cloud-hypervisor/virtio-devices/src/console.rs

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// Copyright 2019 Intel Corporation. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
use super::Error as DeviceError;
use super::{
ActivateError, ActivateResult, EpollHelper, EpollHelperError, EpollHelperHandler, Queue,
VirtioCommon, VirtioDevice, VirtioDeviceType, VirtioInterruptType, EPOLL_HELPER_EVENT_LAST,
VIRTIO_F_IOMMU_PLATFORM, VIRTIO_F_VERSION_1,
};
use crate::seccomp_filters::{get_seccomp_filter, Thread};
use crate::VirtioInterrupt;
use anyhow::anyhow;
use libc::EFD_NONBLOCK;
use seccomp::{SeccompAction, SeccompFilter};
use serde::ser::{Serialize, SerializeStruct, Serializer};
use std::cmp;
use std::collections::VecDeque;
use std::io;
use std::io::Write;
use std::ops::DerefMut;
use std::os::unix::io::AsRawFd;
use std::result;
use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
use std::sync::{Arc, Barrier, Mutex};
use std::thread;
use vm_memory::{ByteValued, Bytes, GuestAddressSpace, GuestMemoryAtomic, GuestMemoryMmap};
use vm_migration::{
Migratable, MigratableError, Pausable, Snapshot, SnapshotDataSection, Snapshottable,
Transportable,
};
use vmm_sys_util::eventfd::EventFd;
const QUEUE_SIZE: u16 = 256;
const NUM_QUEUES: usize = 2;
const QUEUE_SIZES: &[u16] = &[QUEUE_SIZE; NUM_QUEUES];
// New descriptors are pending on the virtio queue.
const INPUT_QUEUE_EVENT: u16 = EPOLL_HELPER_EVENT_LAST + 1;
const OUTPUT_QUEUE_EVENT: u16 = EPOLL_HELPER_EVENT_LAST + 2;
// Some input from the VMM is ready to be injected into the VM.
const INPUT_EVENT: u16 = EPOLL_HELPER_EVENT_LAST + 3;
// Console configuration change event is triggered.
const CONFIG_EVENT: u16 = EPOLL_HELPER_EVENT_LAST + 4;
//Console size feature bit
const VIRTIO_CONSOLE_F_SIZE: u64 = 0;
#[derive(Copy, Clone, Debug, Default, Deserialize)]
#[repr(C, packed)]
pub struct VirtioConsoleConfig {
cols: u16,
rows: u16,
max_nr_ports: u32,
emerg_wr: u32,
}
// We must explicitly implement Serialize since the structure is packed and
// it's unsafe to borrow from a packed structure. And by default, if we derive
// Serialize from serde, it will borrow the values from the structure.
// That's why this implementation copies each field separately before it
// serializes the entire structure field by field.
impl Serialize for VirtioConsoleConfig {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
let cols = self.cols;
let rows = self.rows;
let max_nr_ports = self.max_nr_ports;
let emerg_wr = self.emerg_wr;
let mut virtio_console_config = serializer.serialize_struct("VirtioConsoleConfig", 12)?;
virtio_console_config.serialize_field("cols", &cols)?;
virtio_console_config.serialize_field("rows", &rows)?;
virtio_console_config.serialize_field("max_nr_ports", &max_nr_ports)?;
virtio_console_config.serialize_field("emerg_wr", &emerg_wr)?;
virtio_console_config.end()
}
}
// Safe because it only has data and has no implicit padding.
unsafe impl ByteValued for VirtioConsoleConfig {}
struct ConsoleEpollHandler {
queues: Vec<Queue>,
mem: GuestMemoryAtomic<GuestMemoryMmap>,
interrupt_cb: Arc<dyn VirtioInterrupt>,
in_buffer: Arc<Mutex<VecDeque<u8>>>,
out: Arc<Mutex<Box<dyn io::Write + Send + Sync + 'static>>>,
input_queue_evt: EventFd,
output_queue_evt: EventFd,
input_evt: EventFd,
config_evt: EventFd,
kill_evt: EventFd,
pause_evt: EventFd,
}
impl ConsoleEpollHandler {
/*
* Each port of virtio console device has one receive
* queue. One or more empty buffers are placed by the
* dirver in the receive queue for incoming data. Here,
* we place the input data to these empty buffers.
