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Centos Newbie
Asked: 2016-09-29 17:09:33 +0800 CST

Is vlan tagging on guest allowed in sr-iov on KVM?

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I am using KVM on Centos 7. I have created a VM with SR-IOV VFs to pass traffic. I notice that I am unable to pass traffic when I tag the interface inside the VM. I have read through the internet and the data sheet from Intel but none give me a clear picture of how it is done.

Server1

Eth0 - PF

SR-IOV Enabled

eth0-vf-1 (Attached to VM)

[Inside the VM]

Centos 7

eth0.100

Server2

Eth0 - PF

SR-IOV Enabled

eth0-vf-1 (Attached to VM)

[Inside the VM]

Centos 7

eth0.100

Switch

Extreme Networks

VLAN tagged 100

Port 1,2

Port 1 - Server 1 - Eth0 - PF

Port 2 - Server 2 - Eth0 - PF

Can anyone guide me through this? I would like to know if anyone has tried such a configuration or would this not be the best used case for SR-IOV?

I did find one issue here but did not understand much. Thank you community.

vlan kvm-virtualization sr-iov

1 Answers

  1. Best Answer

    I checked, and it looks like with VFs, the tagging needs to be done on the host, via libvirt. The way this looks in the domxml is as follows

    <interface type='hostdev' managed='yes'>                                                         
  <mac address=' fa:aa:aa:aa:aa:aa '/>                                                              
  <driver name='kvm'/>                                                                           
  <source>                                                                                       
    <address type='pci' domain='0x0000' bus='0x02' slot='0x00' function='0x7'/>                  
  </source>                                                                                      
  <vlan>                                                                                          
    <tag id='190'/>                                                                              
  </vlan>
  <alias name='hostdev0'/>
  <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
</interface>

    Link: https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Virtualization_Host_Configuration_and_Guest_Installation_Guide/sect-Virtualization_Host_Configuration_and_Guest_Installation_Guide-SR_IOV-How_SR_IOV_Libvirt_Works.html

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