cloud-hypervisor/virtio-devices/src/net.rs
Rob Bradford 2a6eb31d5b vm-virtio, virtio-devices: Split device implementation from virt queues
Split the generic virtio code (queues and device type) from the
VirtioDevice trait, transport and device implementations.

This also simplifies the feature handling in vhost_user_backend as the
vm-virtio crate is no longer has any features.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>
2020-07-02 17:09:28 +01:00

814 lines
28 KiB
Rust

// Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
//
// Portions Copyright 2017 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the THIRD-PARTY file.
use super::net_util::{
build_net_config_space, build_net_config_space_with_mq, open_tap, register_listener,
unregister_listener, CtrlVirtio, NetCtrlEpollHandler, RxVirtio, TxVirtio, VirtioNetConfig,
KILL_EVENT, NET_EVENTS_COUNT, PAUSE_EVENT, RX_QUEUE_EVENT, RX_TAP_EVENT, TX_QUEUE_EVENT,
};
use super::Error as DeviceError;
use super::{
ActivateError, ActivateResult, Queue, VirtioDevice, VirtioDeviceType, VirtioInterruptType,
};
use crate::VirtioInterrupt;
use anyhow::anyhow;
use libc::EAGAIN;
use libc::EFD_NONBLOCK;
use net_util::{MacAddr, Tap};
use std::cmp;
use std::collections::HashMap;
use std::fs::File;
use std::io::Read;
use std::io::{self, Write};
use std::net::Ipv4Addr;
use std::num::Wrapping;
use std::os::unix::io::{AsRawFd, FromRawFd, RawFd};
use std::result;
use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
use std::sync::Arc;
use std::thread;
use std::vec::Vec;
use virtio_bindings::bindings::virtio_net::*;
use virtio_bindings::bindings::virtio_ring::VIRTIO_RING_F_EVENT_IDX;
use vm_memory::{ByteValued, GuestAddressSpace, GuestMemoryAtomic, GuestMemoryMmap};
use vm_migration::{
Migratable, MigratableError, Pausable, Snapshot, SnapshotDataSection, Snapshottable,
Transportable,
};
use vmm_sys_util::eventfd::EventFd;
#[derive(Debug)]
pub enum Error {
/// Failed to open taps.
OpenTap(super::net_util::Error),
}
pub type Result<T> = result::Result<T, Error>;
pub struct NetQueuePair {
pub mem: Option<GuestMemoryAtomic<GuestMemoryMmap>>,
pub tap: Tap,
pub rx: RxVirtio,
pub tx: TxVirtio,
pub epoll_fd: Option<RawFd>,
pub rx_tap_listening: bool,
pub counters: NetCounters,
}
impl NetQueuePair {
// Copies a single frame from `self.rx.frame_buf` into the guest. Returns true
// if a buffer was used, and false if the frame must be deferred until a buffer
// is made available by the driver.
fn rx_single_frame(&mut self, mut queue: &mut Queue) -> result::Result<bool, DeviceError> {
let mem = self
.mem
.as_ref()
.ok_or(DeviceError::NoMemoryConfigured)
.map(|m| m.memory())?;
let next_desc = queue.iter(&mem).next();
if next_desc.is_none() {
// Queue has no available descriptors
if self.rx_tap_listening {
unregister_listener(
self.epoll_fd.unwrap(),
self.tap.as_raw_fd(),
epoll::Events::EPOLLIN,
u64::from(RX_TAP_EVENT),
)
.map_err(DeviceError::UnregisterListener)?;
self.rx_tap_listening = false;
info!("Listener unregistered");
}
return Ok(false);
}
Ok(self.rx.process_desc_chain(&mem, next_desc, &mut queue))
}
fn process_rx(&mut self, queue: &mut Queue) -> result::Result<bool, DeviceError> {
// Read as many frames as possible.
loop {
match self.read_tap() {
Ok(count) => {
self.rx.bytes_read = count;
if !self.rx_single_frame(queue)? {
self.rx.deferred_frame = true;
break;
}
}
Err(e) => {
// The tap device is non-blocking, so any error aside from EAGAIN is
// unexpected.
match e.raw_os_error() {
Some(err) if err == EAGAIN => (),
_ => {
error!("Failed to read tap: {:?}", e);
return Err(DeviceError::FailedReadTap);
}
};
break;
}
}
}
// Consume the counters from the Rx/Tx queues and accumulate into
// the counters for the device as whole. This consumption is needed
// to handle MQ.
