DPDK 支持¶
该文档介绍 Kube-OVN 如何和 OVS-DPDK 结合，给 KubeVirt 的虚机提供 DPDK 类型的网络接口。
上游的 KubeVirt 目前还未支持 OVS-DPDK，用户需要自己通过相关 patch Vhostuser implementation 构建 KubeVirt 或 KVM Device Plugin 来使用 OVS-DPDK。
前提条件¶
- 节点需提供专门给 DPDK 驱动运行的网卡。
- 节点需开启 Hugepages。
网卡设置 DPDK 驱动¶
这里我们使用 driverctl 为例进行操作，具体参数和其他驱动使用请参考 DPDK 文档进行操作。
driverctl set-override 0000:00:0b.0 uio_pci_generic
节点配置¶
对支持 OVS-DPDK 的节点打标签，以便 Kube-OVN 进行识别处理：
kubectl label nodes <node> ovn.kubernetes.io/ovs_dp_type="userspace"
在支持 OVS-DPDK 节点的 /opt/ovs-config 目录下创建配置文件 ovs-dpdk-config：
ENCAP_IP=192.168.122.193/24
DPDK_DEV=0000:00:0b.0
ENCAP_IP: 隧道端点地址。DPDK_DEV: 设备的 PCI ID。
安装 Kube-OVN¶
下载安装脚本：
wget https://raw.githubusercontent.com/kubeovn/kube-ovn/release-1.12/dist/images/install.sh
启用 DPDK 安装选项进行安装：
bash install.sh --with-hybrid-dpdk
使用方式¶
这里我们通过创建一个使用 vhostuser 类型网卡的虚机来验证 OVS-DPDK 功能。
安装 KVM Device Plugin 来创建虚机，更多使用方式请参考 KVM Device Plugin。
kubectl apply -f https://raw.githubusercontent.com/kubevirt/kubernetes-device-plugins/master/manifests/kvm-ds.yml
创建 NetworkAttachmentDefinition：
apiVersion: k8s.cni.cncf.io/v1
kind: NetworkAttachmentDefinition
metadata:
name: ovn-dpdk
namespace: default
spec:
config: >-
{
"cniVersion": "0.3.0",
"type": "kube-ovn",
"server_socket": "/run/openvswitch/kube-ovn-daemon.sock",
"provider": "ovn-dpdk.default.ovn",
"vhost_user_socket_volume_name": "vhostuser-sockets",
"vhost_user_socket_name": "sock"
}
使用下面的 Dockerfile 创建 VM 镜像：
FROM quay.io/kubevirt/virt-launcher:v0.46.1
# wget http://cloud.centos.org/centos/7/images/CentOS-7-x86_64-GenericCloud.qcow2
COPY CentOS-7-x86_64-GenericCloud.qcow2 /var/lib/libvirt/images/CentOS-7-x86_64-GenericCloud.qcow2
创建虚拟机：
apiVersion: v1
kind: ConfigMap
metadata:
name: vm-config
data:
start.sh: |
chmod u+w /etc/libvirt/qemu.conf
echo "hugetlbfs_mount = \"/dev/hugepages\"" >> /etc/libvirt/qemu.conf
virtlogd &
libvirtd &
mkdir /var/lock
sleep 5
virsh define /root/vm/vm.xml
virsh start vm
tail -f /dev/null
vm.xml: |
<domain type='kvm'>
<name>vm</name>
<uuid>4a9b3f53-fa2a-47f3-a757-dd87720d9d1d</uuid>
<memory unit='KiB'>2097152</memory>
<currentMemory unit='KiB'>2097152</currentMemory>
<memoryBacking>
<hugepages>
<page size='2' unit='M' nodeset='0'/>
</hugepages>
</memoryBacking>
<vcpu placement='static'>2</vcpu>
<cputune>
<shares>4096</shares>
<vcpupin vcpu='0' cpuset='4'/>
<vcpupin vcpu='1' cpuset='5'/>
<emulatorpin cpuset='1,3'/>
</cputune>
<os>
<type arch='x86_64' machine='pc'>hvm</type>
<boot dev='hd'/>
</os>
<features>
<acpi/>
<apic/>
</features>
<cpu mode='host-model'>
<model fallback='allow'/>
<topology sockets='1' cores='2' threads='1'/>
<numa>
<cell id='0' cpus='0-1' memory='2097152' unit='KiB' memAccess='shared'/>
</numa>
</cpu>
<on_reboot>restart</on_reboot>
<devices>
<emulator>/usr/libexec/qemu-kvm</emulator>
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2' cache='none'/>
<source file='/var/lib/libvirt/images/CentOS-7-x86_64-GenericCloud.qcow2'/>
<target dev='vda' bus='virtio'/>
</disk>
<interface type='vhostuser'>
<mac address='00:00:00:0A:30:89'/>
<source type='unix' path='/var/run/vm/sock' mode='server'/>
<model type='virtio'/>
<driver queues='2'>
<host mrg_rxbuf='off'/>
</driver>
</interface>
<serial type='pty'>
<target type='isa-serial' port='0'>
<model name='isa-serial'/>
</target>
</serial>
<console type='pty'>
<target type='serial' port='0'/>
</console>
<channel type='unix'>
<source mode='bind' path='/var/lib/libvirt/qemu/channel/target/domain-1-vm/org.qemu.guest_agent.0'/>
<target type='virtio' name='org.qemu.guest_agent.0' state='connected'/>
<alias name='channel0'/>
<address type='virtio-serial' controller='0' bus='0' port='1'/>
</channel>
</devices>
</domain>
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: vm-deployment
labels:
app: vm
spec:
replicas: 1
selector:
matchLabels:
app: vm
template:
metadata:
labels:
app: vm
annotations:
k8s.v1.cni.cncf.io/networks: default/ovn-dpdk
ovn-dpdk.default.ovn.kubernetes.io/ip_address: 10.16.0.96
ovn-dpdk.default.ovn.kubernetes.io/mac_address: 00:00:00:0A:30:89
spec:
nodeSelector:
ovn.kubernetes.io/ovs_dp_type: userspace
securityContext:
runAsUser: 0
volumes:
- name: vhostuser-sockets
emptyDir: {}
- name: xml
configMap:
name: vm-config
- name: hugepage
emptyDir:
medium: HugePages-2Mi
- name: libvirt-runtime
emptyDir: {}
containers:
- name: vm
image: vm-vhostuser:latest
command: ["bash", "/root/vm/start.sh"]
securityContext:
capabilities:
add:
- NET_BIND_SERVICE
- SYS_NICE
- NET_RAW
- NET_ADMIN
privileged: false
runAsUser: 0
resources:
limits:
cpu: '2'
devices.kubevirt.io/kvm: '1'
memory: '8784969729'
hugepages-2Mi: 2Gi
requests:
cpu: 666m
devices.kubevirt.io/kvm: '1'
ephemeral-storage: 50M
memory: '4490002433'
volumeMounts:
- name: vhostuser-sockets
mountPath: /var/run/vm
- name: xml
mountPath: /root/vm/
- mountPath: /dev/hugepages
name: hugepage
- name: libvirt-runtime
mountPath: /var/run/libvirt
等待虚拟机创建成功后进入 Pod 进行虚机配置：
# virsh set-user-password vm root 12345
Password set successfully for root in vm
# virsh console vm
Connected to domain 'vm'
Escape character is ^] (Ctrl + ])
CentOS Linux 7 (Core)
Kernel 3.10.0-1127.el7.x86_64 on an x86_64
localhost login: root
Password:
Last login: Fri Feb 25 09:52:54 on ttyS0
接下来可以登录虚机进行网络配置并测试：
ip link set eth0 mtu 1400
ip addr add 10.16.0.96/16 dev eth0
ip ro add default via 10.16.0.1
ping 114.114.114.114
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