vm-virtio: Simplify virtio-net configuration

This commit introduces a clear definition of the virtio-net
configuration structure, allowing both vhost-user-net and
virtio-net devices to rely on it.

This makes the code more readable for developers.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This commit is contained in:
Sebastien Boeuf 2020-01-27 17:37:14 +01:00 committed by Rob Bradford
parent 9efaff73fa
commit 8946a09afd
3 changed files with 54 additions and 42 deletions

View File

@ -7,8 +7,8 @@
use super::net_util::{
build_net_config_space, build_net_config_space_with_mq, open_tap, register_listener,
unregister_listener, CtrlVirtio, NetCtrlEpollHandler, RxVirtio, TxVirtio, KILL_EVENT,
NET_EVENTS_COUNT, PAUSE_EVENT, RX_QUEUE_EVENT, RX_TAP_EVENT, TX_QUEUE_EVENT,
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::{
@ -32,7 +32,7 @@ use std::thread;
use std::vec::Vec;
use virtio_bindings::bindings::virtio_net::*;
use vm_device::{Migratable, MigratableError, Pausable, Snapshotable};
use vm_memory::GuestMemoryMmap;
use vm_memory::{ByteValued, GuestMemoryMmap};
use vmm_sys_util::eventfd::EventFd;
#[derive(Debug)]
@ -297,9 +297,7 @@ pub struct Net {
taps: Option<Vec<Tap>>,
avail_features: u64,
acked_features: u64,
// The config space will only consist of the MAC address specified by the user,
// or nothing, if no such address if provided.
config_space: Vec<u8>,
config: VirtioNetConfig,
queue_evts: Option<Vec<EventFd>>,
interrupt_cb: Option<Arc<dyn VirtioInterrupt>>,
epoll_threads: Option<Vec<thread::JoinHandle<result::Result<(), DeviceError>>>>,
@ -332,12 +330,11 @@ impl Net {
avail_features |= 1 << VIRTIO_NET_F_CTRL_VQ;
let queue_num = num_queues + 1;
let mut config_space;
let mut config = VirtioNetConfig::default();
if let Some(mac) = guest_mac {
config_space = build_net_config_space(mac, num_queues, &mut avail_features);
build_net_config_space(&mut config, mac, num_queues, &mut avail_features);
} else {
config_space = Vec::new();
build_net_config_space_with_mq(num_queues, &mut config_space, &mut avail_features);
build_net_config_space_with_mq(&mut config, num_queues, &mut avail_features);
}
Ok(Net {
@ -346,7 +343,7 @@ impl Net {
taps: Some(taps),
avail_features,
acked_features: 0u64,
config_space,
config,
queue_evts: None,
interrupt_cb: None,
epoll_threads: None,
@ -425,26 +422,28 @@ impl VirtioDevice for Net {
}
fn read_config(&self, offset: u64, mut data: &mut [u8]) {
let config_len = self.config_space.len() as u64;
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(&self.config_space[offset as usize..cmp::min(end, config_len) as usize])
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 = self.config_space.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) = self.config_space.split_at_mut(offset as usize);
let (_, right) = config_slice.split_at_mut(offset as usize);
right.copy_from_slice(&data[..]);
}