self.counters
.rx_bytes
.fetch_add(self.rx.counter_bytes.0, Ordering::AcqRel);
self.counters
.rx_frames
.fetch_add(self.rx.counter_frames.0, Ordering::AcqRel);
self.rx.counter_bytes = Wrapping(0);
self.rx.counter_frames = Wrapping(0);
if self.rx.deferred_irqs {
self.rx.deferred_irqs = false;
let mem = self
.mem
.as_ref()
.ok_or(DeviceError::NoMemoryConfigured)
.map(|m| m.memory())?;
Ok(queue.needs_notification(&mem, queue.next_used))
} else {
Ok(false)
}
}
pub fn resume_rx(&mut self, queue: &mut Queue) -> result::Result<bool, DeviceError> {
if !self.rx_tap_listening {
register_listener(
self.epoll_fd.unwrap(),
self.tap.as_raw_fd(),
epoll::Events::EPOLLIN,
u64::from(RX_TAP_EVENT),
)
.map_err(DeviceError::RegisterListener)?;
self.rx_tap_listening = true;
info!("Listener registered");
}
if self.rx.deferred_frame {
if self.rx_single_frame(queue)? {
self.rx.deferred_frame = false;
// process_rx() was interrupted possibly before consuming all
// packets in the tap; try continuing now.
self.process_rx(queue)
} else if self.rx.deferred_irqs {
self.rx.deferred_irqs = false;
let mem = self
.mem
.as_ref()
.ok_or(DeviceError::NoMemoryConfigured)
.map(|m| m.memory())?;
Ok(queue.needs_notification(&mem, queue.next_used))
} else {
Ok(false)
}
} else {
Ok(false)
}
}
pub fn process_tx(&mut self, mut queue: &mut Queue) -> result::Result<bool, DeviceError> {
let mem = self
.mem
.as_ref()
.ok_or(DeviceError::NoMemoryConfigured)
.map(|m| m.memory())?;
self.tx.process_desc_chain(&mem, &mut self.tap, &mut queue);
self.counters
.tx_bytes
.fetch_add(self.tx.counter_bytes.0, Ordering::AcqRel);
self.counters
.tx_frames
.fetch_add(self.tx.counter_frames.0, Ordering::AcqRel);
self.tx.counter_bytes = Wrapping(0);
self.tx.counter_frames = Wrapping(0);
Ok(queue.needs_notification(&mem, queue.next_used))
}
pub fn process_rx_tap(&mut self, mut queue: &mut Queue) -> result::Result<bool, DeviceError> {
if self.rx.deferred_frame
// Process a deferred frame first if available. Don't read from tap again
// until we manage to receive this deferred frame.
{
if self.rx_single_frame(&mut queue)? {
self.rx.deferred_frame = false;
self.process_rx(&mut queue)
} else if self.rx.deferred_irqs {
self.rx.deferred_irqs = false;
Ok(true)
} else {
Ok(false)
}
} else {
self.process_rx(&mut queue)
}
}
fn read_tap(&mut self) -> io::Result<usize> {
self.tap.read(&mut self.rx.frame_buf)
}
}
struct NetEpollHandler {
net: NetQueuePair,
interrupt_cb: Arc<dyn VirtioInterrupt>,
kill_evt: EventFd,
pause_evt: EventFd,
// Always generate interrupts until the driver has signalled to the device.
// This mitigates a problem with interrupts from tap events being "lost" upon
// a restore as the vCPU thread isn't ready to handle the interrupt. This causes
// issues when combined with VIRTIO_RING_F_EVENT_IDX interrupt suppression.
