How do you create HVM AMI images on EC2?
I've searched a bit, it seems I am only able to create a paravirtualization AMI image, which means it cannot be applied on the HVM-based instances.
FYI, I'm using spot-instances only.
The instance you are taking the AMI of has to be hvm. In the case it is a PV instance, you must first turn it into an HVM, which essentially means starting from scratch on the build of the instance (there is a way to convert it, but I was unsuccessful at it: see here). Then once you have an HVM image, you should be able to launch an hvm instance.