PCIe devices are reported as non-pass-through capable or SR-IOV fails to enable

Products

• VMware vSphere ESXi 8.0

Issue/Introduction

• Some PCIe devices may be incorrectly reported and treated as non-pass-through capable, or SR-IOV virtual functions can not be enabled after installing or upgrading to ESXi 8.0.3.
• Devices that were reported as pass-through capable or were able to successfully enable SR-IOV virtual functions on earlier versions of ESXi 8.x may be incorrectly reported and treated as non-pass-through capable in ESXi 8.0.3.

Environment

vSphere ESXi 8.0.3

Cause

PCIE devices may be marked as non-pass-through capable, or SR-IOV may fail to enable due to overly strict sanity checking of ACS hardware configuration across the PCIe hierarchy when determining if pass-through/VFs can be enabled.

Resolution

This is a known issue impacting vSphere ESXi 8.x and will be fixed in a future release.

To work around the issue :

Set the boot option disableACSCheck = TRUE and reboot the ESXi host as per the steps below :

1. Migrate VMs and place the host in maintenance mode.
2. Navigate to the Configure tab of Host.
3. Navigate to System on the middle pane and click on Advanced System Settings.
4. Click on Edit.
5. Add the following parameter: VMkernel.Boot.disableACSCheck and set the value to TRUE
6. Reboot the host.

Even though the option disableACSCheck is set to TRUE, ACS will still be enabled, but the overly strict check will be skipped, and PCIe pass-through will be allowed.