[CentOS] Centos 7 and qemu-kvm

Still trying to migrate to CentOS 7.

I used to use qemu-kvm on centos 6. tried to compile on
centos 7 and get error about undefined reference to timer_gettime
searching for that says basically use virt-manager

so I installed virt-manager - I have file images and those work.
some times I do directly to a USB connected disk.

I do not see how to do that in virt-manager ???

How do I use a device like /dev/sdh as my disk???

Thanks,

Jerry