driver_awake: bool,
}
impl NetEpollHandler {
fn signal_used_queue(&self, queue: &Queue) -> result::Result<(), DeviceError> {
self.interrupt_cb
.trigger(&VirtioInterruptType::Queue, Some(queue))
.map_err(|e| {
error!("Failed to signal used queue: {:?}", e);
DeviceError::FailedSignalingUsedQueue(e)
})
}
fn handle_rx_event(
&mut self,
mut queue: &mut Queue,
queue_evt: &EventFd,
) -> result::Result<(), DeviceError> {
if let Err(e) = queue_evt.read() {
error!("Failed to get rx queue event: {:?}", e);
}
if self.net.resume_rx(&mut queue)? || !self.driver_awake {
self.signal_used_queue(queue)?;
info!("Signalling RX queue");
} else {
info!("Not signalling RX queue");
}
Ok(())
}
fn handle_tx_event(
&mut self,
mut queue: &mut Queue,
queue_evt: &EventFd,
) -> result::Result<(), DeviceError> {
if let Err(e) = queue_evt.read() {
error!("Failed to get tx queue event: {:?}", e);
}
if self.net.process_tx(&mut queue)? || !self.driver_awake {
self.signal_used_queue(queue)?;
info!("Signalling TX queue");
} else {
info!("Not signalling TX queue");
}
Ok(())
}
fn handle_rx_tap_event(&mut self, queue: &mut Queue) -> result::Result<(), DeviceError> {
if self.net.process_rx_tap(queue)? || !self.driver_awake {
self.signal_used_queue(queue)?;
info!("Signalling RX queue");
} else {
info!("Not signalling RX queue");
}
Ok(())
}
fn run(
&mut self,
paused: Arc<AtomicBool>,
mut queues: Vec<Queue>,
queue_evts: Vec<EventFd>,
) -> result::Result<(), DeviceError> {
// Create the epoll file descriptor
let epoll_fd = epoll::create(true).map_err(DeviceError::EpollCreateFd)?;
// Use 'File' to enforce closing on 'epoll_fd'
let epoll_file = unsafe { File::from_raw_fd(epoll_fd) };
self.net.epoll_fd = Some(epoll_fd);
// Add events
epoll::ctl(
epoll_file.as_raw_fd(),
epoll::ControlOptions::EPOLL_CTL_ADD,
queue_evts[0].as_raw_fd(),
epoll::Event::new(epoll::Events::EPOLLIN, u64::from(RX_QUEUE_EVENT)),
)
.map_err(DeviceError::EpollCtl)?;
epoll::ctl(
epoll_file.as_raw_fd(),
epoll::ControlOptions::EPOLL_CTL_ADD,
queue_evts[1].as_raw_fd(),
epoll::Event::new(epoll::Events::EPOLLIN, u64::from(TX_QUEUE_EVENT)),
)
.map_err(DeviceError::EpollCtl)?;
epoll::ctl(
epoll_file.as_raw_fd(),
epoll::ControlOptions::EPOLL_CTL_ADD,
self.kill_evt.as_raw_fd(),
epoll::Event::new(epoll::Events::EPOLLIN, u64::from(KILL_EVENT)),
)
.map_err(DeviceError::EpollCtl)?;
epoll::ctl(
epoll_file.as_raw_fd(),
epoll::ControlOptions::EPOLL_CTL_ADD,
self.pause_evt.as_raw_fd(),
epoll::Event::new(epoll::Events::EPOLLIN, u64::from(PAUSE_EVENT)),
)
.map_err(DeviceError::EpollCtl)?;
// If there are some already available descriptors on the RX queue,
// then we can start the thread while listening onto the TAP.
if queues[0]
.available_descriptors(&self.net.mem.as_ref().unwrap().memory())
.unwrap()
{
epoll::ctl(
epoll_file.as_raw_fd(),
epoll::ControlOptions::EPOLL_CTL_ADD,
self.net.tap.as_raw_fd(),
epoll::Event::new(epoll::Events::EPOLLIN, u64::from(RX_TAP_EVENT)),
)
.map_err(DeviceError::EpollCtl)?;
self.net.rx_tap_listening = true;
error!("Listener registered at start");
}
let mut events = vec![epoll::Event::new(epoll::Events::empty(), 0); NET_EVENTS_COUNT];
// Before jumping into the epoll loop, check if the device is expected
// to be in a paused state. This is helpful for the restore code path
// as the device thread should not start processing anything before the
// device has been resumed.
while paused.load(Ordering::SeqCst) {
thread::park();
}
'epoll: loop {
let num_events = match epoll::wait(epoll_file.as_raw_fd(), -1, &mut events[..]) {
Ok(res) => res,
Err(e) => {
if e.kind() == io::ErrorKind::Interrupted {
// It's well defined from the epoll_wait() syscall
// documentation that the epoll loop can be interrupted
// before any of the requested events occurred or the
// timeout expired. In both those cases, epoll_wait()
// returns an error of type EINTR, but this should not
// be considered as a regular error. Instead it is more
// appropriate to retry, by calling into epoll_wait().
continue;
}
return Err(DeviceError::EpollWait(e));
}
};
for event in events.iter().take(num_events) {
let ev_type = event.data as u16;
match ev_type {
RX_QUEUE_EVENT => {
self.driver_awake = true;
self.handle_rx_event(&mut queues[0], &queue_evts[0])?;
}
TX_QUEUE_EVENT => {
self.driver_awake = true;
self.handle_tx_event(&mut queues[1], &queue_evts[1])?;
}
RX_TAP_EVENT => {
self.handle_rx_tap_event(&mut queues[0])?;
}
KILL_EVENT => {
debug!("KILL_EVENT received, stopping epoll loop");
break 'epoll;
}
PAUSE_EVENT => {
debug!("PAUSE_EVENT received, pausing virtio-net epoll loop");
// We loop here to handle spurious park() returns.
