[libvirt-users] libvirtd may need to be started: Permission denied

Hi, I try to configure libvirtd to use qemu+tcp, but after doing so, I can't use virsh or programs with libvirt API. I type "virsh -c qemu:///system", then error: unable to connect to '/var/run/libvirt/libvirt-sock', libvirtd may need to be started: Permission deniederror: failed to connect to the hypervisor I could add "sudo" to "virsh -c qemu:///system", running virsh with "qemu:///system" normally, but it's not suitable for my requests. Also I try to restart or reinstall libvirt-bin in Ubuntu, also failed. Could you give me some idea? Thanks a lot! RegardsCorey