yum groupinstall   "虚拟化"
yum groupinstall   "虚拟化客户端"
yum groupinstall   "虚拟化工具"
yum groupinstall   "虚拟化平台"
安装完后，重启主机 reboot
 ~]$ service libvirtd status
检查服务动运行状态
libvirtd (pid  2204) 正在运行...
~]# virt-manager
启动KVM，虚拟网络不活跃，手动启动，提示如下错误：
Error starting network 'default': internal error Child process (/usr/sbin/dnsmasq --strict-order --local=// --domain-needed --pid-file=/var/run/libvirt/network/default.pid --conf-file= --except-interface lo --bind-interfaces --listen-address 192.168.122.1 --dhcp-range 192.168.122.2,192.168.122.254 --dhcp-leasefile=/var/lib/libvirt/dnsmasq/default.leases --dhcp-lease-max=253 --dhcp-no-override --dhcp-hostsfile=/var/lib/libvirt/dnsmasq/default.hostsfile --addn-hosts=/var/lib/libvirt/dnsmasq/default.addnhosts) unexpected exit status 3:
dnsmasq: failed to open pidfile /var/run/libvirt/network/default.pid: Permission denied
更新了一下：yum updata selinux-policy  后解决！