1.2. KVM Performance Architecture Overview

The following points provide a brief overview of KVM as it pertains to system performance, as well as process and thread management:
  • When using KVM, guests run as a Linux processes on the host.
  • Virtual CPUs (vCPUs) are implemented as normal threads, handled by the Linux scheduler.
  • Guests do not automatically inherit features such as NUMA and huge pages from the kernel.
  • Disk and network I/O settings in the host have a significant performance impact.
  • Network traffic typically travels through a software-based bridge.
  • Depending on the devices and their models, there might be significant overhead due to emulation of that particular hardware.