cloud-hypervisor/devices/src/tpm.rs
Praveen K Paladugu d0b253d15f devices: Add tpm device
This device emulates a tpm device in cloud-hypervisor. Read and write support
to miminal set of control registers is supported.

Non-control commands will be processed as reads and write to
CRB_DATA_BUFFER. Reads and Writes to this data buffer are forwarded to
swtpm via the configured data_fd.

Signed-off-by: Praveen K Paladugu <prapal@linux.microsoft.com>
Co-authored-by: Sean Yoo <t-seanyoo@microsoft.com>
2022-11-15 16:42:21 +00:00

471 lines
16 KiB
Rust

// Copyright © 2022, Microsoft Corporation
//
// SPDX-License-Identifier: Apache-2.0
//
use anyhow::anyhow;
#[cfg(target_arch = "aarch64")]
use arch::aarch64::layout::{TPM_SIZE, TPM_START};
#[cfg(target_arch = "x86_64")]
use arch::x86_64::layout::{TPM_SIZE, TPM_START};
use phf::phf_map;
use std::cmp;
use std::sync::{Arc, Barrier};
use thiserror::Error;
use tpm::emulator::{BackendCmd, Emulator};
use tpm::TPM_CRB_BUFFER_MAX;
use tpm::TPM_SUCCESS;
use vm_device::BusDevice;
#[derive(Error, Debug)]
pub enum Error {
#[error("Emulator doesn't implement min required capabilities: {0}")]
CheckCaps(#[source] anyhow::Error),
#[error("Failed to initialize tpm: {0}")]
Init(#[source] anyhow::Error),
#[error("Failed to deliver tpm Command: {0}")]
DeliverRequest(#[source] anyhow::Error),
}
type Result<T> = anyhow::Result<T, Error>;
/* crb 32-bit registers */
const CRB_LOC_STATE: u32 = 0x0;
//Register Fields
// Field => (start, length)
// start: lowest bit in the bit field numbered from 0
// length: length of the bit field
const CRB_LOC_STATE_FIELDS: phf::Map<&str, [u32; 2]> = phf_map! {
"tpmEstablished" => [0, 1],
"locAssigned" => [1,1],
"activeLocality"=> [2, 3],
"reserved" => [5, 2],
"tpmRegValidSts" => [7, 1]
};
const CRB_LOC_CTRL: u32 = 0x08;
const CRB_LOC_CTRL_REQUEST_ACCESS: u32 = 1 << 0;
const CRB_LOC_CTRL_RELINQUISH: u32 = 1 << 1;
const CRB_LOC_CTRL_RESET_ESTABLISHMENT_BIT: u32 = 1 << 3;
const CRB_LOC_STS: u32 = 0x0C;
const CRB_LOC_STS_FIELDS: phf::Map<&str, [u32; 2]> = phf_map! {
"Granted" => [0, 1],
"beenSeized" => [1,1]
};
const CRB_INTF_ID: u32 = 0x30;
const CRB_INTF_ID_FIELDS: phf::Map<&str, [u32; 2]> = phf_map! {
"InterfaceType" => [0, 4],
"InterfaceVersion" => [4, 4],
"CapLocality" => [8, 1],
"CapCRBIdleBypass" => [9, 1],
"Reserved1" => [10, 1],
"CapDataXferSizeSupport" => [11, 2],
"CapFIFO" => [13, 1],
"CapCRB" => [14, 1],
"CapIFRes" => [15, 2],
"InterfaceSelector" => [17, 2],
"IntfSelLock" => [19, 1],
"Reserved2" => [20, 4],
"RID" => [24, 8]
};
const CRB_INTF_ID2: u32 = 0x34;
const CRB_INTF_ID2_FIELDS: phf::Map<&str, [u32; 2]> = phf_map! {
"VID" => [0, 16],
"DID" => [16, 16]
};
const CRB_CTRL_REQ: u32 = 0x40;
const CRB_CTRL_REQ_CMD_READY: u32 = 1 << 0;
const CRB_CTRL_REQ_GO_IDLE: u32 = 1 << 1;
const CRB_CTRL_STS: u32 = 0x44;
const CRB_CTRL_STS_FIELDS: phf::Map<&str, [u32; 2]> = phf_map! {
"tpmSts" => [0, 1],
"tpmIdle" => [1, 1]
};
const CRB_CTRL_CANCEL: u32 = 0x48;
const CRB_CANCEL_INVOKE: u32 = 1 << 0;
const CRB_CTRL_START: u32 = 0x4C;
const CRB_START_INVOKE: u32 = 1 << 0;
const CRB_CTRL_CMD_LADDR: u32 = 0x5C;
const CRB_CTRL_CMD_HADDR: u32 = 0x60;
const CRB_CTRL_RSP_SIZE: u32 = 0x64;
const CRB_CTRL_RSP_ADDR: u32 = 0x68;
const CRB_DATA_BUFFER: u32 = 0x80;
