enable cgroup cpuset by default

This prepares for subsequent patches which introduce dependence
on cgroup cpuset. Enable cgroup cpuset by default so users don't
have to modify configuration file before encountering a cpuset
error.

src/qemu/qemu.conf

@@ -157,18 +157,19 @@
 #  - 'devices' - use for device whitelisting
 #  - 'memory' - use for memory tunables
 #  - 'blkio' - use for block devices I/O tunables
+#  - 'cpuset' - use for CPUs and memory nodes
 #
 # NB, even if configured here, they won't be used unless
 # the administrator has mounted cgroups, e.g.:
 #
 #  mkdir /dev/cgroup
-#  mount -t cgroup -o devices,cpu,memory,blkio none /dev/cgroup
+#  mount -t cgroup -o devices,cpu,memory,blkio,cpuset none /dev/cgroup
 #
 # They can be mounted anywhere, and different controllers
 # can be mounted in different locations. libvirt will detect
 # where they are located.
 #
-# cgroup_controllers = [ "cpu", "devices", "memory", "blkio" ]
+# cgroup_controllers = [ "cpu", "devices", "memory", "blkio", "cpuset" ]
 
 # This is the basic set of devices allowed / required by
 # all virtual machines.

src/qemu/qemu_conf.c

@@ -303,7 +303,8 @@ int qemudLoadDriverConfig(struct qemud_driver *driver,
             (1 << VIR_CGROUP_CONTROLLER_CPU) |
             (1 << VIR_CGROUP_CONTROLLER_DEVICES) |
             (1 << VIR_CGROUP_CONTROLLER_MEMORY) |
-            (1 << VIR_CGROUP_CONTROLLER_BLKIO);
+            (1 << VIR_CGROUP_CONTROLLER_BLKIO) |
+            (1 << VIR_CGROUP_CONTROLLER_CPUSET);
     }
     for (i = 0 ; i < VIR_CGROUP_CONTROLLER_LAST ; i++) {
         if (driver->cgroupControllers & (1 << i)) {