--- /dev/null
+KVM VMs vhost-user
+------------------
+
+FD.io CSIT performance lab is testing VPP vhost with KVM VMs using
+following environment settings:
+
+- Tests with varying Qemu virtio queue (a.k.a. vring) sizes: [vr256]
+ default 256 descriptors, [vr1024] 1024 descriptors to optimize for
+ packet throughput.
+- Tests with varying Linux :abbr:`CFS (Completely Fair Scheduler)`
+ settings: [cfs] default settings, [cfsrr1] CFS RoundRobin(1) policy
+ applied to all data plane threads handling test packet path including
+ all VPP worker threads and all Qemu testpmd poll-mode threads.
+- Resulting test cases are all combinations with [vr256,vr1024] and
+ [cfs,cfsrr1] settings.
+- Adjusted Linux kernel :abbr:`CFS (Completely Fair Scheduler)`
+ scheduler policy for data plane threads used in CSIT is documented in
+ `CSIT Performance Environment Tuning wiki
+ <https://wiki.fd.io/view/CSIT/csit-perf-env-tuning-ubuntu1604>`_.
+- The purpose is to verify performance impact (MRR and NDR/PDR
+ throughput) and same test measurements repeatability, by making VPP
+ and VM data plane threads less susceptible to other Linux OS system
+ tasks hijacking CPU cores running those data plane threads.