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virtio-device: block, common: Split out common code

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Split the block device implementation into code that be used in common
between multiple different virtio device implementations.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>
This commit is contained in:
Rob Bradford 2020-09-03 17:39:06 +01:00
parent a9a138460b
commit 3487524950
2 changed files with 171 additions and 93 deletions
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144
virtio-devices/src/block.rs
View File

@ -17,7 +17,6 @@ use crate::seccomp_filters::{get_seccomp_filter, Thread};
use crate::VirtioInterrupt;
use anyhow::anyhow;
use block_util::{build_disk_image_id, Request, RequestType, VirtioBlockConfig};
use libc::EFD_NONBLOCK;
use seccomp::{SeccompAction, SeccompFilter};
use std::collections::HashMap;
use std::io::{self, Read, Seek, SeekFrom, Write};
@ -261,18 +260,10 @@ impl<T: DiskFile> EpollHelperHandler for BlockEpollHandler<T> {
pub struct Block<T: DiskFile> {
common: VirtioCommon,
id: String,
kill_evt: Option<EventFd>,
disk_image: Arc<Mutex<T>>,
disk_path: PathBuf,
disk_nsectors: u64,
config: VirtioBlockConfig,
queue_evts: Option<Vec<EventFd>>,
interrupt_cb: Option<Arc<dyn VirtioInterrupt>>,
epoll_threads: Option<Vec<thread::JoinHandle<()>>>,
pause_evt: Option<EventFd>,
paused: Arc<AtomicBool>,
paused_sync: Arc<Barrier>,
queue_size: Vec<u16>,
writeback: Arc<AtomicBool>,
counters: BlockCounters,
seccomp_action: SeccompAction,
@ -338,22 +329,17 @@ impl<T: DiskFile> Block<T> {
Ok(Block {
common: VirtioCommon {
device_type: VirtioDeviceType::TYPE_BLOCK as u32,
avail_features,
paused_sync: Some(Arc::new(Barrier::new(num_queues + 1))),
queue_sizes: vec![queue_size; num_queues],
..Default::default()
},
id,
kill_evt: None,
disk_image: Arc::new(Mutex::new(disk_image)),
disk_path,
disk_nsectors,
config,
queue_evts: None,
interrupt_cb: None,
epoll_threads: None,
pause_evt: None,
paused: Arc::new(AtomicBool::new(false)),
paused_sync: Arc::new(Barrier::new(num_queues + 1)),
queue_size: vec![queue_size; num_queues],
writeback: Arc::new(AtomicBool::new(true)),
counters: BlockCounters::default(),
seccomp_action,
@ -401,22 +387,13 @@ impl<T: DiskFile> Block<T> {
}
}
impl<T: DiskFile> Drop for Block<T> {
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<T: 'static + DiskFile + Send> VirtioDevice for Block<T> {
fn device_type(&self) -> u32 {
VirtioDeviceType::TYPE_BLOCK as u32
self.common.device_type
}
fn queue_max_sizes(&self) -> &[u16] {
self.queue_size.as_slice()
self.common.queue_sizes.as_slice()
}
fn features(&self) -> u64 {
@ -456,54 +433,35 @@ impl<T: 'static + DiskFile + Send> VirtioDevice for Block<T> {
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);
// 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);
self.common.activate(&queues, &queue_evts, &interrupt_cb)?;
let disk_image_id = build_disk_image_id(&self.disk_path);
let event_idx = self.common.feature_acked(VIRTIO_RING_F_EVENT_IDX.into());
self.update_writeback();
let mut epoll_threads = Vec::new();
for _ in 0..self.queue_size.len() {
for _ in 0..self.common.queue_sizes.len() {
let queue_evt = queue_evts.remove(0);
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 = BlockEpollHandler {
queue: queues.remove(0),
mem: mem.clone(),
@ -511,8 +469,8 @@ impl<T: 'static + DiskFile + Send> VirtioDevice for Block<T> {
disk_nsectors: self.disk_nsectors,
interrupt_cb: interrupt_cb.clone(),
disk_image_id: disk_image_id.clone(),
kill_evt: kill_evt.try_clone().unwrap(),
pause_evt: pause_evt.try_clone().unwrap(),
kill_evt,
pause_evt,
event_idx,
writeback: self.writeback.clone(),
counters: self.counters.clone(),
@ -521,8 +479,8 @@ impl<T: 'static + DiskFile + Send> VirtioDevice for Block<T> {
handler.queue.set_event_idx(event_idx);
let paused = self.paused.clone();
let paused_sync = self.paused_sync.clone();
let paused = self.common.paused.clone();
let paused_sync = self.common.paused_sync.clone();
// Retrieve seccomp filter for virtio_blk thread
let virtio_blk_seccomp_filter =
@ -534,7 +492,7 @@ impl<T: 'static + DiskFile + Send> VirtioDevice for Block<T> {
.spawn(move || {
if let Err(e) = SeccompFilter::apply(virtio_blk_seccomp_filter) {
error!("Error applying seccomp filter: {:?}", e);
} else if let Err(e) = handler.run(paused, paused_sync) {
} else if let Err(e) = handler.run(paused, paused_sync.unwrap()) {
error!("Error running worker: {:?}", e);
}
})
@ -545,27 +503,13 @@ impl<T: 'static + DiskFile + Send> VirtioDevice for Block<T> {
})?;
}
self.epoll_threads = Some(epoll_threads);
self.common.epoll_threads = Some(epoll_threads);
Ok(())
}
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(),
))
self.common.reset()
}
fn counters(&self) -> Option<HashMap<&'static str, Wrapping<u64>>> {
@ -592,7 +536,25 @@ impl<T: 'static + DiskFile + Send> VirtioDevice for Block<T> {
}
}
virtio_pausable!(Block, T: 'static + DiskFile + Send);
impl<T: DiskFile> Drop for Block<T> {
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<T: 'static + DiskFile + Send> Pausable for Block<T> {
fn pause(&mut self) -> result::Result<(), MigratableError> {
self.common.pause()
}
fn resume(&mut self) -> result::Result<(), MigratableError> {
self.common.resume()
}
}
impl<T: 'static + DiskFile + Send> Snapshottable for Block<T> {
fn id(&self) -> String {
self.id.clone()

