Introduction¶
In KVM4NFV project, we focus on the KVM hypervisor to enhance it for NFV, by looking at the following areas initially
- Minimal Interrupt latency variation for data plane VNFs:
- Minimal Timing Variation for Timing correctness of real-time VNFs
- Minimal packet latency variation for data-plane VNFs
Inter-VM communication,
Fast live migration
Configuration of Cyclictest¶
Cyclictest measures Latency of response to a stimulus. Achieving low latency with the KVM4NFV project requires setting up a special test environment. This environment includes the BIOS settings, kernel configuration, kernel parameters and the run-time environment.
- For more information regarding the test environment, please visit https://wiki.opnfv.org/display/kvm/KVM4NFV+Test++Environment https://wiki.opnfv.org/display/kvm/Nfv-kvm-tuning
Pre-configuration activities¶
Intel POD1 is currently used as OPNFV-KVM4NFV test environment. The latest build packages are downloaded onto Intel Pod1-jump server from artifact repository. Yardstick running in a ubuntu docker container on Intel Pod1-jump server will trigger the cyclictest.
Running cyclictest through Yardstick will Configure the host(Pod1-node1), the guest, executes cyclictest on the guest.
The following scripts are used for configuring host and guest to create a special test environment and achieve low latency.
host-setup0.sh: On running this script will install latest kernel rpm on host and will make necessary changes as following to create special test environment
- Isolates CPUs from the general scheduler
- Stops timer ticks on isolated CPUs whenever possible
- Stops RCU callbacks on isolated CPUs
- Enables intel iommu driver and disables DMA translation for devices
- Sets HugeTLB pages to 1GB
- Disables machine check
- Disables clocksource verification at runtime
host-setup1.sh: On running this script will make following test environment changes
- Disabling watchdogs to reduce overhead
- Disabling RT throttling
- Reroute interrupts bound to isolated CPUs to CPU 0
- Change the iptable so that we can ssh to the guest remotely
- host-run-qemu.sh: On running this script will launch a guest vm on host.
- Note: download guest disk image from artifactory
guest-setup0.sh: On running this scrcipt on guest vm will install the latest build kernel rpm, cyclictest and makes following configuration on guest vm.
- Isolates CPUs from the general scheduler
- Stops timer ticks on isolated CPUs whenever possible
- Uses polling idle loop to improve performance
- Disables clocksource verification at runtime
guest-setup1.sh: On running this script on guest vm will make following configurations
- Disable watchdogs to reduce overhead
- Routes device interrupts to non-RT CPU
- Disables RT throttling
Hardware configuration¶
Currently Intel POD1 is used as test environment for kvmfornfv to execute cyclictest. As part of this test environment Intel pod1-jump is configured as jenkins slave and all the latest build artifacts are downloaded on to it. Intel pod1-node1 is the host on which a guest vm will be launched as a part of running cylictest through yardstick.
- For more information regarding hardware configuration, please visit https://wiki.opnfv.org/display/pharos/Intel+Pod1 https://build.opnfv.org/ci/computer/intel-pod1/ http://artifacts.opnfv.org/octopus/brahmaputra/docs/octopus_docs/opnfv-jenkins-slave-connection.html