EVC Mode displayed without Per-VM EVC mode or Cluster level EVC mode enabled

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:

• EVC Mode displayed without EVC.
• Per-VM EVC mode is not configured in VM(s).
• Cluster-level EVC mode is not configured.
• Virtual machine reports "EVC Mode" data in vSphere Web Client.

Environment

VMware vCenter Server Appliance 6.7.x
VMware vCenter Server 8.0.x
VMware vCenter Server 7.0.x
VMware vCenter Server 6.7.x

Cause

If Per-VM EVC mode is not enabled, and the ESXi host is either not part of a cluster, or part of a cluster without EVC Mode enabled, the "EVC Mode" for the virtual machine should match the ESXi host's available CPU Instruction set. This "EVC Mode" information is provided to determine the minimum supported host that the VM can be vMotioned to.

Resolution

This is expected behavior.

This 'EVC Mode' is visible on all powered on VMs from vSphere 6.7, whether or not the VMs are in a cluster with a configured EVC baseline, and whether or not the VMs have per-VM-EVC mode configured. The 'EVC Mode' is reporting what CPU features are exposed to the Guest operating system, and the minimum CPU instruction set needed for vMotion.

The EVC setting that is shown when a VM is powered on is what EVC mode is the minimum the VM can enter.

Examples : 

• If the VM is on a Broadwell host and power on, it will display "EVC Broadwell". This VM can't migrate to a host less than Broadwell, nor enter an EVC cluster less than Broadwell.
• If the VM is on a Skylake host and power on, it will display "EVC Skylake". This VM can't migrate to a host less than Skylake, nor enter an EVC cluster less than Skylake.
• If the VM is on an Ice Lake host and power on, it will display "EVC Ice Lake". This VM can't migrate to a host less than Ice Lake, nor enter an EVC cluster less than Ice Lake.