Skip to content

fix(net): Apply only supported TAP offloading features #4386

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 1 commit into from
Closed

fix(net): Apply only supported TAP offloading features #4386

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 4 additions & 0 deletions src/vmm/src/devices/virtio/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,8 @@
use std::any::Any;
use std::io::Error as IOError;

use crate::devices::virtio::net::TapError;

pub mod balloon;
pub mod block_common;
pub mod device;
Expand Down Expand Up @@ -68,6 +70,8 @@ pub enum ActivateError {
BadActivate,
/// Vhost user: {0}
VhostUser(vhost_user::VhostUserError),
/// Setting tap interface offload flags failed: {0}
TapSetOffload(TapError),
}

/// Trait that helps in upcasting an object to Any
Expand Down
96 changes: 88 additions & 8 deletions src/vmm/src/devices/virtio/net/device.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -23,8 +23,10 @@ use vm_memory::GuestMemoryError;
use crate::devices::virtio::device::{DeviceState, IrqTrigger, IrqType, VirtioDevice};
use crate::devices::virtio::gen::virtio_blk::VIRTIO_F_VERSION_1;
use crate::devices::virtio::gen::virtio_net::{
virtio_net_hdr_v1, VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, VIRTIO_NET_F_GUEST_TSO4,
VIRTIO_NET_F_GUEST_UFO, VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_MAC,
virtio_net_hdr_v1, VIRTIO_NET_F_CSUM, VIRTIO_NET_F_GUEST_CSUM, VIRTIO_NET_F_GUEST_ECN,
VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6, VIRTIO_NET_F_GUEST_UFO,
VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_TSO6, VIRTIO_NET_F_HOST_UFO,
VIRTIO_NET_F_MAC,
};
use crate::devices::virtio::gen::virtio_ring::VIRTIO_RING_F_EVENT_IDX;
use crate::devices::virtio::iovec::IoVecBuffer;
Expand Down Expand Up @@ -160,7 +162,11 @@ impl Net {
| 1 << VIRTIO_NET_F_HOST_TSO4
| 1 << VIRTIO_NET_F_HOST_UFO
| 1 << VIRTIO_F_VERSION_1
| 1 << VIRTIO_RING_F_EVENT_IDX;
| 1 << VIRTIO_RING_F_EVENT_IDX
| 1 << VIRTIO_NET_F_GUEST_TSO6
| 1 << VIRTIO_NET_F_HOST_TSO6
| 1 << VIRTIO_NET_F_GUEST_ECN
| 1 << VIRTIO_NET_F_HOST_ECN;

let mut config_space = ConfigSpace::default();
if let Some(mac) = guest_mac {
Expand Down Expand Up @@ -210,10 +216,6 @@ impl Net {
) -> Result<Self, NetError> {
let tap = Tap::open_named(tap_if_name).map_err(NetError::TapOpen)?;

// Set offload flags to match the virtio features below.
tap.set_offload(gen::TUN_F_CSUM | gen::TUN_F_UFO | gen::TUN_F_TSO4 | gen::TUN_F_TSO6)
.map_err(NetError::TapSetOffload)?;

let vnet_hdr_size = i32::try_from(vnet_hdr_len()).unwrap();
tap.set_vnet_hdr_size(vnet_hdr_size)
.map_err(NetError::TapSetVnetHdrSize)?;
Expand Down Expand Up @@ -644,6 +646,44 @@ impl Net {
}
}

fn build_tap_supported_features(virtio_supported_features: u64) -> u32 {
let add_if_supported =
|tap_features: &mut u32, virtio_features: u64, tap_flag: u32, virtio_flag: u32| {
if virtio_features & (1 << virtio_flag) != 0 {
*tap_features |= tap_flag;
}
};

let mut tap_features: u32 = 0;

