virtio-devices: vhost_user: Use VhostUserCommon::spawn_worker

Replace manual thread management with the use of
VhostUserCommon::spawn_worker() which is just a thin layer over
VirtioCommon::spawn_worker() but handling VhostUserCommon reset. This
removes some manual thread management and also triggers a reset upon
spawn failure.

Assisted-by: Claude:Opus-4.7
Signed-off-by: Rob Bradford <rbradford@meta.com>

virtio-devices/src/vhost_user/blk.rs

@@ -26,7 +26,6 @@ use super::super::{ActivateResult, VirtioCommon, VirtioDevice, VirtioDeviceType}
 use super::vu_common_ctrl::{VhostUserConfig, VhostUserHandle};
 use super::{DEFAULT_VIRTIO_FEATURES, Error, Result};
 use crate::seccomp_filters::Thread;
-use crate::thread_helper::spawn_virtio_thread;
 use crate::vhost_user::{VhostUserCommon, VhostUserState};
 use crate::{GuestMemoryMmap, GuestRegionMmap, VIRTIO_F_ACCESS_PLATFORM};
 
@@ -297,19 +296,15 @@ impl VirtioDevice for Blk {
         let paused = self.vu_common.virtio_common.paused.clone();
         let paused_sync = self.vu_common.virtio_common.paused_sync.clone();
 
-        let mut epoll_threads = Vec::new();
-
-        spawn_virtio_thread(
+        self.vu_common.spawn_worker(
             &self.id,
             &self.seccomp_action,
             Thread::VirtioVhostBlock,
-            &mut epoll_threads,
             &self.exit_evt,
             device_status.clone(),
             interrupt_cb.clone(),
             move || handler.run(&paused, paused_sync.as_ref().unwrap()),
         )?;
-        self.vu_common.virtio_common.epoll_threads = Some(epoll_threads);
 
         Ok(())
     }

virtio-devices/src/vhost_user/fs.rs

@@ -21,7 +21,6 @@ use vmm_sys_util::eventfd::EventFd;
 use super::vu_common_ctrl::VhostUserHandle;
 use super::{DEFAULT_VIRTIO_FEATURES, Error, Result};
 use crate::seccomp_filters::Thread;
-use crate::thread_helper::spawn_virtio_thread;
 use crate::vhost_user::{VhostUserCommon, VhostUserState};
 use crate::{
     ActivateResult, GuestMemoryMmap, GuestRegionMmap, MmapRegion, VIRTIO_F_ACCESS_PLATFORM,
@@ -271,18 +270,15 @@ impl VirtioDevice for Fs {
         let paused = self.vu_common.virtio_common.paused.clone();
         let paused_sync = self.vu_common.virtio_common.paused_sync.clone();
 
-        let mut epoll_threads = Vec::new();
-        spawn_virtio_thread(
+        self.vu_common.spawn_worker(
             &self.id,
             &self.seccomp_action,
             Thread::VirtioVhostFs,
-            &mut epoll_threads,
             &self.exit_evt,
             device_status.clone(),
             interrupt_cb.clone(),
             move || handler.run(&paused, paused_sync.as_ref().unwrap()),
         )?;
-        self.vu_common.virtio_common.epoll_threads = Some(epoll_threads);
 
         event!("virtio-device", "activated", "id", &self.id);
         Ok(())

virtio-devices/src/vhost_user/generic_vhost_user.rs

@@ -22,7 +22,6 @@ use vmm_sys_util::eventfd::EventFd;
 use super::vu_common_ctrl::VhostUserHandle;
 use super::{Error, Result};
 use crate::seccomp_filters::Thread;
-use crate::thread_helper::spawn_virtio_thread;
 use crate::vhost_user::{VhostUserCommon, VhostUserState};
 use crate::{
     ActivateResult, GuestMemoryMmap, GuestRegionMmap, MmapRegion, VIRTIO_F_ACCESS_PLATFORM,
@@ -333,18 +332,15 @@ impl VirtioDevice for GenericVhostUser {
         let paused = self.vu_common.virtio_common.paused.clone();
         let paused_sync = self.vu_common.virtio_common.paused_sync.clone();
 
-        let mut epoll_threads = Vec::new();
-        spawn_virtio_thread(
+        self.vu_common.spawn_worker(
             &self.id,
             &self.seccomp_action,
             Thread::VirtioGenericVhostUser,
-            &mut epoll_threads,
             &self.exit_evt,
             device_status.clone(),
             interrupt_cb.clone(),
             move || handler.run(&paused, paused_sync.as_ref().unwrap()),
         )?;
-        self.vu_common.virtio_common.epoll_threads = Some(epoll_threads);
 
         event!("virtio-device", "activated", "id", &self.id);
         Ok(())

virtio-devices/src/vhost_user/net.rs

@@ -24,7 +24,6 @@ use vm_migration::{Migratable, MigratableError, Pausable, Snapshot, Snapshottabl
 use vmm_sys_util::eventfd::EventFd;
 
 use crate::seccomp_filters::Thread;
-use crate::thread_helper::spawn_virtio_thread;
 use crate::vhost_user::vu_common_ctrl::{VhostUserConfig, VhostUserHandle};
 use crate::vhost_user::{DEFAULT_VIRTIO_FEATURES, Error, Result, VhostUserCommon, VhostUserState};
 use crate::{
@@ -311,18 +310,15 @@ impl VirtioDevice for Net {
             self.vu_common.virtio_common.paused_sync = Some(Arc::new(Barrier::new(3)));
             let paused_sync = self.vu_common.virtio_common.paused_sync.clone();
 
-            let mut ctrl_threads = Vec::new();
-            spawn_virtio_thread(
+            self.vu_common.virtio_common.spawn_worker(
                 &format!("{}_ctrl", self.id),
                 &self.seccomp_action,
                 Thread::VirtioVhostNetCtl,
-                &mut ctrl_threads,
                 &self.exit_evt,
                 device_status.clone(),
                 interrupt_cb.clone(),
                 move || ctrl_handler.run_ctrl(&paused, paused_sync.as_ref().unwrap()),
             )?;
-            self.vu_common.virtio_common.epoll_threads = Some(ctrl_threads);
         }
 
         let backend_req_handler: Option<FrontendReqHandler<BackendReqHandler>> = None;
@@ -349,16 +345,10 @@ impl VirtioDevice for Net {
         let paused = self.vu_common.virtio_common.paused.clone();
         let paused_sync = self.vu_common.virtio_common.paused_sync.clone();
 
-        let threads = self
-            .vu_common
-            .virtio_common
-            .epoll_threads
-            .get_or_insert_with(Vec::new);
-        spawn_virtio_thread(
+        self.vu_common.spawn_worker(
             &self.id,
             &self.seccomp_action,
             Thread::VirtioVhostNet,
-            threads,
             &self.exit_evt,
             device_status.clone(),
             interrupt_cb.clone(),