Here are some tools to validate that KVM is healthy on your hypervisor. (examples are Centos7 based)

[root@jen-master ~]# egrep -c ‘(svm|vmx)’ /proc/cpuinfo
16

[root@jen-master ~]# lscpu | grep Virtualization
Virtualization:        VT-x
Virtualization type:   full

[root@jen-master ~]# lsmod | grep -i kvm
kvm_intel             183720  0
kvm                   578558  1 kvm_intel
irqbypass              13503  1 kvm

There is also virt-host-validate (which I needed to install)

# yum install libvirt-client
# virt-host-validate

Ubuntu only:
# apt install cpu-checker
# kvm-ok