VM with more than 128 vCPUs

Hi,

I need to add vCPUs to a VM. This will exceed 128 so I’m getting this message “The firmware boot option setting has been automatically changed from BIOS  to EFI as well as I/O MMU has been enabled to allow for the specified CPU”.

I can’t find any information about this message on the net so I’m wondering what the consequences are for my VM / OS. Do I have to change anything on the OS level ? What are the risks for my machine ?

(FYI: ESXi 6.7 U2 / VM SLES 12)

Thanks a lot for your future replies.

Eric.