If a cloud provider doesn’t advertise their KVM virtualization then a strong chance they don’t have any KVM.
this.
Also Xen is the only alternative pretty much as good as KVM so unless you’re like Amazon AWS defending using Xen instead of KVM, there’s really no other virtualization as good as KVM these days so most cloud hosting companies should be bragging about having KVM.
if they’re not… they probably don’t offer it ($$)