const TPM_CRB_NO_LOCALITY: u32 = 0xff;
const TPM_CRB_ADDR_BASE: u32 = TPM_START.0 as u32;
const TPM_CRB_ADDR_SIZE: usize = TPM_SIZE as usize;
const TPM_CRB_R_MAX: u32 = CRB_DATA_BUFFER;
// CRB Protocol details
const CRB_INTF_TYPE_CRB_ACTIVE: u32 = 0b1;
const CRB_INTF_VERSION_CRB: u32 = 0b1;
const CRB_INTF_CAP_LOCALITY_0_ONLY: u32 = 0b0;
const CRB_INTF_CAP_IDLE_FAST: u32 = 0b0;
const CRB_INTF_CAP_XFER_SIZE_64: u32 = 0b11;
const CRB_INTF_CAP_FIFO_NOT_SUPPORTED: u32 = 0b0;
const CRB_INTF_CAP_CRB_SUPPORTED: u32 = 0b1;
const CRB_INTF_IF_SELECTOR_CRB: u32 = 0b1;
const PCI_VENDOR_ID_IBM: u32 = 0x1014;
const CRB_CTRL_CMD_SIZE_REG: u32 = 0x58;
const CRB_CTRL_CMD_SIZE: usize = TPM_CRB_ADDR_SIZE - CRB_DATA_BUFFER as usize;
fn get_fields_map(reg: u32) -> phf::Map<&'static str, [u32; 2]> {
match reg {
CRB_LOC_STATE => CRB_LOC_STATE_FIELDS,
CRB_LOC_STS => CRB_LOC_STS_FIELDS,
CRB_INTF_ID => CRB_INTF_ID_FIELDS,
CRB_INTF_ID2 => CRB_INTF_ID2_FIELDS,
CRB_CTRL_STS => CRB_CTRL_STS_FIELDS,
_ => {
panic!(
"Fields in '{:?}' register were accessed which are Invalid",
reg
);
}
}
}
/// Set a particular field in a Register
fn set_reg_field(regs: &mut [u32; TPM_CRB_R_MAX as usize], reg: u32, field: &str, value: u32) {
let reg_fields = get_fields_map(reg);
if reg_fields.contains_key(field) {
let start = reg_fields.get(field).unwrap()[0];
let len = reg_fields.get(field).unwrap()[1];
let mask = (!(0_u32) >> (32 - len)) << start;
regs[reg as usize] = (regs[reg as usize] & !mask) | ((value << start) & mask);
} else {
error!(
"Failed to tpm Register. {:?} is not a valid field in Reg {:#X}",
field, reg
)
}
}
/// Get the value of a particular field in a Register
fn get_reg_field(regs: &[u32; TPM_CRB_R_MAX as usize], reg: u32, field: &str) -> u32 {
let reg_fields = get_fields_map(reg);
if reg_fields.contains_key(field) {
let start = reg_fields.get(field).unwrap()[0];
let len = reg_fields.get(field).unwrap()[1];
let mask = (!(0_u32) >> (32 - len)) << start;
(regs[reg as usize] & mask) >> start
} else {
// TODO: Sensible return value if fields do not exist
0x0
}
}
fn locality_from_addr(addr: u32) -> u8 {
(addr >> 12) as u8
}
pub struct Tpm {
emulator: Emulator,
cmd: Option<BackendCmd>,
regs: [u32; TPM_CRB_R_MAX as usize],
backend_buff_size: usize,
data_buff: [u8; TPM_CRB_BUFFER_MAX],
data_buff_len: usize,
}
impl Tpm {
pub fn new(path: String) -> Result<Self> {
let emulator = Emulator::new(path)
.map_err(|e| Error::Init(anyhow!("Failed while initializing tpm Emulator: {:?}", e)))?;
let mut tpm = Tpm {
emulator,
cmd: None,
regs: [0; TPM_CRB_R_MAX as usize],
backend_buff_size: TPM_CRB_BUFFER_MAX,
data_buff: [0; TPM_CRB_BUFFER_MAX],
data_buff_len: 0,
};
tpm.reset()?;
Ok(tpm)
}
fn get_active_locality(&mut self) -> u32 {
if get_reg_field(&self.regs, CRB_LOC_STATE, "locAssigned") == 0 {
return TPM_CRB_NO_LOCALITY;
}
get_reg_field(&self.regs, CRB_LOC_STATE, "activeLocality")
}
fn request_completed(&mut self, result: isize) {
self.regs[CRB_CTRL_START as usize] = !CRB_START_INVOKE;
if result != 0 {
set_reg_field(&mut self.regs, CRB_CTRL_STS, "tpmSts", 1);
}
}
fn reset(&mut self) -> Result<()> {
let cur_buff_size = self.emulator.get_buffer_size().unwrap();
self.regs = [0; TPM_CRB_R_MAX as usize];
set_reg_field(&mut self.regs, CRB_LOC_STATE, "tpmRegValidSts", 1);
