10.9.4. Configuring a virtual machine for DPDK workloads

Procedure

1. Edit the VirtualMachine manifest to include information about the SR-IOV network interface, CPU topology, CRI-O annotations, and huge pages.

   Example VirtualMachine manifest:

   apiVersion: kubevirt.io/v1
   kind: VirtualMachine
   metadata:
     name: rhel-dpdk-vm
   spec:
     runStrategy: Always
     template:
       metadata:
         annotations:
           cpu-load-balancing.crio.io: disable 

   1

   
           cpu-quota.crio.io: disable 

   2

   
           irq-load-balancing.crio.io: disable 

   3

   
       spec:
         domain:
           cpu:
             sockets: 1 

   4

   
             cores: 5 

   5

   
             threads: 2
             dedicatedCpuPlacement: true
             isolateEmulatorThread: true
           interfaces:
             - masquerade: {}
               name: default
             - model: virtio
               name: nic-east
               pciAddress: '0000:07:00.0'
               sriov: {}
             networkInterfaceMultiqueue: true
             rng: {}
         memory:
           hugepages:
             pageSize: 1Gi 

   6

   
             guest: 8Gi
         networks:
           - name: default
             pod: {}
           - multus:
               networkName: dpdk-net 

   7

   
             name: nic-east
   # ...

   1

   This annotation specifies that load balancing is disabled for CPUs that are used by the container.

   2

   This annotation specifies that the CPU quota is disabled for CPUs that are used by the container.

   3

   This annotation specifies that Interrupt Request (IRQ) load balancing is disabled for CPUs that are used by the container.

   4

   The number of sockets inside the VM. This field must be set to 1 for the CPUs to be scheduled from the same Non-Uniform Memory Access (NUMA) node.

   5

   The number of cores inside the VM. This must be a value greater than or equal to 1. In this example, the VM is scheduled with 5 hyper-threads or 10 CPUs.

   6

   The size of the huge pages. The possible values for x86-64 architecture are 1Gi and 2Mi. In this example, the request is for 8 huge pages of size 1Gi.

   7

   The name of the SR-IOV NetworkAttachmentDefinition object.

2. Save and exit the editor.

3. Apply the VirtualMachine manifest:

   $ oc apply -f <file_name>.yaml

4. Configure the guest operating system. The following example shows the configuration steps for RHEL 9 operating system:

   1. Configure huge pages by using the GRUB bootloader command-line interface. In the following example, 8 1G huge pages are specified.

      $ grubby --update-kernel=ALL --args="default_hugepagesz=1GB hugepagesz=1G hugepages=8"

   2. To achieve low-latency tuning by using the cpu-partitioning profile in the TuneD application, run the following commands:

      $ dnf install -y tuned-profiles-cpu-partitioning

      $ echo isolated_cores=2-9 > /etc/tuned/cpu-partitioning-variables.conf

      The first two CPUs (0 and 1) are set aside for house keeping tasks and the rest are isolated for the DPDK application.

      $ tuned-adm profile cpu-partitioning

   3. Override the SR-IOV NIC driver by using the driverctl device driver control utility:

      $ dnf install -y driverctl

      $ driverctl set-override 0000:07:00.0 vfio-pci

5. Restart the VM to apply the changes.