libkrun v1.17.5 - vsock Queue Overflow Fixes

🎉 libkrun v1.17.5

vsock Queue Overflow Fixes

This release resolves critical vsock queue overflow issues that caused network stalls under heavy load.

Key Fixes

vsock Queue Management:

• Fix queue overflow when container applications perform heavy network communication
• Implement backpressure mechanism with rx_ready_fd signaling
• Add paused_proxies queue to prevent CPU busy-loops
• Fix CreditUpdate logic to only update on successful packet push

Flow Control:

• Prevent flow control deadlocks in credit-based flow control
• Add proper signaling when RX queue space becomes available
• Implement level-triggered epoll handling to avoid busy-loops

Code Quality:

• Add missing AsRawFd imports in balloon and rng event handlers
• Add detailed error logging for queue overflow scenarios

Verification

• ✅ nginx container test: 10/10 requests successful
• ✅ No queue overflow errors under load
• ✅ Stable network communication
• ✅ Proper backpressure handling

Files Changed

• src/devices/src/virtio/vsock/muxer.rs
• src/devices/src/virtio/vsock/muxer_thread.rs
• src/devices/src/virtio/vsock/event_handler.rs
• src/devices/src/virtio/vsock/tsi_stream.rs
• src/devices/src/virtio/vsock/unix.rs
• src/devices/src/virtio/vsock/proxy.rs
• src/devices/src/virtio/balloon/event_handler.rs
• src/devices/src/virtio/rng/event_handler.rs

Upgrade Notes

This is a recommended upgrade for all users experiencing network stalls or high CPU usage in vsock communication.