// Until we have not resumed, the paused boolean will
// be true.
while paused.load(Ordering::SeqCst) {
thread::park();
}
// Drain pause event after the device has been resumed.
// This ensures the pause event has been seen by each
// and every thread related to this virtio device.
let _ = self.pause_evt.read();
}
_ => {
error!("Unknown event for virtio-net");
}
}
}
}
Ok(())
}
}
#[derive(Default, Clone)]
pub struct NetCounters {
tx_bytes: Arc<AtomicU64>,
tx_frames: Arc<AtomicU64>,
rx_bytes: Arc<AtomicU64>,
rx_frames: Arc<AtomicU64>,
}
pub struct Net {
id: String,
kill_evt: Option<EventFd>,
pause_evt: Option<EventFd>,
taps: Option<Vec<Tap>>,
avail_features: u64,
acked_features: u64,
config: VirtioNetConfig,
queue_evts: Option<Vec<EventFd>>,
interrupt_cb: Option<Arc<dyn VirtioInterrupt>>,
epoll_threads: Option<Vec<thread::JoinHandle<result::Result<(), DeviceError>>>>,
ctrl_queue_epoll_thread: Option<thread::JoinHandle<result::Result<(), DeviceError>>>,
paused: Arc<AtomicBool>,
queue_size: Vec<u16>,
counters: NetCounters,
}
#[derive(Serialize, Deserialize)]
pub struct NetState {
pub avail_features: u64,
pub acked_features: u64,
pub config: VirtioNetConfig,
pub queue_size: Vec<u16>,
}
impl Net {
/// Create a new virtio network device with the given TAP interface.
pub fn new_with_tap(
id: String,
taps: Vec<Tap>,
guest_mac: Option<MacAddr>,
iommu: bool,
num_queues: usize,
queue_size: u16,
) -> Result<Self> {
let mut avail_features = 1 << VIRTIO_NET_F_GUEST_CSUM
| 1 << VIRTIO_NET_F_CSUM
| 1 << VIRTIO_NET_F_GUEST_TSO4
| 1 << VIRTIO_NET_F_GUEST_UFO
| 1 << VIRTIO_NET_F_HOST_TSO4
| 1 << VIRTIO_NET_F_HOST_UFO
| 1 << VIRTIO_RING_F_EVENT_IDX
| 1 << VIRTIO_F_VERSION_1;
if iommu {
avail_features |= 1u64 << VIRTIO_F_IOMMU_PLATFORM;
}
avail_features |= 1 << VIRTIO_NET_F_CTRL_VQ;
let queue_num = num_queues + 1;
let mut config = VirtioNetConfig::default();
if let Some(mac) = guest_mac {
build_net_config_space(&mut config, mac, num_queues, &mut avail_features);
} else {
build_net_config_space_with_mq(&mut config, num_queues, &mut avail_features);
}
Ok(Net {
id,
kill_evt: None,
pause_evt: None,
taps: Some(taps),
avail_features,
acked_features: 0u64,
config,
queue_evts: None,
interrupt_cb: None,
epoll_threads: None,
ctrl_queue_epoll_thread: None,
paused: Arc::new(AtomicBool::new(false)),
queue_size: vec![queue_size; queue_num],
counters: NetCounters::default(),
})
}
/// Create a new virtio network device with the given IP address and
/// netmask.
#[allow(clippy::too_many_arguments)]
pub fn new(
id: String,
if_name: Option<&str>,
ip_addr: Option<Ipv4Addr>,
netmask: Option<Ipv4Addr>,
guest_mac: Option<MacAddr>,
host_mac: &mut Option<MacAddr>,
iommu: bool,
num_queues: usize,
queue_size: u16,
) -> Result<Self> {
let taps = open_tap(if_name, ip_addr, netmask, host_mac, num_queues / 2)
.map_err(Error::OpenTap)?;
Self::new_with_tap(id, taps, guest_mac, iommu, num_queues, queue_size)
}
fn state(&self) -> NetState {
NetState {
avail_features: self.avail_features,
acked_features: self.acked_features,
config: self.config,
queue_size: self.queue_size.clone(),
}
}
fn set_state(&mut self, state: &NetState) -> Result<()> {
self.avail_features = state.avail_features;
self.acked_features = state.acked_features;
self.config = state.config;
self.queue_size = state.queue_size.clone();
Ok(())
}
}
impl Drop for Net {
fn drop(&mut self) {
if let Some(kill_evt) = self.kill_evt.take() {
// Ignore the result because there is nothing we can do about it.
