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devices: net: activate through an activation event
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Postpone net external events registration to device activation time.
This makes the net device unaware of external events prior to
its activation.

During creation register a dedicated activation event which will notify
the device when it's time to register the other external events sources.

This activation event is unregistered after successful device
activation.

Signed-off-by: Adrian Catangiu <acatan@amazon.com>
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@acatangiu
acatangiu committed Mar 19, 2020
1 parent ec157e1 commit ccd1383
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Showing 4 changed files with 203 additions and 88 deletions.
1 change: 1 addition & 0 deletions src/devices/src/lib.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -47,4 +47,5 @@ pub enum Error {
PayloadExpected,
IoError(io::Error),
NoAvailBuffers,
SpuriousEvent,
}
144 changes: 89 additions & 55 deletions src/devices/src/virtio/net/device.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,9 @@
use crate::virtio::net::Error;
use crate::virtio::net::Result;
use crate::virtio::net::{MAX_BUFFER_SIZE, QUEUE_SIZE, QUEUE_SIZES, RX_INDEX, TX_INDEX};
use crate::virtio::{ActivateResult, Queue, VirtioDevice, TYPE_NET, VIRTIO_MMIO_INT_VRING};
use crate::virtio::{
ActivateResult, DeviceState, Queue, VirtioDevice, TYPE_NET, VIRTIO_MMIO_INT_VRING,
};
use crate::{report_net_event_fail, Error as DeviceError};
use dumbo::ns::MmdsNetworkStack;
use dumbo::{EthernetFrame, MacAddr, MAC_ADDR_LEN};
Expand Down Expand Up @@ -59,8 +61,6 @@ pub struct Net {
avail_features: u64,
acked_features: u64,

mem: GuestMemoryMmap,

pub(crate) queues: Vec<Queue>,
pub(crate) queue_evts: Vec<EventFd>,

Expand All @@ -82,7 +82,8 @@ pub struct Net {
config_space: Vec<u8>,
guest_mac: Option<MacAddr>,

device_activated: bool,
pub(crate) device_state: DeviceState,
pub(crate) activate_evt: EventFd,

mmds_ns: Option<MmdsNetworkStack>,

Expand All @@ -95,7 +96,6 @@ impl Net {
pub fn new_with_tap(
tap: Tap,
guest_mac: Option<&MacAddr>,
mem: GuestMemoryMmap,
rx_rate_limiter: RateLimiter,
tx_rate_limiter: RateLimiter,
allow_mmds_requests: bool,
Expand Down Expand Up @@ -148,7 +148,6 @@ impl Net {
tap,
avail_features,
acked_features: 0u64,
mem,
queues,
queue_evts,
rx_rate_limiter,
Expand All @@ -161,7 +160,8 @@ impl Net {
tx_iovec: Vec::with_capacity(QUEUE_SIZE as usize),
interrupt_status: Arc::new(AtomicUsize::new(0)),
interrupt_evt: EventFd::new(libc::EFD_NONBLOCK).map_err(Error::EventFd)?,
device_activated: false,
device_state: DeviceState::Inactive,
activate_evt: EventFd::new(libc::EFD_NONBLOCK).map_err(Error::EventFd)?,
config_space,
guest_mac,
mmds_ns,
Expand Down Expand Up @@ -219,8 +219,13 @@ impl Net {
// 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) -> bool {
let mem = match self.device_state {
DeviceState::Activated(ref mem) => mem,
// This should never happen, it's been already validated in the event handler.
DeviceState::Inactive => return false,
};
let rx_queue = &mut self.queues[RX_INDEX];
let mut next_desc = rx_queue.pop(&self.mem);
let mut next_desc = rx_queue.pop(mem);
if next_desc.is_none() {
return false;
}
Expand All @@ -239,7 +244,7 @@ impl Net {

let limit = cmp::min(write_count + desc.len as usize, self.rx_bytes_read);
let source_slice = &self.rx_frame_buf[write_count..limit];
let write_result = self.mem.write_slice(source_slice, desc.addr);
let write_result = mem.write_slice(source_slice, desc.addr);

match write_result {
Ok(()) => {
Expand Down Expand Up @@ -271,7 +276,7 @@ impl Net {
}
}

rx_queue.add_used(&self.mem, head_index, write_count as u32);
rx_queue.add_used(mem, head_index, write_count as u32);

