dragonball: Remove vhost-net dependency on virtio-net

This patch is to remove vhost-net dependency on virtio-net for
dbs-virtio-devices crate. Then, the feature of vhost-net is able to enable
without enabling virtio-net device, error, etc.

Fixes: #8423

Signed-off-by: Xuewei Niu <niuxuewei.nxw@antgroup.com>

src/dragonball/src/api/v1/virtio_net.rs

@@ -3,6 +3,8 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 
+use core::panic;
+
 use dbs_utils::net::MacAddr;
 use serde::{Deserialize, Serialize};
 
@@ -29,8 +31,14 @@ pub enum Backend {
 }
 
 impl Default for Backend {
+    #[allow(unreachable_code)]
     fn default() -> Self {
-        Self::Virtio(VirtioConfig::default())
+        #[cfg(feature = "virtio-net")]
+        return Self::Virtio(VirtioConfig::default());
+        #[cfg(feature = "vhost-net")]
+        return Self::Vhost(VirtioConfig::default());
+
+        panic!("no available default network backend")
     }
 }
 
@@ -86,6 +94,7 @@ impl From<&NetworkInterfaceConfig> for VirtioNetDeviceConfigInfo {
             .unwrap_or(virtio_net_dev_mgr::DEFAULT_QUEUE_SIZE);
 
         // It is safe because we tested the type of config before.
+        #[allow(unreachable_patterns)]
         let config = match &value.backend {
             Backend::Virtio(config) => config,
             _ => panic!("The virtio backend config is invalid: {:?}", value),
@@ -125,6 +134,7 @@ impl From<&NetworkInterfaceConfig> for VhostNetDeviceConfigInfo {
             .unwrap_or(vhost_net_dev_mgr::DEFAULT_QUEUE_SIZE);
 
         // It is safe because we tested the type of config before.
+        #[allow(unreachable_patterns)]
         let config = match &value.backend {
             Backend::Vhost(config) => config,
             _ => panic!("The virtio backend config is invalid: {:?}", value),

src/dragonball/src/api/v1/vmm_action.rs

@@ -200,6 +200,8 @@ pub enum VmmAction {
     #[cfg(feature = "virtio-net")]
     /// Update a network interface, after microVM start. Currently, the only updatable properties
     /// are the RX and TX rate limiters.
+    /// TODO: vhost-net rate limiters aren't implemented, see:
+    /// https://github.com/kata-containers/kata-containers/issues/8327
     UpdateNetworkInterface(VirtioNetDeviceConfigUpdateInfo),
 
     #[cfg(feature = "virtio-fs")]
@@ -318,6 +320,7 @@ impl VmmService {
             VmmAction::RemoveBlockDevice(drive_id) => {
                 self.remove_block_device(vmm, event_mgr, &drive_id)
             }
+            #[cfg(any(feature = "virtio-net", feature = "vhost-net"))]
             VmmAction::InsertNetworkDevice(config) => match config.backend {
                 #[cfg(feature = "virtio-net")]
                 Backend::Virtio(_) => self.add_virtio_net_device(vmm, event_mgr, config.into()),

src/dragonball/src/dbs_virtio_devices/Cargo.toml

@@ -52,4 +52,4 @@ virtio-fs-pro = ["virtio-fs", "nydus-storage/backend-registry", "nydus-storage/b
 virtio-mem = ["virtio-mmio"]
 virtio-balloon = ["virtio-mmio"]
 vhost = ["virtio-mmio", "vhost-rs/vhost-user-master", "vhost-rs/vhost-kern"]
-vhost-net = ["virtio-net", "vhost", "vhost-rs/vhost-net"]
+vhost-net = ["vhost", "vhost-rs/vhost-net"]

src/dragonball/src/dbs_virtio_devices/src/lib.rs

@@ -46,7 +46,10 @@ pub mod vhost;
 
 use std::io::Error as IOError;
 
-use net::NetError;
+#[cfg(any(feature = "virtio-net", feature = "vhost-net"))]
+use dbs_utils::metric::SharedIncMetric;
+#[cfg(any(feature = "virtio-net", feature = "vhost-net"))]
+use serde::Serialize;
 use virtio_queue::Error as VqError;
 use vm_memory::{GuestAddress, GuestAddressSpace, GuestMemoryError};
 
