dragonball: Minor changes for Chao's comments

- Remove two panic statements from InsertNetworkDevice test.
- Rename `NUM_QUEUES` to `DEFAULT_NUM_QUEUES`, `QUEUE_SIZE` to
  `DEFAULT_QUEUE_SIZE` for vhost-net and virtio-net.

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

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

@@ -19,9 +19,11 @@ use crate::device_manager::virtio_net_dev_mgr;
 /// An enum to specify a backend of Virtio network
 pub enum Backend {
     #[serde(rename = "virtio")]
+    #[cfg(feature = "virtio-net")]
     /// Virtio-net
     Virtio(VirtioConfig),
     #[serde(rename = "vhost")]
+    #[cfg(feature = "vhost-net")]
     /// Vhost-net
     Vhost(VirtioConfig),
 }
@@ -79,7 +81,9 @@ impl From<NetworkInterfaceConfig> for VirtioNetDeviceConfigInfo {
 #[cfg(feature = "virtio-net")]
 impl From<&NetworkInterfaceConfig> for VirtioNetDeviceConfigInfo {
     fn from(value: &NetworkInterfaceConfig) -> Self {
-        let queue_size = value.queue_size.unwrap_or(virtio_net_dev_mgr::QUEUE_SIZE);
+        let queue_size = value
+            .queue_size
+            .unwrap_or(virtio_net_dev_mgr::DEFAULT_QUEUE_SIZE);
 
         // It is safe because we tested the type of config before.
         let config = match &value.backend {
@@ -90,7 +94,7 @@ impl From<&NetworkInterfaceConfig> for VirtioNetDeviceConfigInfo {
         Self {
             iface_id: config.iface_id.clone(),
             host_dev_name: config.host_dev_name.clone(),
-            num_queues: virtio_net_dev_mgr::NUM_QUEUES,
+            num_queues: virtio_net_dev_mgr::DEFAULT_NUM_QUEUES,
             queue_size,
             guest_mac: value.guest_mac,
             rx_rate_limiter: config.rx_rate_limiter.clone(),
@@ -113,8 +117,12 @@ impl From<NetworkInterfaceConfig> for VhostNetDeviceConfigInfo {
 #[cfg(feature = "vhost-net")]
 impl From<&NetworkInterfaceConfig> for VhostNetDeviceConfigInfo {
     fn from(value: &NetworkInterfaceConfig) -> Self {
-        let num_queues = value.num_queues.unwrap_or(vhost_net_dev_mgr::NUM_QUEUES);
+        let num_queues = value
-        let queue_size = value.queue_size.unwrap_or(vhost_net_dev_mgr::QUEUE_SIZE);
+            .num_queues
+            .unwrap_or(vhost_net_dev_mgr::DEFAULT_NUM_QUEUES);
+        let queue_size = value
+            .queue_size
+            .unwrap_or(vhost_net_dev_mgr::DEFAULT_QUEUE_SIZE);
 
         // It is safe because we tested the type of config before.
         let config = match &value.backend {

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

@@ -191,7 +191,6 @@ pub enum VmmAction {
     /// are the RX and TX rate limiters.
     UpdateBlockDevice(BlockDeviceConfigUpdateInfo),
 
-    #[cfg(any(feature = "virtio-net", feature = "vhost-net"))]
     /// Add a new network interface config or update one that already exists using the
     /// `NetworkInterfaceConfig` as input. This action can only be called before the microVM has
     /// booted. The response is sent using the `OutcomeSender`.
@@ -318,20 +317,11 @@ 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 {
-                Backend::Virtio(_) => {
-                    #[cfg(not(feature = "virtio-net"))]
-                    panic!("virtio-net feature is not enabled");
                 #[cfg(feature = "virtio-net")]
-                    self.add_virtio_net_device(vmm, event_mgr, config.into())
+                Backend::Virtio(_) => self.add_virtio_net_device(vmm, event_mgr, config.into()),
-                }
-                Backend::Vhost(_) => {
-                    #[cfg(not(feature = "vhost-net"))]
-                    panic!("vhost-net feature is not enabled");
                 #[cfg(feature = "vhost-net")]
-                    self.add_vhost_net_device(vmm, event_mgr, config.into())
+                Backend::Vhost(_) => self.add_vhost_net_device(vmm, event_mgr, config.into()),
-                }
             },
             #[cfg(feature = "virtio-net")]
             VmmAction::UpdateNetworkInterface(netif_update) => {

src/dragonball/src/device_manager/vhost_net_dev_mgr.rs

@@ -17,9 +17,9 @@ use crate::address_space_manager::{GuestAddressSpaceImpl, GuestRegionImpl};
 use crate::config_manager::{ConfigItem, DeviceConfigInfos};
 
 /// Default number of virtio queues, one rx/tx pair.
-pub const NUM_QUEUES: usize = 2;
+pub const DEFAULT_NUM_QUEUES: usize = 2;
 /// Default size of virtio queues.
-pub const QUEUE_SIZE: u16 = 256;
+pub const DEFAULT_QUEUE_SIZE: u16 = 256;
 // The flag of whether to use the shared irq.
 const USE_SHARED_IRQ: bool = true;
 // The flag of whether to use the generic irq.
@@ -96,12 +96,12 @@ impl VhostNetDeviceConfigInfo {
         let queue_size = if self.queue_size > 0 {
             self.queue_size
         } else {
-            QUEUE_SIZE
+            DEFAULT_QUEUE_SIZE
         };
         let num_queues = if self.num_queues > 0 {
             self.num_queues
         } else {
-            NUM_QUEUES
+            DEFAULT_NUM_QUEUES
         };
 
         (0..num_queues).map(|_| queue_size).collect()

src/dragonball/src/device_manager/virtio_net_dev_mgr.rs

@@ -26,9 +26,9 @@ use crate::get_bucket_update;
 use super::DbsMmioV2Device;
 
 /// Default number of virtio queues, one rx/tx pair.
-pub const NUM_QUEUES: usize = 2;
+pub const DEFAULT_NUM_QUEUES: usize = 2;
 /// Default size of virtio queues.
-pub const QUEUE_SIZE: u16 = 256;
+pub const DEFAULT_QUEUE_SIZE: u16 = 256;
 // The flag of whether to use the shared irq.
 const USE_SHARED_IRQ: bool = true;
 // The flag of whether to use the generic irq.
@@ -164,12 +164,12 @@ impl VirtioNetDeviceConfigInfo {
     pub fn queue_sizes(&self) -> Vec<u16> {
         let mut queue_size = self.queue_size;
         if queue_size == 0 {
-            queue_size = QUEUE_SIZE;
+            queue_size = DEFAULT_QUEUE_SIZE;
         }
         let num_queues = if self.num_queues > 0 {
             self.num_queues
         } else {
-            NUM_QUEUES
+            DEFAULT_NUM_QUEUES
         };
 
         (0..num_queues).map(|_| queue_size).collect::<Vec<u16>>()