*/
fn process_input_queue(&mut self) -> bool {
let mut in_buffer = self.in_buffer.lock().unwrap();
let recv_queue = &mut self.queues[0]; //receiveq
let mut used_desc_heads = [(0, 0); QUEUE_SIZE as usize];
let mut used_count = 0;
if in_buffer.is_empty() {
return false;
}
let mem = self.mem.memory();
for avail_desc in recv_queue.iter(&mem) {
let len = cmp::min(avail_desc.len as u32, in_buffer.len() as u32);
let source_slice = in_buffer.drain(..len as usize).collect::<Vec<u8>>();
if let Err(e) = mem.write_slice(&source_slice[..], avail_desc.addr) {
error!("Failed to write slice: {:?}", e);
recv_queue.go_to_previous_position();
break;
}
used_desc_heads[used_count] = (avail_desc.index, len);
used_count += 1;
if in_buffer.is_empty() {
break;
}
}
for &(desc_index, len) in &used_desc_heads[..used_count] {
recv_queue.add_used(&mem, desc_index, len);
}
used_count > 0
}
/*
* Each port of virtio console device has one transmit
* queue. For outgoing data, characters are placed in
* the transmit queue by the driver. Therefore, here
* we read data from the transmit queue and flush them
* to the referenced address.
*/
fn process_output_queue(&mut self) -> bool {
let trans_queue = &mut self.queues[1]; //transmitq
let mut used_desc_heads = [(0, 0); QUEUE_SIZE as usize];
let mut used_count = 0;
let mem = self.mem.memory();
for avail_desc in trans_queue.iter(&mem) {
let len;
let mut out = self.out.lock().unwrap();
let _ = mem.write_to(
avail_desc.addr,
&mut out.deref_mut(),
avail_desc.len as usize,
);
let _ = out.flush();
len = avail_desc.len;
used_desc_heads[used_count] = (avail_desc.index, len);
used_count += 1;
}
for &(desc_index, len) in &used_desc_heads[..used_count] {
trans_queue.add_used(&mem, desc_index, len);
}
used_count > 0
}
fn signal_used_queue(&self) -> result::Result<(), DeviceError> {
self.interrupt_cb
.trigger(&VirtioInterruptType::Queue, Some(&self.queues[0]))
.map_err(|e| {
error!("Failed to signal used queue: {:?}", e);
DeviceError::FailedSignalingUsedQueue(e)
})
}
fn run(
&mut self,
paused: Arc<AtomicBool>,
paused_sync: Arc<Barrier>,
) -> result::Result<(), EpollHelperError> {
let mut helper = EpollHelper::new(&self.kill_evt, &self.pause_evt)?;
helper.add_event(self.input_queue_evt.as_raw_fd(), INPUT_QUEUE_EVENT)?;
helper.add_event(self.output_queue_evt.as_raw_fd(), OUTPUT_QUEUE_EVENT)?;
helper.add_event(self.input_evt.as_raw_fd(), INPUT_EVENT)?;
helper.add_event(self.config_evt.as_raw_fd(), CONFIG_EVENT)?;
helper.run(paused, paused_sync, self)?;
Ok(())
}
}
impl EpollHelperHandler for ConsoleEpollHandler {
fn handle_event(&mut self, _helper: &mut EpollHelper, event: &epoll::Event) -> bool {
let ev_type = event.data as u16;
match ev_type {
INPUT_QUEUE_EVENT => {
if let Err(e) = self.input_queue_evt.read() {
error!("Failed to get queue event: {:?}", e);
return true;
} else if self.process_input_queue() {
if let Err(e) = self.signal_used_queue() {
error!("Failed to signal used queue: {:?}", e);
return true;
}
}
}
OUTPUT_QUEUE_EVENT => {
if let Err(e) = self.output_queue_evt.read() {
error!("Failed to get queue event: {:?}", e);
return true;
} else {
self.process_output_queue();
}
}
INPUT_EVENT => {
if let Err(e) = self.input_evt.read() {
error!("Failed to get input event: {:?}", e);
return true;
} else if self.process_input_queue() {
if let Err(e) = self.signal_used_queue() {
error!("Failed to signal used queue: {:?}", e);
return true;
}
}
}
CONFIG_EVENT => {
if let Err(e) = self.config_evt.read() {
error!("Failed to get config event: {:?}", e);
return true;
} else if let Err(e) = self
.interrupt_cb
.trigger(&VirtioInterruptType::Config, None)
{
error!("Failed to signal console driver: {:?}", e);
return true;
}
}
_ => {
error!("Unknown event for virtio-console");
return true;
}
}
false
}
}
/// Input device.