add_if_supported(
&mut tap_features,
virtio_supported_features,
gen::TUN_F_CSUM,
VIRTIO_NET_F_CSUM,
);
add_if_supported(
&mut tap_features,
virtio_supported_features,
gen::TUN_F_UFO,
VIRTIO_NET_F_GUEST_UFO,
);
add_if_supported(
&mut tap_features,
virtio_supported_features,
gen::TUN_F_TSO4,
VIRTIO_NET_F_GUEST_TSO4,
);
add_if_supported(
&mut tap_features,
virtio_supported_features,
gen::TUN_F_TSO6,
VIRTIO_NET_F_GUEST_TSO6,
);

tap_features
}

/// Updates the parameters for the rate limiters
pub fn patch_rate_limiters(
&mut self,
Expand Down Expand Up @@ -859,6 +899,11 @@ impl VirtioDevice for Net {
}
}

let supported_flags: u32 = Net::build_tap_supported_features(self.acked_features);
self.tap
.set_offload(supported_flags)
.map_err(super::super::ActivateError::TapSetOffload)?;

if self.activate_evt.write(1).is_err() {
error!("Net: Cannot write to activate_evt");
return Err(super::super::ActivateError::BadActivate);
Expand Down Expand Up @@ -978,7 +1023,11 @@ pub mod tests {
| 1 << VIRTIO_NET_F_HOST_TSO4
| 1 << VIRTIO_NET_F_HOST_UFO
| 1 << VIRTIO_F_VERSION_1
| 1 << VIRTIO_RING_F_EVENT_IDX;
| 1 << VIRTIO_RING_F_EVENT_IDX
| 1 << VIRTIO_NET_F_GUEST_TSO6
| 1 << VIRTIO_NET_F_HOST_TSO6
| 1 << VIRTIO_NET_F_GUEST_ECN
| 1 << VIRTIO_NET_F_HOST_ECN;

assert_eq!(
net.avail_features_by_page(0),
Expand All @@ -996,6 +1045,37 @@ pub mod tests {
assert_eq!(net.acked_features, features);
}

#[test]
// We can't get offload features, that were set up to a TAP device by ioctl,
// hence that we have to validate, that we sort out unsupported features correctly
fn test_build_tap_supported_features_all() {
let supported_features = 1 << VIRTIO_NET_F_CSUM
| 1 << VIRTIO_NET_F_GUEST_UFO
| 1 << VIRTIO_NET_F_GUEST_TSO4
| 1 << VIRTIO_NET_F_GUEST_TSO6;

let expected_tap_features =
gen::TUN_F_CSUM | gen::TUN_F_UFO | gen::TUN_F_TSO4 | gen::TUN_F_TSO6;

let supported_flags = Net::build_tap_supported_features(supported_features);

assert_eq!(supported_flags, expected_tap_features);
}

#[test]
fn test_build_tap_supported_features_one_by_one() {
let features = [
(1 << VIRTIO_NET_F_CSUM, gen::TUN_F_CSUM),
(1 << VIRTIO_NET_F_GUEST_UFO, gen::TUN_F_UFO),
(1 << VIRTIO_NET_F_GUEST_TSO4, gen::TUN_F_TSO4),
(1 << VIRTIO_NET_F_GUEST_TSO6, gen::TUN_F_TSO6),
];
for (virtio_flag, tap_flag) in features {
let supported_flags = Net::build_tap_supported_features(virtio_flag);
assert_eq!(supported_flags, tap_flag);
}
}

#[test]
fn test_virtio_device_read_config() {
let mut net = default_net();
Expand Down
2 changes: 0 additions & 2 deletions src/vmm/src/devices/virtio/net/mod.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -45,8 +45,6 @@ pub enum NetQueue {
pub enum NetError {
/// Open tap device failed: {0}
TapOpen(TapError),
/// Setting tap interface offload flags failed: {0}
TapSetOffload(TapError),
/// Setting vnet header size failed: {0}
TapSetVnetHdrSize(TapError),
/// EventFd error: {0}
Expand Down