let _ = kill_evt.write(1);
}
}
}
impl VirtioDevice for Net {
fn device_type(&self) -> u32 {
VirtioDeviceType::TYPE_NET as u32
}
fn queue_max_sizes(&self) -> &[u16] {
&self.queue_size.as_slice()
}
fn features(&self) -> u64 {
self.avail_features
}
fn ack_features(&mut self, value: u64) {
let mut v = value;
// Check if the guest is ACK'ing a feature that we didn't claim to have.
let unrequested_features = v & !self.avail_features;
if unrequested_features != 0 {
warn!("Received acknowledge request for unknown feature: {:x}", v);
// Don't count these features as acked.
v &= !unrequested_features;
}
self.acked_features |= v;
}
fn read_config(&self, offset: u64, mut data: &mut [u8]) {
let config_slice = self.config.as_slice();
let config_len = config_slice.len() as u64;
if offset >= config_len {
error!("Failed to read config space");
return;
}
if let Some(end) = offset.checked_add(data.len() as u64) {
// This write can't fail, offset and end are checked against config_len.
data.write_all(&config_slice[offset as usize..cmp::min(end, config_len) as usize])
.unwrap();
}
}
fn write_config(&mut self, offset: u64, data: &[u8]) {
let config_slice = self.config.as_mut_slice();
let data_len = data.len() as u64;
let config_len = config_slice.len() as u64;
if offset + data_len > config_len {
error!("Failed to write config space");
return;
}
let (_, right) = config_slice.split_at_mut(offset as usize);
right.copy_from_slice(&data[..]);
}
fn activate(
&mut self,
mem: GuestMemoryAtomic<GuestMemoryMmap>,
interrupt_cb: Arc<dyn VirtioInterrupt>,
mut queues: Vec<Queue>,
mut queue_evts: Vec<EventFd>,
) -> ActivateResult {
if queues.len() != self.queue_size.len() || queue_evts.len() != self.queue_size.len() {
error!(
"Cannot perform activate. Expected {} queue(s), got {}",
self.queue_size.len(),
queues.len()
);
return Err(ActivateError::BadActivate);
}
let (self_kill_evt, kill_evt) = EventFd::new(EFD_NONBLOCK)
.and_then(|e| Ok((e.try_clone()?, e)))
.map_err(|e| {
error!("failed creating kill EventFd pair: {}", e);
ActivateError::BadActivate
})?;
self.kill_evt = Some(self_kill_evt);
let (self_pause_evt, pause_evt) = EventFd::new(EFD_NONBLOCK)
.and_then(|e| Ok((e.try_clone()?, e)))
.map_err(|e| {
error!("failed creating pause EventFd pair: {}", e);
ActivateError::BadActivate
})?;
self.pause_evt = Some(self_pause_evt);
if let Some(mut taps) = self.taps.clone() {
// Save the interrupt EventFD as we need to return it on reset
// but clone it to pass into the thread.
self.interrupt_cb = Some(interrupt_cb.clone());
let mut tmp_queue_evts: Vec<EventFd> = Vec::new();
for queue_evt in queue_evts.iter() {
// Save the queue EventFD as we need to return it on reset
// but clone it to pass into the thread.