set_reg_field(&mut self.regs, CRB_CTRL_STS, "tpmIdle", 1);
set_reg_field(
&mut self.regs,
CRB_INTF_ID,
"InterfaceType",
CRB_INTF_TYPE_CRB_ACTIVE,
);
set_reg_field(
&mut self.regs,
CRB_INTF_ID,
"InterfaceVersion",
CRB_INTF_VERSION_CRB,
);
set_reg_field(
&mut self.regs,
CRB_INTF_ID,
"CapLocality",
CRB_INTF_CAP_LOCALITY_0_ONLY,
);
set_reg_field(
&mut self.regs,
CRB_INTF_ID,
"CapCRBIdleBypass",
CRB_INTF_CAP_IDLE_FAST,
);
set_reg_field(
&mut self.regs,
CRB_INTF_ID,
"CapDataXferSizeSupport",
CRB_INTF_CAP_XFER_SIZE_64,
);
set_reg_field(
&mut self.regs,
CRB_INTF_ID,
"CapFIFO",
CRB_INTF_CAP_FIFO_NOT_SUPPORTED,
);
set_reg_field(
&mut self.regs,
CRB_INTF_ID,
"CapCRB",
CRB_INTF_CAP_CRB_SUPPORTED,
);
set_reg_field(
&mut self.regs,
CRB_INTF_ID,
"InterfaceSelector",
CRB_INTF_IF_SELECTOR_CRB,
);
set_reg_field(&mut self.regs, CRB_INTF_ID, "RID", 0b0000);
set_reg_field(&mut self.regs, CRB_INTF_ID2, "VID", PCI_VENDOR_ID_IBM);
self.regs[CRB_CTRL_CMD_SIZE_REG as usize] = CRB_CTRL_CMD_SIZE as u32;
self.regs[CRB_CTRL_CMD_LADDR as usize] = TPM_CRB_ADDR_BASE + CRB_DATA_BUFFER;
self.regs[CRB_CTRL_RSP_SIZE as usize] = CRB_CTRL_CMD_SIZE as u32;
self.regs[CRB_CTRL_RSP_ADDR as usize] = TPM_CRB_ADDR_BASE + CRB_DATA_BUFFER;
self.backend_buff_size = cmp::min(cur_buff_size, TPM_CRB_BUFFER_MAX);
if let Err(e) = self.emulator.startup_tpm(self.backend_buff_size) {
return Err(Error::Init(anyhow!(
"Failed while running Startup TPM. Error: {:?}",
e
)));
}
Ok(())
}
}
//impl BusDevice for TPM
impl BusDevice for Tpm {
fn read(&mut self, _base: u64, offset: u64, data: &mut [u8]) {
let mut offset: u32 = offset as u32;
let read_len: usize = data.len();
if offset >= CRB_DATA_BUFFER
&& (offset + read_len as u32) < (CRB_DATA_BUFFER + self.data_buff.len() as u32)
{
// Read from Data Buffer
let start: usize = (offset as usize) - (CRB_DATA_BUFFER as usize);
let end: usize = start + read_len;
data[..].clone_from_slice(&self.data_buff[start..end]);
} else {
offset &= 0xff;
let mut val = self.regs[offset as usize];
if offset == CRB_LOC_STATE && !self.emulator.get_established_flag() {
val |= 0x1;
}
if data.len() <= 4 {
data.clone_from_slice(val.to_ne_bytes()[0..read_len].as_ref());
} else {
error!(
"Invalid tpm read: offset {:#X}, data length {:?}",
offset,
data.len()
);
}
}
debug!(
"MMIO Read: offset {:#X} len {:?} val = {:02X?} ",
offset,
data.len(),
data
);
}
fn write(&mut self, _base: u64, offset: u64, data: &[u8]) -> Option<Arc<Barrier>> {
debug!(
"MMIO Write: offset {:#X} len {:?} input data {:02X?}",
offset,
data.len(),
data
);
let mut offset: u32 = offset as u32;
if offset < CRB_DATA_BUFFER {
offset &= 0xff;
}
let locality = locality_from_addr(offset) as u32;
let write_len = data.len();
if offset >= CRB_DATA_BUFFER
&& (offset + write_len as u32) < (CRB_DATA_BUFFER + self.data_buff.len() as u32)
{
let start: usize = (offset as usize) - (CRB_DATA_BUFFER as usize);
if start == 0 {
// If filling data_buff at index 0, reset length to 0
self.data_buff_len = 0;
self.data_buff.fill(0);
}
let end: usize = start + data.len();
self.data_buff[start..end].clone_from_slice(data);
self.data_buff_len += data.len();
} else {
// Ctrl Commands that take more than 4 bytes as input are not yet supported
// CTRL_RSP_ADDR usually gets 8 byte write request. Last 4 bytes are zeros.
