: u16 = 0x3FD;
const IO_READ: u64 = 0;
const IO_WRITE: u64 = 1;
#[derive(Debug, PartialEq)]
pub enum TdVmcallError {
/// TDCALL[TDG.VP.VMCALL] sub-function invocation must be retried.
TdxRetry,
/// Invalid operand to TDG.VP.VMCALL sub-function.
TdxInvalidOperand,
/// GPA already mapped.
TdxGpaInuse,
/// Operand (address) aligned error.
TdxAlignError,
Other,
}
impl From<u64> for TdVmcallError {
fn from(val: u64) -> Self {
match val {
0x1 => Self::TdxRetry,
0x8000_0000_0000_0000 => Self::TdxInvalidOperand,
0x8000_0000_0000_0001 => Self::TdxGpaInuse,
0x8000_0000_0000_0002 => Self::TdxAlignError,
_ => Self::Other,
}
}
}
#[repr(C)]
#[derive(Default)]
pub(crate) struct TdVmcallArgs {
r10: u64,
r11: u64,
r12: u64,
r13: u64,
r14: u64,
r15: u64,
}
#[repr(C)]
#[derive(Debug, Default)]
pub struct CpuIdInfo {
pub eax: usize,
pub ebx: usize,
pub ecx: usize,
pub edx: usize,
}
pub enum Direction {
In,
Out,
}
pub enum Operand {
Dx,
Immediate,
}
pub enum IoSize {
Size1 = 1,
Size2 = 2,
Size4 = 4,
Size8 = 8,
}
pub fn cpuid(eax: u32, ecx: u32) -> Result<CpuIdInfo, TdVmcallError> {
let mut args = TdVmcallArgs {
r11: TdVmcallNum::Cpuid as u64,
r12: eax as u64,
r13: ecx as u64,
..Default::default()
};
td_vmcall(&mut args)?;
Ok(CpuIdInfo {
eax: args.r12 as usize,
ebx: args.r13 as usize,
ecx: args.r14 as usize,
edx: args.r15 as usize,
})
}
pub fn hlt() {
let interrupt_blocked = !rflags::read().contains(RFlags::INTERRUPT_FLAG);
let mut args = TdVmcallArgs {
r11: TdVmcallNum::Hlt as u64,
r12: interrupt_blocked as u64,
..Default::default()
};
let _ = td_vmcall(&mut args);
}
/// # Safety
/// Make sure the index is valid.
pub unsafe fn rdmsr(index: u32) -> Result<u64, TdVmcallError> {
let mut args = TdVmcallArgs {
r11: TdVmcallNum::Rdmsr as u64,
r12: index as u64,
..Default::default()
};
td_vmcall(&mut args)?;
Ok(args.r11)
}
/// # Safety
/// Make sure the index and the corresponding value are valid.
pub unsafe fn wrmsr(index: u32, value: u64) -> Result<(), TdVmcallError> {
let mut args = TdVmcallArgs {
r11: TdVmcallNum::Wrmsr as u64,
r12: index as u64,
r13: value,
..Default::default()
};
td_vmcall(&mut args)
}
/// Used to help perform WBINVD or WBNOINVD operation.
/// - cache_operation: 0: WBINVD, 1: WBNOINVD
pub fn perform_cache_operation(cache_operation: u64) -> Result<(), TdVmcallError> {
let mut args = TdVmcallArgs {
r11: TdVmcallNum::Wbinvd as u64,
r12: cache_operation,
..Default::default()
};
td_vmcall(&mut args)
}
/// # Safety
/// Make sure the mmio address is valid.
pub unsafe fn read_mmio(size: IoSize, mmio_gpa: &[u8]) -> Result<u64, TdVmcallError> {
let mut args = TdVmcallArgs {
r11: TdVmcallNum::RequestMmio as u64,
r12: size as u64,
r13: 0,
r14: mmio_gpa.as_ptr() as u64,
..Default::default()
};
td_vmcall(&mut args)?;
Ok(args.r11)
}
/// # Safety
/// Make sure the mmio address is valid.