tmp_queue_evts.push(queue_evt.try_clone().map_err(|e| {
error!("failed to clone queue EventFd: {}", e);
ActivateError::BadActivate
})?);
}
self.queue_evts = Some(tmp_queue_evts);
let queue_num = queues.len();
if (self.acked_features & 1 << VIRTIO_NET_F_CTRL_VQ) != 0 && queue_num % 2 != 0 {
let cvq_queue = queues.remove(queue_num - 1);
let cvq_queue_evt = queue_evts.remove(queue_num - 1);
let mut ctrl_handler = NetCtrlEpollHandler {
mem: mem.clone(),
kill_evt: kill_evt.try_clone().unwrap(),
pause_evt: pause_evt.try_clone().unwrap(),
ctrl_q: CtrlVirtio::new(cvq_queue, cvq_queue_evt),
epoll_fd: 0,
};
let paused = self.paused.clone();
thread::Builder::new()
.name("virtio_net".to_string())
.spawn(move || ctrl_handler.run_ctrl(paused))
.map(|thread| self.ctrl_queue_epoll_thread = Some(thread))
.map_err(|e| {
error!("failed to clone queue EventFd: {}", e);
ActivateError::BadActivate
})?;
}
let event_idx = self.acked_features & 1 << VIRTIO_RING_F_EVENT_IDX != 0;
let mut epoll_threads = Vec::new();
for _ in 0..taps.len() {
let rx = RxVirtio::new();
let tx = TxVirtio::new();
let rx_tap_listening = false;
let mut queue_pair = Vec::new();
queue_pair.push(queues.remove(0));
queue_pair.push(queues.remove(0));
queue_pair[0].set_event_idx(event_idx);
queue_pair[1].set_event_idx(event_idx);
let mut queue_evt_pair = Vec::new();
queue_evt_pair.push(queue_evts.remove(0));
queue_evt_pair.push(queue_evts.remove(0));
let mut handler = NetEpollHandler {
net: NetQueuePair {
mem: Some(mem.clone()),
tap: taps.remove(0),
rx,
tx,
epoll_fd: None,
rx_tap_listening,
counters: self.counters.clone(),
},
interrupt_cb: interrupt_cb.clone(),
kill_evt: kill_evt.try_clone().unwrap(),
pause_evt: pause_evt.try_clone().unwrap(),
driver_awake: false,
};
let paused = self.paused.clone();
thread::Builder::new()
.name("virtio_net".to_string())
.spawn(move || handler.run(paused, queue_pair, queue_evt_pair))
.map(|thread| epoll_threads.push(thread))
.map_err(|e| {
error!("failed to clone queue EventFd: {}", e);
ActivateError::BadActivate
})?;
}
self.epoll_threads = Some(epoll_threads);
return Ok(());
}
Err(ActivateError::BadActivate)
}
fn reset(&mut self) -> Option<(Arc<dyn VirtioInterrupt>, Vec<EventFd>)> {
// We first must resume the virtio thread if it was paused.
if self.pause_evt.take().is_some() {
self.resume().ok()?;
}
if let Some(kill_evt) = self.kill_evt.take() {
// Ignore the result because there is nothing we can do about it.
let _ = kill_evt.write(1);
}
// Return the interrupt and queue EventFDs
Some((
self.interrupt_cb.take().unwrap(),
self.queue_evts.take().unwrap(),
))
}
fn counters(&self) -> Option<HashMap<&'static str, Wrapping<u64>>> {
let mut counters = HashMap::new();
counters.insert(
"rx_bytes",
Wrapping(self.counters.rx_bytes.load(Ordering::Acquire)),
);
counters.insert(
"rx_frames",
Wrapping(self.counters.rx_frames.load(Ordering::Acquire)),
);
counters.insert(
"tx_bytes",
Wrapping(self.counters.tx_bytes.load(Ordering::Acquire)),
);
counters.insert(
"tx_frames",
Wrapping(self.counters.tx_frames.load(Ordering::Acquire)),
);
Some(counters)
}
}
virtio_ctrl_q_pausable!(Net);
impl Snapshottable for Net {
fn id(&self) -> String {
self.id.clone()
}
fn snapshot(&self) -> std::result::Result<Snapshot, MigratableError> {
let snapshot =
serde_json::to_vec(&self.state()).map_err(|e| MigratableError::Snapshot(e.into()))?;
let mut net_snapshot = Snapshot::new(self.id.as_str());
net_snapshot.add_data_section(SnapshotDataSection {
id: format!("{}-section", self.id),
snapshot,
});
Ok(net_snapshot)
}
fn restore(&mut self, snapshot: Snapshot) -> std::result::Result<(), MigratableError> {
if let Some(net_section) = snapshot.snapshot_data.get(&format!("{}-section", self.id)) {
let net_state = match serde_json::from_slice(&net_section.snapshot) {
Ok(state) => state,
Err(error) => {
return Err(MigratableError::Restore(anyhow!(
"Could not deserialize NET {}",
error
)))
}
};
return self.set_state(&net_state).map_err(|e| {
MigratableError::Restore(anyhow!("Could not restore NET state {:?}", e))
});
}
Err(MigratableError::Restore(anyhow!(
"Could not find NET snapshot section"
)))
}
}
impl Transportable for Net {}
impl Migratable for Net {}