View File

@ -5,7 +5,7 @@
use super::Error as DeviceError;
use super::{DescriptorChain, DeviceEventT, Queue};
use arc_swap::ArcSwap;
use net_util::{MacAddr, Tap, TapError, MAC_ADDR_LEN};
use net_util::{MacAddr, Tap, TapError};
use std::cmp;
use std::io::{self, Write};
use std::mem;
@ -25,11 +25,6 @@ type Result<T> = std::result::Result<T, Error>;
const MAX_BUFFER_SIZE: usize = 65562;
const QUEUE_SIZE: usize = 256;
const CONFIG_SPACE_MAC: usize = MAC_ADDR_LEN;
const CONFIG_SPACE_STATUS: usize = 2;
const CONFIG_SPACE_QUEUE_PAIRS: usize = 2;
const CONFIG_SPACE_NET: usize = CONFIG_SPACE_MAC + CONFIG_SPACE_STATUS + CONFIG_SPACE_QUEUE_PAIRS;
// The guest has made a buffer available to receive a frame into.
pub const RX_QUEUE_EVENT: DeviceEventT = 0;
// The transmit queue has a frame that is ready to send from the guest.
@ -47,6 +42,20 @@ const CTRL_QUEUE_EVENT: DeviceEventT = 0;
// Number of DeviceEventT events supported by this implementation.
const CTRL_EVENT_COUNT: usize = 3;
#[repr(C, packed)]
#[derive(Copy, Clone, Debug, Default)]
pub struct VirtioNetConfig {
pub mac: [u8; 6],
pub status: u16,
pub max_virtqueue_pairs: u16,
pub mtu: u16,
pub speed: u32,
pub duplex: u8,
}
// Safe because it only has data and has no implicit padding.
unsafe impl ByteValued for VirtioNetConfig {}
#[derive(Debug)]
pub enum Error {
/// Read process MQ.
@ -414,33 +423,27 @@ impl RxVirtio {
}
pub fn build_net_config_space(
mut config: &mut VirtioNetConfig,
mac: MacAddr,
num_queues: usize,
mut avail_features: &mut u64,
) -> Vec<u8> {
let mut config_space = Vec::with_capacity(MAC_ADDR_LEN);
unsafe { config_space.set_len(MAC_ADDR_LEN) }
config_space[..].copy_from_slice(mac.get_bytes());
) {
config.mac.copy_from_slice(mac.get_bytes());
*avail_features |= 1 << VIRTIO_NET_F_MAC;
build_net_config_space_with_mq(num_queues, &mut config_space, &mut avail_features);
config_space
build_net_config_space_with_mq(&mut config, num_queues, &mut avail_features);
}
pub fn build_net_config_space_with_mq(
config: &mut VirtioNetConfig,
num_queues: usize,
config_space: &mut Vec<u8>,
avail_features: &mut u64,
) {
let num_queue_pairs = (num_queues / 2) as u16;
if (num_queue_pairs >= VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN as u16)
&& (num_queue_pairs <= VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX as u16)
{
config_space.resize(CONFIG_SPACE_NET, 0);
let max_queue_pairs = num_queue_pairs.to_le_bytes();
config_space[CONFIG_SPACE_MAC + CONFIG_SPACE_STATUS..CONFIG_SPACE_NET]
.copy_from_slice(&max_queue_pairs);
config.max_virtqueue_pairs = num_queue_pairs;
*avail_features |= 1 << VIRTIO_NET_F_MQ;
}
}

View File

@ -1,7 +1,9 @@
// Copyright 2019 Intel Corporation. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
use super::super::net_util::{build_net_config_space, CtrlVirtio, NetCtrlEpollHandler};
use super::super::net_util::{
build_net_config_space, CtrlVirtio, NetCtrlEpollHandler, VirtioNetConfig,
};
use super::super::Error as CtrlError;
use super::super::{ActivateError, ActivateResult, Queue, VirtioDevice, VirtioDeviceType};
use super::handler::*;
@ -26,7 +28,7 @@ use vhost_rs::VhostBackend;
use virtio_bindings::bindings::virtio_net;
use virtio_bindings::bindings::virtio_ring;
use vm_device::{Migratable, MigratableError, Pausable, Snapshotable};
use vm_memory::GuestMemoryMmap;
use vm_memory::{ByteValued, GuestMemoryMmap};
use vmm_sys_util::eventfd::EventFd;
const DEFAULT_QUEUE_NUMBER: usize = 2;
@ -41,7 +43,7 @@ pub struct Net {
avail_features: u64,
acked_features: u64,
backend_features: u64,
config_space: Vec<u8>,
config: VirtioNetConfig,
queue_sizes: Vec<u16>,
queue_evts: Option<Vec<EventFd>>,
interrupt_cb: Option<Arc<dyn VirtioInterrupt>>,
@ -122,7 +124,13 @@ impl Net {
avail_features |= 1 << virtio_net::VIRTIO_NET_F_CTRL_VQ;
let queue_num = vu_cfg.num_queues + 1;
let config_space = build_net_config_space(mac_addr, vu_cfg.num_queues, &mut avail_features);
let mut config = VirtioNetConfig::default();
build_net_config_space(
&mut config,
mac_addr,
vu_cfg.num_queues,
&mut avail_features,
);
// Send set_vring_base here, since it could tell backends, like OVS + DPDK,
// how many virt queues to be handled, which backend required to know at early stage.
@ -139,7 +147,7 @@ impl Net {
avail_features,
acked_features,
backend_features,
config_space,
config,
queue_sizes: vec![vu_cfg.queue_size; queue_num],
queue_evts: None,
interrupt_cb: None,
@ -201,26 +209,28 @@ impl VirtioDevice for Net {
}
fn read_config(&self, offset: u64, mut data: &mut [u8]) {
let config_len = self.config_space.len() as u64;
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(&self.config_space[offset as usize..cmp::min(end, config_len) as usize])
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 = self.config_space.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) = self.config_space.split_at_mut(offset as usize);
let (_, right) = config_slice.split_at_mut(offset as usize);
right.copy_from_slice(&data[..]);
}