120
virtio-devices/src/device.rs
View File

@ -6,12 +6,18 @@
//
// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
use crate::{ActivateResult, Error, Queue};
use crate::{ActivateError, ActivateResult, Error, Queue};
use libc::EFD_NONBLOCK;
use std::collections::HashMap;
use std::io::Write;
use std::num::Wrapping;
use std::sync::Arc;
use std::sync::{
atomic::{AtomicBool, Ordering},
Arc, Barrier,
};
use std::thread;
use vm_memory::{GuestAddress, GuestMemoryAtomic, GuestMemoryMmap, GuestUsize};
use vm_migration::{MigratableError, Pausable};
use vm_virtio::VirtioDeviceType;
use vmm_sys_util::eventfd::EventFd;
@ -187,6 +193,15 @@ pub trait DmaRemapping: Send + Sync {
pub struct VirtioCommon {
pub avail_features: u64,
pub acked_features: u64,
pub kill_evt: Option<EventFd>,
pub interrupt_cb: Option<Arc<dyn VirtioInterrupt>>,
pub queue_evts: Option<Vec<EventFd>>,
pub pause_evt: Option<EventFd>,
pub paused: Arc<AtomicBool>,
pub paused_sync: Option<Arc<Barrier>>,
pub epoll_threads: Option<Vec<thread::JoinHandle<()>>>,
pub queue_sizes: Vec<u16>,
pub device_type: u32,
}
impl VirtioCommon {
@ -206,6 +221,107 @@ impl VirtioCommon {
}
self.acked_features |= v;
}
pub fn activate(
&mut self,
queues: &[Queue],
queue_evts: &[EventFd],
interrupt_cb: &Arc<dyn VirtioInterrupt>,
) -> ActivateResult {
if queues.len() != self.queue_sizes.len() || queue_evts.len() != self.queue_sizes.len() {
error!(
"Cannot perform activate. Expected {} queue(s), got {}",
self.queue_sizes.len(),
queues.len()
);
return Err(ActivateError::BadActivate);
}
let kill_evt = EventFd::new(EFD_NONBLOCK).map_err(|e| {
error!("failed creating kill EventFd: {}", e);
ActivateError::BadActivate
})?;
self.kill_evt = Some(kill_evt);
let pause_evt = EventFd::new(EFD_NONBLOCK).map_err(|e| {
error!("failed creating pause EventFd: {}", e);
ActivateError::BadActivate
})?;
self.pause_evt = Some(pause_evt);
// 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);
Ok(())
}
pub 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(),
))
}
}
impl Pausable for VirtioCommon {
fn pause(&mut self) -> std::result::Result<(), MigratableError> {
debug!(
"Pausing virtio-{}",
VirtioDeviceType::from(self.device_type)
);
self.paused.store(true, Ordering::SeqCst);
if let Some(pause_evt) = &self.pause_evt {
pause_evt
.write(1)
.map_err(|e| MigratableError::Pause(e.into()))?;
// Wait for all threads to acknowledge the pause before going
// any further. This is exclusively performed when pause_evt
// eventfd is Some(), as this means the virtio device has been
// activated. One specific case where the device can be paused
// while it hasn't been yet activated is snapshot/restore.
self.paused_sync.as_ref().unwrap().wait();
}
Ok(())
}
fn resume(&mut self) -> std::result::Result<(), MigratableError> {
debug!(
"Resuming virtio-{}",
VirtioDeviceType::from(self.device_type)
);
self.paused.store(false, Ordering::SeqCst);
if let Some(epoll_threads) = &self.epoll_threads {
for t in epoll_threads.iter() {
t.thread().unpark();
}
}
Ok(())
}
}
#[macro_export]