if write_len > 4 && offset != CRB_CTRL_RSP_ADDR {
error!(
"Invalid tpm write: offset {:#X}, data length {}",
offset,
data.len()
);
return None;
}
let mut input: [u8; 4] = [0; 4];
input.copy_from_slice(&data[0..4]);
let v = u32::from_le_bytes(input);
match offset {
CRB_CTRL_CMD_SIZE_REG => {
self.regs[CRB_CTRL_CMD_SIZE_REG as usize] = v;
}
CRB_CTRL_CMD_LADDR => {
self.regs[CRB_CTRL_CMD_LADDR as usize] = v;
}
CRB_CTRL_CMD_HADDR => {
self.regs[CRB_CTRL_CMD_HADDR as usize] = v;
}
CRB_CTRL_RSP_SIZE => {
self.regs[CRB_CTRL_RSP_SIZE as usize] = v;
}
CRB_CTRL_RSP_ADDR => {
self.regs[CRB_CTRL_RSP_ADDR as usize] = v;
}
CRB_CTRL_REQ => match v {
CRB_CTRL_REQ_CMD_READY => {
set_reg_field(&mut self.regs, CRB_CTRL_STS, "tpmIdle", 0);
}
CRB_CTRL_REQ_GO_IDLE => {
set_reg_field(&mut self.regs, CRB_CTRL_STS, "tpmIdle", 1);
}
_ => {
error!("Invalid value passed to CRTL_REQ register");
return None;
}
},
CRB_CTRL_CANCEL => {
if v == CRB_CANCEL_INVOKE
&& (self.regs[CRB_CTRL_START as usize] & CRB_START_INVOKE != 0)
{
if let Err(e) = self.emulator.cancel_cmd() {
error!("Failed to run cancel command. Error: {:?}", e);
}
}
}
CRB_CTRL_START => {
if v == CRB_START_INVOKE
&& ((self.regs[CRB_CTRL_START as usize] & CRB_START_INVOKE) == 0)
&& self.get_active_locality() == locality
{
self.regs[CRB_CTRL_START as usize] |= CRB_START_INVOKE;
self.cmd = Some(BackendCmd {
locality: locality as u8,
input: self.data_buff[0..self.data_buff_len].to_vec(),
input_len: cmp::min(self.data_buff_len, TPM_CRB_BUFFER_MAX),
output: self.data_buff.to_vec(),
output_len: TPM_CRB_BUFFER_MAX,
selftest_done: false,
});
let mut cmd = self.cmd.as_ref().unwrap().clone();
let output = self.emulator.deliver_request(&mut cmd).map_err(|e| {
Error::DeliverRequest(anyhow!(
"Failed to deliver tpm request. Error :{:?}",
e
))
});
//TODO: drop the copy here
self.data_buff.fill(0);
self.data_buff.clone_from_slice(output.unwrap().as_slice());
self.request_completed(TPM_SUCCESS as isize);
}
}
CRB_LOC_CTRL => {
warn!(
"CRB_LOC_CTRL locality to write = {:?} val = {:?}",
locality, v
);
match v {
CRB_LOC_CTRL_RESET_ESTABLISHMENT_BIT => {}
CRB_LOC_CTRL_RELINQUISH => {
set_reg_field(&mut self.regs, CRB_LOC_STATE, "locAssigned", 0);
set_reg_field(&mut self.regs, CRB_LOC_STS, "Granted", 0);
}
CRB_LOC_CTRL_REQUEST_ACCESS => {
set_reg_field(&mut self.regs, CRB_LOC_STS, "Granted", 1);
set_reg_field(&mut self.regs, CRB_LOC_STS, "beenSeized", 0);
set_reg_field(&mut self.regs, CRB_LOC_STATE, "locAssigned", 1);
}
_ => {
error!("Invalid value to write in CRB_LOC_CTRL {:#X} ", v);
}
}
}
_ => {
error!(
"Invalid tpm write: offset {:#X}, data length {:?}",
offset,
data.len()
);
}
}
}
None
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_set_get_reg_field() {
let mut regs: [u32; TPM_CRB_R_MAX as usize] = [0; TPM_CRB_R_MAX as usize];
set_reg_field(&mut regs, CRB_INTF_ID, "RID", 0xAC);
assert_eq!(
get_reg_field(&regs, CRB_INTF_ID, "RID"),
0xAC,
concat!("Test: ", stringify!(set_get_reg_field))
);
}
}