SR-IOV Hardware Not Available Message When Moving VMs Between Environments

Products

VMware vSphere ESXi

Issue/Introduction

When migrating virtual machines from an environment that supports SR-IOV (Single Root I/O Virtualization) to an environment that does not have this capability, network connectivity issues may occur with the message "SR-IOV hardware not available" displayed in the VM settings.

SR-IOV is a hardware virtualization technology that allows a single physical network adapter to be divided into multiple virtual functions that can be directly assigned to VMs. This provides near-native network performance by allowing VMs to bypass the hypervisor's networking stack through direct hardware access.

The message "SR-IOV hardware not available" after migration indicates that the destination environment doesn't support the passthrough network adapter configuration used in the source environment as seen below.

Steps to validate:

Observe "SR-IOV hardware not available" message in VM settings under Network Adapter Type
Network adapter shows as disconnected in VM settings
VM network interface shows no connectivity
Attempts to ping the gateway or other network resources from the VM fail
PCI Device passthrough is still selected as the adapter type

Environment

VMware vSphere ESXi
VMware vCenter Server
VMs previously using direct I/O or passthrough and now using VMXNET3 network adapters

Cause

This issue occurs when:

VMs are migrated from an environment where SR-IOV is configured and supported on the physical NICs
To an environment where the physical network adapters or infrastructure do not support SR-IOV capabilities
The VM is still configured to use PCI Device passthrough as the adapter type
The VM network adapter shows as disconnected because the required hardware capability is missing

When the destination environment doesn't support SR-IOV, the passthrough adapter cannot function properly, leading to network connectivity failure for the affected VMs.

Resolution

Change the network adapter type from PCI Device passthrough to VMXNET3:
- Power off the VM
- Edit the VM settings
- Expand the network adapter settings
- Change the "Adapter Type" from "PCI Device passthrough" to "VMXNET3"
- Ensure the correct port group is selected
- Select "Connected" and "Connect at power on"
- Click OK to save changes
- Power on the VM
Verify network configuration within the guest OS:
- Remove any previous VLAN tagging configurations from the guest OS
- Reset network adapter settings if necessary
- Verify IP address configuration
Ensure the physical network infrastructure is properly configured:
- Confirm with the network team that the physical switch ports are no longer configured for SR-IOV
- Verify the port configuration matches the standard virtual networking requirements
- Ensure that VLANs are properly configured on the virtual switch/port groups instead of relying on guest OS tagging

The key difference to understand is that with SR-IOV, VLAN tagging and network processing occur at the physical NIC level or within the guest OS. After migration to a non-SR-IOV environment, these functions must be handled by the virtual switch instead.

If the error persists after following these steps, contact Broadcom Support for further assistance.

Make sure when opening a case with Broadcom for this concern to upload ESXi host logs to the case, please see the following links for more information: