sonic-buildimage/platform/vs

HOWTO Use Virtual Switch (VM)

1. Install libvirt, kvm, qemu

sudo apt-get install libvirt-clients qemu-kvm libvirt-bin

2. Create SONiC VM for single ASIC HWSKU

$ sudo virsh
Welcome to virsh, the virtualization interactive terminal.

Type:  'help' for help with commands
       'quit' to quit

virsh # 
virsh # create sonic.xml
Domain sonic created from sonic.xml

virsh # 

2. Create SONiC VM for multi-ASIC HWSKU

• Based on the number of asics of hwsku, update device/x86_64-kvm_x86_64-r0/asic.conf

NUM_ASIC=<n>
DEV_ID_ASIC_0=0
DEV_ID_ASIC_1=1
DEV_ID_ASIC_2=2
DEV_ID_ASIC_3=3
..
DEV_ID_ASIC_<n-1>=<n-1>

For example, a four asic VS asic.conf will be:

NUM_ASIC=4
DEV_ID_ASIC_0=0
DEV_ID_ASIC_1=1
DEV_ID_ASIC_2=2
DEV_ID_ASIC_3=3

• Create a topology.sh script which will create the internal asic topology for the specific hwsku. For example, for msft_multi_asic_vs: https://github.com/Azure/sonic-buildimage/blob/master/device/virtual/x86_64-kvm_x86_64-r0/msft_multi_asic_vs/topology.sh

• With the updated asic.conf and topology.sh, build sonic-vs.img which can be used to bring up multi-asic virtual switch.

• Update platform/vs/sonic_multiasic.xml with higher memory and vcpu as required.

  • For 4-asic vs platform msft_four_asic_vs hwsku, 8GB memory and 10vCPUs.
  • For 7-ASIC vs platform msft_multi_asic_vs hwsku, 8GB and 16vCPUs.

• Update the number of front-panel interfaces in sonic_multliasic.xml

  • For 4-ASIC vs platform, 8 front panel interfaces.
  • For 6-ASIC vs platform, 64 front panel interfaces.

• With multi-asic sonic_vs.img and sonic_multiasic.xml file, bring up multi-asic vs as:

$ sudo virsh
Welcome to virsh, the virtualization interactive terminal.

Type:  'help' for help with commands
       'quit' to quit

virsh #
virsh # create sonic_multiasic.xml 
Domain sonic created from sonic.xml

virsh #

• Steps to convert a prebuilt single asic sonic-vs.img:

  • Use the updated sonic_multiasic.xml file and bring up virtual switch.
  • Update /usr/share/sonic/device/x86_64-kvm_x86_64-r0/asic.conf as above.
  • Add topology.sh in /usr/share/sonic/device/x86_64-kvm_x86_64-r0/
  • stop database service and remove database docker, so that when vs is rebooted, database_global.json is created with the right namespaces.
    • systemctl stop database
    • docker rm database
  • sudo reboot
  • Once rebooted, VS should be multi-asic VS.

• Start topology service.

sudo systemctl start topology.

• Load configuration using minigraph or config_dbs.

3. Access virtual switch:

   1. Connect SONiC VM via console

   $ telnet 127.0.0.1 7000
   

   OR

   2. Connect SONiC VM via SSH

      1. Connect via console (see 3.1 above)

      2. Request a new DHCP address

      sudo dhclient -v
      

      3. Connect via SSH

      $ ssh -p 3040 admin@127.0.0.1