pub struct ConsoleInput {
input_evt: EventFd,
config_evt: EventFd,
in_buffer: Arc<Mutex<VecDeque<u8>>>,
config: Arc<Mutex<VirtioConsoleConfig>>,
acked_features: AtomicU64,
}
impl ConsoleInput {
pub fn queue_input_bytes(&self, input: &[u8]) {
let mut in_buffer = self.in_buffer.lock().unwrap();
in_buffer.extend(input);
let _ = self.input_evt.write(1);
}
pub fn update_console_size(&self, cols: u16, rows: u16) {
if self
.acked_features
.fetch_and(1u64 << VIRTIO_CONSOLE_F_SIZE, Ordering::AcqRel)
!= 0
{
self.config.lock().unwrap().update_console_size(cols, rows);
//Send the interrupt to the driver
let _ = self.config_evt.write(1);
}
}
}
impl VirtioConsoleConfig {
pub fn new(cols: u16, rows: u16) -> Self {
VirtioConsoleConfig {
cols,
rows,
max_nr_ports: 1u32,
emerg_wr: 0u32,
}
}
pub fn update_console_size(&mut self, cols: u16, rows: u16) {
self.cols = cols;
self.rows = rows;
}
}
/// Virtio device for exposing console to the guest OS through virtio.
pub struct Console {
common: VirtioCommon,
id: String,
config: Arc<Mutex<VirtioConsoleConfig>>,
input: Arc<ConsoleInput>,
out: Arc<Mutex<Box<dyn io::Write + Send + Sync + 'static>>>,
seccomp_action: SeccompAction,
}
#[derive(Serialize, Deserialize)]
pub struct ConsoleState {
avail_features: u64,
acked_features: u64,
config: VirtioConsoleConfig,
in_buffer: VecDeque<u8>,
}
impl Console {
/// Create a new virtio console device that gets random data from /dev/urandom.
pub fn new(
id: String,
out: Box<dyn io::Write + Send + Sync + 'static>,
cols: u16,
rows: u16,
iommu: bool,
seccomp_action: SeccompAction,
) -> io::Result<(Console, Arc<ConsoleInput>)> {
let mut avail_features = 1u64 << VIRTIO_F_VERSION_1 | 1u64 << VIRTIO_CONSOLE_F_SIZE;
if iommu {
avail_features |= 1u64 << VIRTIO_F_IOMMU_PLATFORM;
}
let input_evt = EventFd::new(EFD_NONBLOCK).unwrap();
let config_evt = EventFd::new(EFD_NONBLOCK).unwrap();
let console_config = Arc::new(Mutex::new(VirtioConsoleConfig::new(cols, rows)));
let console_input = Arc::new(ConsoleInput {
input_evt,
config_evt,
in_buffer: Arc::new(Mutex::new(VecDeque::new())),
config: console_config.clone(),
acked_features: AtomicU64::new(0),
});
Ok((
Console {
common: VirtioCommon {
device_type: VirtioDeviceType::TYPE_CONSOLE as u32,
queue_sizes: QUEUE_SIZES.to_vec(),
avail_features,
paused_sync: Some(Arc::new(Barrier::new(2))),
..Default::default()
},
id,
config: console_config,
input: console_input.clone(),
out: Arc::new(Mutex::new(out)),
seccomp_action,
},
console_input,
))
}
fn state(&self) -> ConsoleState {
ConsoleState {
avail_features: self.common.avail_features,
acked_features: self.common.acked_features,
config: *(self.config.lock().unwrap()),
in_buffer: self.input.in_buffer.lock().unwrap().clone(),
}
}
fn set_state(&mut self, state: &ConsoleState) -> io::Result<()> {
self.common.avail_features = state.avail_features;
self.common.acked_features = state.acked_features;
*(self.config.lock().unwrap()) = state.config;
*(self.input.in_buffer.lock().unwrap()) = state.in_buffer.clone();
Ok(())
}
}
impl Drop for Console {
fn drop(&mut self) {
if let Some(kill_evt) = self.common.kill_evt.take() {
// Ignore the result because there is nothing we can do about it.
