→ Applies to: Hyperion 9.x and above

Symptom

After applying the Security Update KB5060842 (June 10, 2025), VMs running Windows 2025 or Windows 11 fail to start and display a blue screen error (BSOD) with the message “UNSUPPORTED PROCESSOR”.

This issue only occurs on appliances with AMD processors.
 

Solution

Step 1. Connect to Hyperion appliance via SSH as admin

ssh admin@<your_ip_address_or_hostname>

Step 2. Become Super User

sudo su

Step 3. List all VMs on the system

virsh list --all

EXAMPLE

Identify the name of the VM that reported the error.

Step 4. Shutdown the VM (replace <vm-name> with the correct information)

virsh shutdown <vm-name>

Step 5. Change the virtual CPU configuration (replace <vm-name> with the correct information)

VM=<vm-name>; \
virsh dumpxml "$VM" > /tmp/"$VM".xml && \
cp /tmp/"$VM".xml /tmp/"$VM".xml.bak && \
xmlstarlet ed -L \
  -u "/domain/cpu/@mode"               -v "custom" \
  -i "/domain/cpu"                     -t attr -n match    -v "exact" \
  -i "/domain/cpu/topology"           -t elem -n model    -v "EPYC-IBPB" \
  -i "/domain/cpu/model"               -t attr -n fallback -v "allow" \
  /tmp/"$VM".xml && \
virsh define /tmp/"$VM".xml