[root@localhost ~]# xl info
host                   : localhost
release                : 3.18.12-11.el7.x86_64
version                : #1 SMP Mon May 11 13:47:03 UTC 2015
machine                : x86_64
libxl: error: libxl.c:4322:libxl_get_physinfo: getting physinfo: Permission denied
libxl_physinfo failed.
libxl: error: libxl.c:4728:libxl_get_scheduler: getting domain info list: Permission denied
xen_major              : 4
xen_minor              : 6
xen_extra              : -unstable
xen_version            : 4.6-unstable
xen_caps               : xen-3.0-x86_64 xen-3.0-x86_32p hvm-3.0-x86_32 hvm-3.0-x86_32p hvm-3.0-x86_64
xen_scheduler          : (null)
xen_pagesize           : 4096
platform_params        : virt_start=0xffff800000000000
xen_changeset          : Thu May 7 16:23:28 2015 +0100 git:2fe90ef
xen_commandline        : placeholder conswitch=x watchdog com1=115200,8n1 console=com1,vga gdb=com1 dom0_mem=1024M,max:1024M sched=credit2
cc_compiler            : gcc (Debian 4.9.1-19) 4.9.1
cc_compile_by          : root
cc_compile_domain      : uk.xensource.com
cc_compile_date        : Thu May  7 16:39:27 BST 2015
xend_config_format     : 4
[root@localhost ~]# xl list
libxl: error: libxl.c:557:libxl_list_domain: geting domain info list: Permission denied
libxl_list_domain failed.