Network I/O is processed by vhost threads, which are threads in the Quick Emulator (QEMU) user space. Vhost threads should be pinned to match the guest virtual CPU (vCPU) threads. We recommend pinning at least two CPUs for vhost threads, which allows these threads to run on the same subset of physical CPUs and memory, improving system performance. This sample XML configuration pins CPUs 0 and 2 to be used for vhost thread processing.