constants: add HT_KVM

Add a new hypervisor type, HT_KVM, to constants, and register it in the
HYPER_TYPES set.

Reviewed-by: imsnah

lib/constants.py

@@ -235,7 +235,8 @@ INSTANCE_REBOOT_FULL = "full"
 HT_XEN_PVM30 = "xen-3.0"
 HT_FAKE = "fake"
 HT_XEN_HVM31 = "xen-hvm-3.1"
-HYPER_TYPES = frozenset([HT_XEN_PVM30, HT_FAKE, HT_XEN_HVM31])
+HT_KVM = "kvm"
+HYPER_TYPES = frozenset([HT_XEN_PVM30, HT_FAKE, HT_XEN_HVM31, HT_KVM])
 HTS_REQ_PORT = frozenset([HT_XEN_HVM31])
 
 HT_HVM_VNC_BASE_PORT = 5900