ESXi host fails to boot with "At least one CPU on this system has an APIC ID greater than 255, so interrupt remapping hardware is needed, but no such hardware is available."

Products

• VMware vSphere ESXi

Issue/Introduction

After installing or upgrading to the GA release of ESXi 8.0 u3, the host fails to boot with a purple screen displaying this message:

The system has found a problem on your machine and cannot continue.
Interrupt remapper error: Not initialized
At least one CPU on this system has an APIC ID greater than 255, so interrupt remapping hardware is needed, but no such hardware is available.



This may occur after enabling Secure Boot, even if the host booted normally before, and can persist even once Secure Boot is disabled.

Cause

This error occurs when multiple PCI segments are enabled in the BIOS. ESXi 8.0 u3 GA does not support multiple PCI segments for some newer processors, which prevents the interrupt remapping hardware from initializing properly. 

Resolution

Perform a fresh installation using an ISO for ESXi 8.0 u3g or newer on the impacted hosts. A fresh installation is preferable to an upgrade/update, as hosts that are upgraded from impacted versions have been observed to retain the error in some instances.