// Mark that we have at least one pending packet and we need to interrupt the guest.
self.rx_deferred_irqs = true;
Expand Down Expand Up @@ -406,6 +411,12 @@ impl Net {
}

fn process_tx(&mut self) -> result::Result<(), DeviceError> {
let mem = match self.device_state {
DeviceState::Activated(ref mem) => mem,
// This should never happen, it's been already validated in the event handler.
DeviceState::Inactive => return Err(DeviceError::SpuriousEvent),
};

// The MMDS network stack works like a state machine, based on synchronous calls, and
// without being added to any event loop. If any frame is accepted by the MMDS, we also
// trigger a process_rx() which checks if there are any new frames to be sent, starting
Expand All @@ -414,7 +425,7 @@ impl Net {
let mut raise_irq = false;
let tx_queue = &mut self.queues[TX_INDEX];

while let Some(head) = tx_queue.pop(&self.mem) {
while let Some(head) = tx_queue.pop(mem) {
// If limiter.consume() fails it means there is no more TokenType::Ops
// budget and rate limiting is in effect.
if !self.tx_rate_limiter.consume(1, TokenType::Ops) {
Expand Down Expand Up @@ -459,7 +470,7 @@ impl Net {
for (desc_addr, desc_len) in self.tx_iovec.drain(..) {
let limit = cmp::min((read_count + desc_len) as usize, self.tx_frame_buf.len());

let read_result = self.mem.read_slice(
let read_result = mem.read_slice(
&mut self.tx_frame_buf[read_count..limit as usize],
desc_addr,
);
Expand Down Expand Up @@ -492,7 +503,7 @@ impl Net {
process_rx_for_mmds = true;
}

tx_queue.add_used(&self.mem, head_index, 0);
tx_queue.add_used(mem, head_index, 0);
raise_irq = true;
}

Expand Down Expand Up @@ -541,8 +552,13 @@ impl Net {
}

pub fn process_tap_rx_event(&mut self) {
let mem = match self.device_state {
DeviceState::Activated(ref mem) => mem,
// This should never happen, it's been already validated in the event handler.
DeviceState::Inactive => return,
};
METRICS.net.rx_tap_event_count.inc();
if self.queues[RX_INDEX].is_empty(&self.mem) {
if self.queues[RX_INDEX].is_empty(mem) {
error!("The RX queue is empty, there is no available buffer.");
METRICS.net.event_fails.inc();
return;
Expand Down Expand Up @@ -676,11 +692,18 @@ impl VirtioDevice for Net {
}

fn is_activated(&self) -> bool {
self.device_activated
match self.device_state {
DeviceState::Inactive => false,
DeviceState::Activated(_) => true,
}
}

fn activate(&mut self, _: GuestMemoryMmap) -> ActivateResult {
self.device_activated = true;
fn activate(&mut self, mem: GuestMemoryMmap) -> ActivateResult {
if self.activate_evt.write(1).is_err() {
error!("Net: Cannot write to activate_evt");
return Err(super::super::ActivateError::BadActivate);
}
self.device_state = DeviceState::Activated(mem);
Ok(())
}
}
Expand All @@ -690,6 +713,7 @@ mod tests {
use std::net::Ipv4Addr;
use std::os::unix::io::AsRawFd;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::sync::Mutex;
use std::time::Duration;
use std::{io, mem, thread};

Expand Down Expand Up @@ -747,7 +771,7 @@ mod tests {
fn default_guest_memory() -> GuestMemoryMmap;
fn rx_single_frame_no_irq_coalescing(&mut self) -> bool;
fn virtqueues(mem: &GuestMemoryMmap) -> (VirtQueue, VirtQueue);
fn assign_queues(&mut self, rxq: Queue, txq: Queue);
fn assign_queues(&mut self, rxq: Queue, txq: Queue, mem: &GuestMemoryMmap);
fn set_mac(&mut self, mac: MacAddr);
}

Expand All @@ -762,7 +786,6 @@ mod tests {
let mut net = Net::new_with_tap(
tap,
Some(&guest_mac),
Net::default_guest_memory(),
RateLimiter::default(),
RateLimiter::default(),
true,
Expand Down Expand Up @@ -808,11 +831,11 @@ mod tests {
}

// Assigns "guest virtio driver" activated queues to the net device.
fn assign_queues(&mut self, rxq: Queue, txq: Queue) {
fn assign_queues(&mut self, rxq: Queue, txq: Queue, mem: &GuestMemoryMmap) {
self.queues.clear();
self.queues.push(rxq);
self.queues.push(txq);
self.activate(self.mem.clone()).unwrap();
self.activate(mem.clone()).unwrap();
}
}

Expand Down Expand Up @@ -934,9 +957,9 @@ mod tests {
fn test_event_handling() {
let mut event_manager = EventManager::new().unwrap();
let mut net = Net::default_net(TestMutators::default());
let mem_clone = net.mem.clone();
let (rxq, txq) = Net::virtqueues(&mem_clone);
net.assign_queues(rxq.create_queue(), txq.create_queue());
let mem = Net::default_guest_memory();
let (rxq, txq) = Net::virtqueues(&mem);
net.assign_queues(rxq.create_queue(), txq.create_queue(), &mem);

let daddr = 0x2000;
assert!(daddr > txq.end().0);
Expand Down Expand Up @@ -1213,9 +1236,9 @@ mod tests {
fn test_process_error_cases() {
let mut event_manager = EventManager::new().unwrap();
let mut net = Net::default_net(TestMutators::default());
let mem_clone = net.mem.clone();
let (rxq, txq) = Net::virtqueues(&mem_clone);
net.assign_queues(rxq.create_queue(), txq.create_queue());
let mem = Net::default_guest_memory();
let (rxq, txq) = Net::virtqueues(&mem);
net.assign_queues(rxq.create_queue(), txq.create_queue(), &mem);

// RX rate limiter events should error since the limiter is not blocked.
// Validate that the event failed and failure was properly accounted for.
Expand All @@ -1242,15 +1265,26 @@ mod tests {
fn test_invalid_event() {
let mut event_manager = EventManager::new().unwrap();
let mut net = Net::default_net(TestMutators::default());
let mem_clone = net.mem.clone();
let (rxq, txq) = Net::virtqueues(&mem_clone);
net.assign_queues(rxq.create_queue(), txq.create_queue());

let mem = Net::default_guest_memory();
let (rxq, txq) = Net::virtqueues(&mem);
net.assign_queues(rxq.create_queue(), txq.create_queue(), &mem);

let net = Arc::new(Mutex::new(net));
event_manager.add_subscriber(net.clone()).unwrap();

// Process the activate event.
let ev_count = event_manager.run_with_timeout(50).unwrap();
assert_eq!(ev_count, 1);

// Inject invalid event.
let invalid_event = EpollEvent::new(EventSet::IN, 1000);
check_metric_after_block!(
&METRICS.net.event_fails,
1,
net.process(&invalid_event, &mut event_manager)
net.lock()
.unwrap()
.process(&invalid_event, &mut event_manager)
);
}

Expand All @@ -1265,9 +1299,9 @@ mod tests {
};

let mut net = Net::default_net(test_mutators);
let mem_clone = net.mem.clone();
let (rxq, txq) = Net::virtqueues(&mem_clone);
net.assign_queues(rxq.create_queue(), txq.create_queue());
let mem = Net::default_guest_memory();
let (rxq, txq) = Net::virtqueues(&mem);
net.assign_queues(rxq.create_queue(), txq.create_queue(), &mem);

// The RX queue is empty.
let tap_event = EpollEvent::new(EventSet::IN, net.tap.as_raw_fd() as u64);
Expand All @@ -1290,9 +1324,9 @@ mod tests {
fn test_rx_rate_limiter_handling() {
let mut event_manager = EventManager::new().unwrap();
let mut net = Net::default_net(TestMutators::default());
let mem_clone = net.mem.clone();
let (rxq, txq) = Net::virtqueues(&mem_clone);
net.assign_queues(rxq.create_queue(), txq.create_queue());
let mem = Net::default_guest_memory();
let (rxq, txq) = Net::virtqueues(&mem);
net.assign_queues(rxq.create_queue(), txq.create_queue(), &mem);

