Xen Summit 2026

Xen Argo provides a robust mechanism for inter-domain communication, offering strong isolation compared to traditional shared memory approaches. However, its message-based API creates a portability barrier for standard POSIX applications. In this session, I will present the realization of a new Linux kernel module that solves this challenge by implementing a complete VSOCK transport layer over Xen Argo. By exposing Argo through the standard AF_VSOCK interface, we enable existing socket-based applications to run over Argo channels, supporting both datagrams and reliable data streams (SOCK_STREAM) without code modification.
Building upon initial designs, we will dive deep into the kernel-level challenges to achieve a fully functional TCP-like stream over Argo's asynchronous rings. Key technical topics include:

Realizing the Connection-Oriented Handshake: Mapping the POSIX TCP state machine (SYN/SYN-ACK) onto Argo, including dynamic ring allocation with asymmetric hypervisor permissions to enable bidirectional traffic.

Socket multiplexing: allowing concurrent logical connections over a single ring, bypassing the strict 1:1 port-to-ring limitation.