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idata
Community Manager
2,559 Views

What is the specific functionality of a PF(Physical Function) in SR-IOV ? Also what is the difference between virtual function and a physical function ? Does the VF communicate with a PF during the transfer of a packet from the VM ?

What is the specific functionality of a PF(Physical Function) in SR-IOV ? Also what is the difference between virtual function and a physical function ? Does the VF communicate with a PF during the transfer of a packet from the VM ?@

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idata
Community Manager
848 Views

Hi Ygkumar,

 

 

Thank you for the post.

 

 

1) The specific funtionality of a PF in SR-IOV is actually refers to the physical NIC that includes the full feature of the PCI-e functions, it is to configure and manage the SR-IOV.

 

.You may refer to page 13 at

 

http://www.intel.com/content/www/us/en/pci-express/pci-sig-sr-iov-primer-sr-iov-technology-paper.htm...

 

 

2) The difference between virtual function and physical function as follow:

 

(based on page 13 of the website above)

 

 

-Physical Functions (PFs): These are full PCIe functions that include the SR-IOV, Extended Capability. The capability is used to configure and manage the SR-IOV functionality.

 

- Virtual Functions (VFs): These are 'lightweight' PCIe functions that contain the resources necessary for data movement but have a carefully minimized set of configuration resources (this is the virtual NIC)

 

 

 

3) You may refer to page 12, the sample shows that the 3 virtual machines are directly accessing to dedicated resources within the ethernet controller without passing the PF.

 

http://www.intel.com/content/www/us/en/pci-express/pci-sig-sr-iov-primer-sr-iov-technology-paper.htm...

 

 

Thanks,

 

wb

 

idata
Community Manager
848 Views

Hi Ygkumar,

 

 

Good day. Please feel free to update me if further assistance needed?

 

 

rgds,

 

wb

 

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