net.rx_rate_limiter = RateLimiter::new(0, None, 0, 0, None, 0).unwrap();
let rate_limiter_event =
Expand All @@ -1308,9 +1342,9 @@ mod tests {
fn test_tx_rate_limiter_handling() {
let mut event_manager = EventManager::new().unwrap();
let mut net = Net::default_net(TestMutators::default());
let mem_clone = net.mem.clone();
let (rxq, txq) = Net::virtqueues(&mem_clone);
net.assign_queues(rxq.create_queue(), txq.create_queue());
let mem = Net::default_guest_memory();
let (rxq, txq) = Net::virtqueues(&mem);
net.assign_queues(rxq.create_queue(), txq.create_queue(), &mem);

net.tx_rate_limiter = RateLimiter::new(0, None, 0, 0, None, 0).unwrap();
let rate_limiter_event =
Expand All @@ -1327,9 +1361,9 @@ mod tests {
fn test_bandwidth_rate_limiter() {
let mut event_manager = EventManager::new().unwrap();
let mut net = Net::default_net(TestMutators::default());
let mem_clone = net.mem.clone();
let (rxq, txq) = Net::virtqueues(&mem_clone);
net.assign_queues(rxq.create_queue(), txq.create_queue());
let mem = Net::default_guest_memory();
let (rxq, txq) = Net::virtqueues(&mem);
net.assign_queues(rxq.create_queue(), txq.create_queue(), &mem);

let daddr = 0x2000;
assert!(daddr > txq.end().0);
Expand Down Expand Up @@ -1445,9 +1479,9 @@ mod tests {
fn test_ops_rate_limiter() {
let mut event_manager = EventManager::new().unwrap();
let mut net = Net::default_net(TestMutators::default());
let mem_clone = net.mem.clone();
let (rxq, txq) = Net::virtqueues(&mem_clone);
net.assign_queues(rxq.create_queue(), txq.create_queue());
let mem = Net::default_guest_memory();
let (rxq, txq) = Net::virtqueues(&mem);
net.assign_queues(rxq.create_queue(), txq.create_queue(), &mem);

let daddr = 0x2000;
assert!(daddr > txq.end().0);
Expand Down Expand Up @@ -1564,9 +1598,9 @@ mod tests {
#[test]
fn test_patch_rate_limiters() {
let mut net = Net::default_net(TestMutators::default());
let mem_clone = net.mem.clone();
let (rxq, txq) = Net::virtqueues(&mem_clone);
net.assign_queues(rxq.create_queue(), txq.create_queue());
let mem = Net::default_guest_memory();
let (rxq, txq) = Net::virtqueues(&mem);
net.assign_queues(rxq.create_queue(), txq.create_queue(), &mem);

net.rx_rate_limiter = RateLimiter::new(10, None, 10, 2, None, 2).unwrap();
net.tx_rate_limiter = RateLimiter::new(10, None, 10, 2, None, 2).unwrap();
Expand Down Expand Up @@ -1600,9 +1634,9 @@ mod tests {
// Regression test for https://github.com/firecracker-microvm/firecracker/issues/1436 .
let mut event_manager = EventManager::new().unwrap();
let mut net = Net::default_net(TestMutators::default());
let mem_clone = net.mem.clone();
let (rxq, txq) = Net::virtqueues(&mem_clone);
net.assign_queues(rxq.create_queue(), txq.create_queue());
let mem = Net::default_guest_memory();
let (rxq, txq) = Net::virtqueues(&mem);
net.assign_queues(rxq.create_queue(), txq.create_queue(), &mem);

let daddr = 0x2000;
assert!(daddr > txq.end().0);
Expand All @@ -1626,9 +1660,9 @@ mod tests {
#[test]
fn test_virtio_device() {
let mut net = Net::default_net(TestMutators::default());
let mem_clone = net.mem.clone();
let (rxq, txq) = Net::virtqueues(&mem_clone);
net.assign_queues(rxq.create_queue(), txq.create_queue());
let mem = Net::default_guest_memory();
let (rxq, txq) = Net::virtqueues(&mem);
net.assign_queues(rxq.create_queue(), txq.create_queue(), &mem);

// Test queues count (TX and RX).
let queues = net.queues();
Expand Down
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