let _ = kill_evt.write(1);
}
}
}
impl VirtioDevice for Console {
fn device_type(&self) -> u32 {
self.common.device_type
}
fn queue_max_sizes(&self) -> &[u16] {
&self.common.queue_sizes
}
fn features(&self) -> u64 {
self.common.avail_features
}
fn ack_features(&mut self, value: u64) {
self.common.ack_features(value)
}
fn read_config(&self, offset: u64, data: &mut [u8]) {
self.read_config_from_slice(self.config.lock().unwrap().as_slice(), offset, data);
}
fn activate(
&mut self,
mem: GuestMemoryAtomic<GuestMemoryMmap>,
interrupt_cb: Arc<dyn VirtioInterrupt>,
queues: Vec<Queue>,
mut queue_evts: Vec<EventFd>,
) -> ActivateResult {
self.common.activate(&queues, &queue_evts, &interrupt_cb)?;
self.input
.acked_features
.store(self.common.acked_features, Ordering::Relaxed);
if self.common.feature_acked(VIRTIO_CONSOLE_F_SIZE) {
if let Err(e) = interrupt_cb.trigger(&VirtioInterruptType::Config, None) {
error!("Failed to signal console driver: {:?}", e);
}
}
let kill_evt = self
.common
.kill_evt
.as_ref()
.unwrap()
.try_clone()
.map_err(|e| {
error!("failed to clone kill_evt eventfd: {}", e);
ActivateError::BadActivate
})?;
let pause_evt = self
.common
.pause_evt
.as_ref()
.unwrap()
.try_clone()
.map_err(|e| {
error!("failed to clone pause_evt eventfd: {}", e);
ActivateError::BadActivate
})?;
let mut handler = ConsoleEpollHandler {
queues,
mem,
interrupt_cb,
in_buffer: self.input.in_buffer.clone(),
out: self.out.clone(),
input_queue_evt: queue_evts.remove(0),
output_queue_evt: queue_evts.remove(0),
input_evt: self.input.input_evt.try_clone().unwrap(),
config_evt: self.input.config_evt.try_clone().unwrap(),
kill_evt,
pause_evt,
};
let paused = self.common.paused.clone();
let paused_sync = self.common.paused_sync.clone();
let mut epoll_threads = Vec::new();
// Retrieve seccomp filter for virtio_console thread
let virtio_console_seccomp_filter =
get_seccomp_filter(&self.seccomp_action, Thread::VirtioConsole)
.map_err(ActivateError::CreateSeccompFilter)?;
thread::Builder::new()
.name("virtio_console".to_string())
.spawn(move || {
if let Err(e) = SeccompFilter::apply(virtio_console_seccomp_filter) {
error!("Error applying seccomp filter: {:?}", e);
} else if let Err(e) = handler.run(paused, paused_sync.unwrap()) {
error!("Error running worker: {:?}", e);
}
})
.map(|thread| epoll_threads.push(thread))
.map_err(|e| {
error!("failed to clone the virtio-console epoll thread: {}", e);
ActivateError::BadActivate
})?;
self.common.epoll_threads = Some(epoll_threads);
Ok(())
}
fn reset(&mut self) -> Option<(Arc<dyn VirtioInterrupt>, Vec<EventFd>)> {
self.common.reset()
}
}
impl Pausable for Console {
fn pause(&mut self) -> result::Result<(), MigratableError> {
self.common.pause()
}
fn resume(&mut self) -> result::Result<(), MigratableError> {
self.common.resume()
}
}
impl Snapshottable for Console {
fn id(&self) -> String {
self.id.clone()
}
fn snapshot(&mut self) -> std::result::Result<Snapshot, MigratableError> {
let snapshot =
serde_json::to_vec(&self.state()).map_err(|e| MigratableError::Snapshot(e.into()))?;
let mut console_snapshot = Snapshot::new(self.id.as_str());
console_snapshot.add_data_section(SnapshotDataSection {
id: format!("{}-section", self.id),
snapshot,
});
Ok(console_snapshot)
}
fn restore(&mut self, snapshot: Snapshot) -> std::result::Result<(), MigratableError> {
if let Some(console_section) = snapshot.snapshot_data.get(&format!("{}-section", self.id)) {
let console_state = match serde_json::from_slice(&console_section.snapshot) {
Ok(state) => state,
Err(error) => {
return Err(MigratableError::Restore(anyhow!(
"Could not deserialize CONSOLE {}",
error
)))
}
};
return self.set_state(&console_state).map_err(|e| {
MigratableError::Restore(anyhow!("Could not restore CONSOLE state {:?}", e))
});
}
Err(MigratableError::Restore(anyhow!(
"Could not find CONSOLE snapshot section"
)))
}
}
impl Transportable for Console {}
impl Migratable for Console {}