cloud2:~# LIBVIRT_DEBUG=1 virsh -c "qemu:///system" list
08:12:17.322: 25752: debug : virInitialize:340 : register drivers
08:12:17.322: 25752: debug : virRegisterDriver:942 : registering Test as driver 0
08:12:17.322: 25752: debug : virRegisterNetworkDriver:748 : registering Test as network driver 0
08:12:17.322: 25752: debug : virRegisterInterfaceDriver:779 : registering Test as interface driver 0
08:12:17.322: 25752: debug : virRegisterStorageDriver:810 : registering Test as storage driver 0
08:12:17.322: 25752: debug : virRegisterDeviceMonitor:841 : registering Test as device driver 0
08:12:17.322: 25752: debug : virRegisterSecretDriver:872 : registering Test as secret driver 0
08:12:17.322: 25752: debug : virRegisterNWFilterDriver:903 : registering Test as network filter driver 0
08:12:17.322: 25752: debug : virRegisterDriver:942 : registering Xen as driver 1
08:12:17.322: 25752: debug : virRegisterDriver:942 : registering OPENVZ as driver 2
08:12:17.322: 25752: debug : virRegisterDriver:942 : registering PHYP as driver 3
08:12:17.322: 25752: debug : virRegisterStorageDriver:810 : registering PHYP as storage driver 1
08:12:17.322: 25752: debug : virRegisterNetworkDriver:748 : registering PHYP as network driver 1
08:12:17.322: 25752: debug : vboxRegister:122 : VBoxCGlueInit failed, using dummy driver
08:12:17.322: 25752: debug : virRegisterDriver:942 : registering VBOX as driver 4
08:12:17.322: 25752: debug : virRegisterNetworkDriver:748 : registering VBOX as network driver 2
08:12:17.322: 25752: debug : virRegisterStorageDriver:810 : registering VBOX as storage driver 2
08:12:17.322: 25752: debug : virRegisterDriver:942 : registering ESX as driver 5
08:12:17.322: 25752: debug : virRegisterInterfaceDriver:779 : registering ESX as interface driver 1
08:12:17.322: 25752: debug : virRegisterNetworkDriver:748 : registering ESX as network driver 3
08:12:17.322: 25752: debug : virRegisterStorageDriver:810 : registering ESX as storage driver 3
08:12:17.322: 25752: debug : virRegisterDeviceMonitor:841 : registering ESX as device driver 1
08:12:17.322: 25752: debug : virRegisterSecretDriver:872 : registering ESX as secret driver 1
08:12:17.322: 25752: debug : virRegisterNWFilterDriver:903 : registering ESX as network filter driver 1
08:12:17.322: 25752: debug : virRegisterDriver:942 : registering remote as driver 6
08:12:17.322: 25752: debug : virRegisterNetworkDriver:748 : registering remote as network driver 4
08:12:17.322: 25752: debug : virRegisterInterfaceDriver:779 : registering remote as interface driver 2
08:12:17.322: 25752: debug : virRegisterStorageDriver:810 : registering remote as storage driver 4
08:12:17.322: 25752: debug : virRegisterDeviceMonitor:841 : registering remote as device driver 2
08:12:17.322: 25752: debug : virRegisterSecretDriver:872 : registering remote as secret driver 2
08:12:17.322: 25752: debug : virRegisterNWFilterDriver:903 : registering remote as network filter driver 2
08:12:17.322: 25752: debug : virConnectOpenAuth:1513 : name=qemu:///system, auth=0x7fbe43c9c340, flags=0
08:12:17.323: 25752: debug : do_open:1219 : name "qemu:///system" to URI components:
  scheme qemu
  opaque (null)
  authority (null)
  server (null)
  user (null)
  port 0
  path /system

08:12:17.323: 25752: debug : do_open:1258 : trying driver 0 (Test) ...
08:12:17.323: 25752: debug : do_open:1264 : driver 0 Test returned DECLINED
08:12:17.323: 25752: debug : do_open:1258 : trying driver 1 (Xen) ...
08:12:17.323: 25752: debug : do_open:1264 : driver 1 Xen returned DECLINED
08:12:17.323: 25752: debug : do_open:1258 : trying driver 2 (OPENVZ) ...
08:12:17.323: 25752: debug : do_open:1264 : driver 2 OPENVZ returned DECLINED
08:12:17.323: 25752: debug : do_open:1258 : trying driver 3 (PHYP) ...
08:12:17.323: 25752: debug : do_open:1264 : driver 3 PHYP returned DECLINED
08:12:17.323: 25752: debug : do_open:1258 : trying driver 4 (VBOX) ...
08:12:17.323: 25752: debug : do_open:1264 : driver 4 VBOX returned DECLINED
08:12:17.323: 25752: debug : do_open:1258 : trying driver 5 (ESX) ...
08:12:17.323: 25752: debug : do_open:1264 : driver 5 ESX returned DECLINED
08:12:17.323: 25752: debug : do_open:1258 : trying driver 6 (remote) ...
08:12:17.323: 25752: debug : doRemoteOpen:573 : proceeding with name = qemu:///system
08:12:17.323: 25752: debug : remoteIO:10280 : Do proc=66 serial=0 length=28 wait=(nil)
08:12:17.323: 25752: debug : remoteIO:10352 : We have the buck 66 0x7fbe3d71b010 0x7fbe3d71b010