Maybe I should ask in another way. How do I go and change the harddrive drivers to VirtIO drivers?
do you face any specific error messages - those would be the hints we need to point you in the right direction.
Basically, if the standard SLES kernel is used, it will already have everything included that’s needed to handle the virtual disks. It may of course be that they’re presented differently to your VM, but the consequences (and hence the required fixes) highly depend on your current setup. I.e. mounting file systems via volume name (LABEL= in fstab) should still work, while referencing the disk by path will most likely fail.