ESXI Homelab Disable Spectre/Meltdown/SSBD

disable_mitigations.md

ESXI Mitigations Disable

I recommend this only be done on homelab/segmented hardware. This will make your host vulnerable to these exploits.

Depending on your CPU generation, you can regain 20-30% performance.

Spectre/Meltdown

Ref1

1. SSH to ESXI Host
2. vi /etc/vmware/config
3. add the line:

Version 1 (Spectrev4/Meltdown/Spectre)

cpuid.7.edx = "0---:00--:----:----:----:----:----:----"

Version 2 (Spectre only)

cpuid.7.edx = "0---:----:----:----:----:----:----:----"

4. Run /sbin/auto-backup.sh to ensure config is re-applied on boot

Disable SSBD

Ref

1. SSH to ESXI Host

2. Check settings

   esxcli system settings kernel list -o hyperthreadingMitigation
   esxcli system settings kernel list -o hyperthreadingMitigationIntraVM
   

3. Enable v2 Scheduler (90-100% of performance):

   esxcli system settings kernel set -s hyperthreadingMitigation -v TRUE
   esxcli system settings kernel set -s hyperthreadingMitigationIntraVM -v FALSE
   

Option B (fully disabled, 100% perf):

esxcli system settings kernel set -s hyperthreadingMitigation -v FALSE
esxcli system settings kernel set -s hyperthreadingMitigationIntraVM -v FALSE