pub unsafe fn write_mmio(size: IoSize, mmio_gpa: &[u8], data: u64) -> Result<(), TdVmcallError> {
let mut args = TdVmcallArgs {
r11: TdVmcallNum::RequestMmio as u64,
r12: size as u64,
r13: 1,
r14: mmio_gpa.as_ptr() as u64,
r15: data,
..Default::default()
};
td_vmcall(&mut args)
}
macro_rules! io_read {
($port:expr, $ty:ty) => {{
let mut args = TdVmcallArgs {
r11: TdVmcallNum::Io as u64,
r12: core::mem::size_of::<$ty>() as u64,
r13: IO_READ,
r14: $port as u64,
..Default::default()
};
td_vmcall(&mut args)?;
Ok(args.r11 as u32)
}};
}
pub fn io_read(size: IoSize, port: u16) -> Result<u32, TdVmcallError> {
match size {
IoSize::Size1 => io_read!(port, u8),
IoSize::Size2 => io_read!(port, u16),
IoSize::Size4 => io_read!(port, u32),
_ => unreachable!(),
}
}
macro_rules! io_write {
($port:expr, $byte:expr, $size:expr) => {{
let mut args = TdVmcallArgs {
r11: TdVmcallNum::Io as u64,
r12: core::mem::size_of_val(&$byte) as u64,
r13: IO_WRITE,
r14: $port as u64,
r15: $byte as u64,
..Default::default()
};
td_vmcall(&mut args)
}};
}
pub fn io_write(size: IoSize, port: u16, byte: u32) -> Result<(), TdVmcallError> {
match size {
IoSize::Size1 => io_write!(port, byte, u8),
IoSize::Size2 => io_write!(port, byte, u16),
IoSize::Size4 => io_write!(port, byte, u32),
_ => unreachable!(),
}
}
fn td_vmcall(args: &mut TdVmcallArgs) -> Result<(), TdVmcallError> {
let result = unsafe { asm_td_vmcall(args) };
match result {
0 => Ok(()),
_ => Err(result.into()),
}
}
bitflags! {
/// LineSts: Line Status
struct LineSts: u8 {
const INPUT_FULL = 1;
const OUTPUT_EMPTY = 1 << 5;
}
}
fn read_line_sts() -> LineSts {
LineSts::from_bits_truncate(unsafe { PortRead::read_from_port(SERIAL_LINE_STS) })
}
struct Serial;
impl Serial {
fn serial_write_byte(byte: u8) {
match byte {
// Backspace/Delete
8 | 0x7F => {
while !read_line_sts().contains(LineSts::OUTPUT_EMPTY) {}
io_write!(SERIAL_IO_PORT, 8, u8).unwrap();
while !read_line_sts().contains(LineSts::OUTPUT_EMPTY) {}
io_write!(SERIAL_IO_PORT, b' ', u8).unwrap();
while !read_line_sts().contains(LineSts::OUTPUT_EMPTY) {}
io_write!(SERIAL_IO_PORT, 8, u8).unwrap();
}
_ => {
while !read_line_sts().contains(LineSts::OUTPUT_EMPTY) {}
io_write!(SERIAL_IO_PORT, byte, u8).unwrap();
}
}
}
}
impl Write for Serial {
fn write_str(&mut self, s: &str) -> fmt::Result {
for &c in s.as_bytes() {
Serial::serial_write_byte(c);
}
Ok(())
}
}
pub fn print(args: fmt::Arguments) {
Serial
.write_fmt(args)
.expect("Failed to write to serial port");
}
#[macro_export]
macro_rules! serial_print {
($fmt: literal $(, $($arg: tt)+)?) => {
$crate::tdvmcall::print(format_args!($fmt $(, $($arg)+)?));
}
}
#[macro_export]
macro_rules! serial_println {
($fmt: literal $(, $($arg: tt)+)?) => {
$crate::tdvmcall::print(format_args!(concat!($fmt, "\n") $(, $($arg)+)?))
}
}