@@ -212,7 +215,7 @@ pub enum Error {
 
     #[cfg(feature = "virtio-net")]
     #[error("virtio-net error: {0:?}")]
-    VirtioNet(NetError),
+    VirtioNet(net::NetError),
 
     #[cfg(feature = "vhost-net")]
     #[error("vhost-net error: {0:?}")]
@@ -229,7 +232,7 @@ pub enum Error {
 }
 
 // Error for tap devices
-#[cfg(feature = "virtio-net")]
+#[cfg(any(feature = "virtio-net", feature = "vhost-net"))]
 #[derive(Debug, thiserror::Error)]
 pub enum TapError {
     #[error("missing {0} flags")]
@@ -248,6 +251,48 @@ pub enum TapError {
     Enable(#[source] dbs_utils::net::TapError),
 }
 
+#[cfg(any(feature = "virtio-net", feature = "vhost-net"))]
+#[inline]
+pub fn vnet_hdr_len() -> usize {
+    std::mem::size_of::<virtio_bindings::bindings::virtio_net::virtio_net_hdr_v1>()
+}
+
+/// Metrics specific to the net device.
+#[cfg(any(feature = "virtio-net", feature = "vhost-net"))]
+#[derive(Default, Serialize)]
+pub struct NetDeviceMetrics {
+    /// Number of times when handling events on a network device.
+    pub event_count: SharedIncMetric,
+    /// Number of times when activate failed on a network device.
+    pub activate_fails: SharedIncMetric,
+    /// Number of times when interacting with the space config of a network device failed.
+    pub cfg_fails: SharedIncMetric,
+    /// Number of times when handling events on a network device failed.
+    pub event_fails: SharedIncMetric,
+    /// Number of events associated with the receiving queue.
+    pub rx_queue_event_count: SharedIncMetric,
+    /// Number of events associated with the rate limiter installed on the receiving path.
+    pub rx_event_rate_limiter_count: SharedIncMetric,
+    /// Number of events received on the associated tap.
+    pub rx_tap_event_count: SharedIncMetric,
+    /// Number of bytes received.
+    pub rx_bytes_count: SharedIncMetric,
+    /// Number of packets received.
+    pub rx_packets_count: SharedIncMetric,
+    /// Number of errors while receiving data.
+    pub rx_fails: SharedIncMetric,
+    /// Number of transmitted bytes.
+    pub tx_bytes_count: SharedIncMetric,
+    /// Number of errors while transmitting data.
+    pub tx_fails: SharedIncMetric,
+    /// Number of transmitted packets.
+    pub tx_packets_count: SharedIncMetric,
+    /// Number of events associated with the transmitting queue.
+    pub tx_queue_event_count: SharedIncMetric,
+    /// Number of events associated with the rate limiter installed on the transmitting path.
+    pub tx_rate_limiter_event_count: SharedIncMetric,
+}
+
 /// Specialized std::result::Result for Virtio device operations.
 pub type Result<T> = std::result::Result<T, Error>;
 

src/dragonball/src/dbs_virtio_devices/src/net.rs

@@ -9,7 +9,6 @@ use std::any::Any;
 use std::cmp;
 use std::io::{self, Read, Write};
 use std::marker::PhantomData;
-use std::mem;
 use std::ops::Deref;
 use std::os::unix::io::AsRawFd;
 use std::sync::{mpsc, Arc};
@@ -18,12 +17,11 @@ use dbs_device::resources::ResourceConstraint;
 use dbs_utils::epoll_manager::{
     EpollManager, EventOps, EventSet, Events, MutEventSubscriber, SubscriberId,
 };
-use dbs_utils::metric::{IncMetric, SharedIncMetric};
+use dbs_utils::metric::IncMetric;
 use dbs_utils::net::{net_gen, MacAddr, Tap, MAC_ADDR_LEN};
 use dbs_utils::rate_limiter::{BucketUpdate, RateLimiter, TokenType};
 use libc;
 use log::{debug, error, info, trace, warn};
-use serde::Serialize;
 use virtio_bindings::bindings::virtio_net::*;
 use virtio_queue::{QueueOwnedT, QueueSync, QueueT};
 use vm_memory::{Bytes, GuestAddress, GuestAddressSpace, GuestMemoryRegion, GuestRegionMmap};
@@ -31,8 +29,8 @@ use vmm_sys_util::eventfd::EventFd;
 
