6.5.1

Table Of Contents
Figure 101. Data and Configuration Paths in the SR-IOV Support of vSphere
IOMMU
PCI Express
Physical network adapter with SR-IOV
PCI Express
Physical network adapter without SR-IOV
Port group
Uplink port
Port association
Data path
Control path
Port group
Uplink port
VMware ESXi
Virtual Switch
Virtual Switch
VM
VM
1
3 4
2 5
VM
VF driver
VM
VF driver
PF
PF driver
PF driver
VF
VF
PF
Data Path in SR-IOV
After the virtual machine network adapter is assigned to a virtual function, the VF driver in the guest
operating system uses the I/O memory management unit (IOMMU) technology to access the virtual
function that must receive or send the data over the network. The VMkernel, that is, the virtual switch in
particular, does not process the data flow, which reduces the overall latency of SR-IOV enabled
workloads.
Configuration Path in SR-IOV
If the guest operating system attempts to change the configuration of a virtual machine adapter mapped
to a VF, the change takes place if it is allowed by the policy on the port associated with the virtual
machine adapter.
The configuration workflow consists of the following operations:
1 The guest operating system requests a configuration change on the VF.
vSphere Networking
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