SR-IOV Configuration of number of Virtual Functions always results in TotalVFs for a device

Products

• VMware vSphere ESXi

Issue/Introduction

To explain a limitation created by legacy Native DDK drivers and to educate the customers so that they can upgrade their hosts if needed.

Symptoms:
The configured number of Virtual Functions for an SR-IOV device is equal to the maximum number of Virtual Functions for a device (TotalVFs), even if the value is specified in vSphere Host Client UI or vCenter UI is lower.

Environment

VMware ESXi 6.5.x

Cause

Legacy Native DDK drivers (ESXi 6.5 and older) that do not implement support for querying the configured MaxVFs value via the vmk_DeviceGetParamMaxVfs API will exhibit this issue.

Resolution

To resolve this issue, use a Native DDK driver that implements vmk_DeviceGetParamMaxVfs

Workaround:
Please see the vendor specific setup guide for configuring SR-IOV.