 use crate::device::{VirtioDeviceConfig, VirtioDeviceInfo};
 use crate::{
-    ActivateError, ActivateResult, ConfigResult, DbsGuestAddressSpace, Error, Result, TapError,
-    VirtioDevice, VirtioQueueConfig, TYPE_NET,
+    vnet_hdr_len, ActivateError, ActivateResult, ConfigResult, DbsGuestAddressSpace, Error,
+    NetDeviceMetrics, Result, TapError, VirtioDevice, VirtioQueueConfig, TYPE_NET,
 };
 
 const NET_DRIVER_NAME: &str = "virtio-net";
@@ -64,41 +62,6 @@ pub enum NetError {
     TapError(#[source] TapError),
 }
 
-/// Metrics specific to the net device.
-#[derive(Default, Serialize)]
-pub struct NetDeviceMetrics {
-    /// Number of times when handling events on a network device.
-    pub event_count: SharedIncMetric,
-    /// Number of times when activate failed on a network device.
-    pub activate_fails: SharedIncMetric,
-    /// Number of times when interacting with the space config of a network device failed.
-    pub cfg_fails: SharedIncMetric,
-    /// Number of times when handling events on a network device failed.
-    pub event_fails: SharedIncMetric,
-    /// Number of events associated with the receiving queue.
-    pub rx_queue_event_count: SharedIncMetric,
-    /// Number of events associated with the rate limiter installed on the receiving path.
-    pub rx_event_rate_limiter_count: SharedIncMetric,
-    /// Number of events received on the associated tap.
-    pub rx_tap_event_count: SharedIncMetric,
-    /// Number of bytes received.
-    pub rx_bytes_count: SharedIncMetric,
-    /// Number of packets received.
-    pub rx_packets_count: SharedIncMetric,
-    /// Number of errors while receiving data.
-    pub rx_fails: SharedIncMetric,
-    /// Number of transmitted bytes.
-    pub tx_bytes_count: SharedIncMetric,
-    /// Number of errors while transmitting data.
-    pub tx_fails: SharedIncMetric,
-    /// Number of transmitted packets.
-    pub tx_packets_count: SharedIncMetric,
-    /// Number of events associated with the transmitting queue.
-    pub tx_queue_event_count: SharedIncMetric,
-    /// Number of events associated with the rate limiter installed on the transmitting path.
-    pub tx_rate_limiter_event_count: SharedIncMetric,
-}
-
 struct TxVirtio<Q: QueueT> {
     queue: VirtioQueueConfig<Q>,
     rate_limiter: RateLimiter,
@@ -143,10 +106,6 @@ impl<Q: QueueT> RxVirtio<Q> {
     }
 }
 
-pub fn vnet_hdr_len() -> usize {
-    mem::size_of::<virtio_net_hdr_v1>()
-}
-
 #[allow(dead_code)]
 pub(crate) struct NetEpollHandler<
     AS: GuestAddressSpace,

src/dragonball/src/dbs_virtio_devices/src/vhost/vhost_kern/net.rs

@@ -31,14 +31,14 @@ use virtio_bindings::bindings::virtio_ring::*;
 use virtio_queue::{Descriptor, DescriptorChain, QueueT};
 use vm_memory::{Address, Bytes, GuestMemory, GuestMemoryRegion, MemoryRegionAddress};
 
-use crate::net::{vnet_hdr_len, NetDeviceMetrics};
 #[cfg(test)]
 use crate::vhost::vhost_kern::test_utils::{
     MockVhostBackend as VhostBackend, MockVhostNet as VhostNet,
 };
 use crate::{
-    ActivateError, ConfigResult, DbsGuestAddressSpace, Error as VirtioError,
-    Result as VirtioResult, TapError, VirtioDevice, VirtioDeviceConfig, VirtioDeviceInfo, TYPE_NET,
+    vnet_hdr_len, ActivateError, ConfigResult, DbsGuestAddressSpace, Error as VirtioError,
+    NetDeviceMetrics, Result as VirtioResult, TapError, VirtioDevice, VirtioDeviceConfig,
+    VirtioDeviceInfo, TYPE_NET,
 };
 
 const NET_DRIVER_NAME: &str = "vhost-net";