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virtio-devices: console: Port to EpollHelper

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Migrate to EpollHelper so as to remove code that is duplicated between
multiple virtio devices.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This commit is contained in:
Sebastien Boeuf 2020-08-11 17:38:13 +02:00
parent bdef54ead6
commit d9992b5b5f
1 changed files with 71 additions and 163 deletions
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234
virtio-devices/src/console.rs
View File

@ -3,8 +3,9 @@
use super::Error as DeviceError;
use super::{
ActivateError, ActivateResult, DeviceEventT, Queue, VirtioDevice, VirtioDeviceType,
VirtioInterruptType, VIRTIO_F_IOMMU_PLATFORM, VIRTIO_F_VERSION_1,
ActivateError, ActivateResult, EpollHelper, EpollHelperError, EpollHelperHandler, Queue,
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;
@ -14,11 +15,10 @@ use seccomp::{SeccompAction, SeccompFilter};
use serde::ser::{Serialize, SerializeStruct, Serializer};
use std::cmp;
use std::collections::VecDeque;
use std::fs::File;
use std::io;
use std::io::Write;
use std::ops::DerefMut;
use std::os::unix::io::{AsRawFd, FromRawFd};
use std::os::unix::io::AsRawFd;
use std::result;
use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
use std::sync::{Arc, Mutex};
@ -35,16 +35,12 @@ 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: DeviceEventT = 0;
const OUTPUT_QUEUE_EVENT: DeviceEventT = 1;
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: DeviceEventT = 2;
// The device has been dropped.
const KILL_EVENT: DeviceEventT = 3;
const INPUT_EVENT: u16 = EPOLL_HELPER_EVENT_LAST + 3;
// Console configuration change event is triggered.
const CONFIG_EVENT: DeviceEventT = 4;
// The device should be paused.
const PAUSE_EVENT: DeviceEventT = 5;
const CONFIG_EVENT: u16 = EPOLL_HELPER_EVENT_LAST + 4;
//Console size feature bit
const VIRTIO_CONSOLE_F_SIZE: u64 = 0;
@ -184,158 +180,69 @@ impl ConsoleEpollHandler {
})
}
fn run(&mut self, paused: Arc<AtomicBool>) -> 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) };
fn run(&mut self, paused: Arc<AtomicBool>) -> 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, self)?;
// Add events
epoll::ctl(
epoll_file.as_raw_fd(),
epoll::ControlOptions::EPOLL_CTL_ADD,
self.input_queue_evt.as_raw_fd(),
epoll::Event::new(epoll::Events::EPOLLIN, u64::from(INPUT_QUEUE_EVENT)),
)
.map_err(DeviceError::EpollCtl)?;
epoll::ctl(
epoll_file.as_raw_fd(),
epoll::ControlOptions::EPOLL_CTL_ADD,
self.output_queue_evt.as_raw_fd(),
epoll::Event::new(epoll::Events::EPOLLIN, u64::from(OUTPUT_QUEUE_EVENT)),
)
.map_err(DeviceError::EpollCtl)?;
epoll::ctl(
epoll_file.as_raw_fd(),
epoll::ControlOptions::EPOLL_CTL_ADD,
self.input_evt.as_raw_fd(),
epoll::Event::new(epoll::Events::EPOLLIN, u64::from(INPUT_EVENT)),
)
.map_err(DeviceError::EpollCtl)?;
epoll::ctl(
epoll_file.as_raw_fd(),
epoll::ControlOptions::EPOLL_CTL_ADD,
self.config_evt.as_raw_fd(),
epoll::Event::new(epoll::Events::EPOLLIN, u64::from(CONFIG_EVENT)),
)
.map_err(DeviceError::EpollCtl)?;
Ok(())
}
}
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)?;
const EPOLL_EVENTS_LEN: usize = 100;
let mut events = vec![epoll::Event::new(epoll::Events::empty(), 0); EPOLL_EVENTS_LEN];
// 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 {
INPUT_QUEUE_EVENT => {
if let Err(e) = self.input_queue_evt.read() {
error!("Failed to get queue event: {:?}", e);
break 'epoll;
} else if self.process_input_queue() {
if let Err(e) = self.signal_used_queue() {
error!("Failed to signal used queue: {:?}", e);
break 'epoll;
}
}
}
OUTPUT_QUEUE_EVENT => {
if let Err(e) = self.output_queue_evt.read() {
error!("Failed to get queue event: {:?}", e);
break 'epoll;
} else {
self.process_output_queue();
}
}
INPUT_EVENT => {
if let Err(e) = self.input_evt.read() {
error!("Failed to get input event: {:?}", e);
break 'epoll;
} else if self.process_input_queue() {
if let Err(e) = self.signal_used_queue() {
error!("Failed to signal used queue: {:?}", e);
break 'epoll;
}
}
}
CONFIG_EVENT => {
if let Err(e) = self.config_evt.read() {
error!("Failed to get config event: {:?}", e);
break 'epoll;
} else if let Err(e) = self
.interrupt_cb
.trigger(&VirtioInterruptType::Config, None)
{
error!("Failed to signal console driver: {:?}", e);
}
}
KILL_EVENT => {
debug!("KILL_EVENT received, stopping epoll loop");
break 'epoll;
}
PAUSE_EVENT => {
debug!("PAUSE_EVENT received, pausing virtio-console 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-console");
impl EpollHelperHandler for ConsoleEpollHandler {
fn handle_event(&mut self, _helper: &mut EpollHelper, event: u16) -> bool {
match event {
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;
}
}
Ok(())
false
}
}
@ -396,7 +303,7 @@ pub struct Console {
out: Arc<Mutex<Box<dyn io::Write + Send + Sync + 'static>>>,
queue_evts: Option<Vec<EventFd>>,
interrupt_cb: Option<Arc<dyn VirtioInterrupt>>,
epoll_threads: Option<Vec<thread::JoinHandle<result::Result<(), DeviceError>>>>,
epoll_threads: Option<Vec<thread::JoinHandle<()>>>,
paused: Arc<AtomicBool>,
seccomp_action: SeccompAction,
}
@ -595,10 +502,11 @@ impl VirtioDevice for Console {
thread::Builder::new()
.name("virtio_console".to_string())
.spawn(move || {
SeccompFilter::apply(virtio_console_seccomp_filter)
.map_err(DeviceError::ApplySeccompFilter)?;
handler.run(paused)
if let Err(e) = SeccompFilter::apply(virtio_console_seccomp_filter) {
error!("Error applying seccomp filter: {:?}", e);
} else if let Err(e) = handler.run(paused) {
error!("Error running worker: {:?}", e);
}
})
.map(|thread| epoll_threads.push(thread))
.map_err(|e| {