When wen mount any cgroup without "-o devices", we will fail to start vms: # virsh start vm1 error: Failed to start domain vm1 error: Unable to deny all devices for vm1: No such file or directory When wen mount any cgroup without "-o cpu", we will fail to get schedinfo: # virsh schedinfo vm1 Scheduler : posix error: unable to get cpu shares tunable: No such file or directory We should only use the cgroup controllers which are mounted on host. So I add virCgroupMounted() for qemuCgroupControllerActive() Signed-off-by: Lai Jiangshan <laijs(a)cn.fujitsu.com&gt; --- diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 3b127d6..5885ad8 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -61,6 +61,7 @@ virConfWriteMem; # cgroup.h virCgroupForDomain; virCgroupForDriver; +virCgroupMounted; virCgroupRemove; virCgroupFree; virCgroupAddTask; diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 16f34f7..f09d029 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -724,6 +724,8 @@ static int qemuCgroupControllerActive(struct qemud_driver *driver, { if (driver->cgroup == NULL) return 0; + if (!virCgroupMounted(driver->cgroup, controller)) + return 0; if (driver->cgroupControllers & (1 << controller)) return 1; return 0; diff --git a/src/util/cgroup.c b/src/util/cgroup.c index 7e887dc..8fac389 100644 --- a/src/util/cgroup.c +++ b/src/util/cgroup.c @@ -71,6 +71,17 @@ void virCgroupFree(virCgroupPtr *group) VIR_FREE(*group); } +/** + * virCgroupMounted: query whether a cgroup subsystem is mounted or not + * + * @cgroup: The group structure to be queried + * @controller: cgroup subsystem id + */ +bool virCgroupMounted(virCgroupPtr cgroup, int controller) +{ + return !!cgroup->controllers[controller].mountPoint; +} + #if defined HAVE_MNTENT_H && defined HAVE_GETMNTENT_R /* * Process /proc/mounts figuring out what controllers are diff --git a/src/util/cgroup.h b/src/util/cgroup.h index b8f2d08..9e1c61f 100644 --- a/src/util/cgroup.h +++ b/src/util/cgroup.h @@ -83,5 +83,6 @@ int virCgroupGetFreezerState(virCgroupPtr group, char **state); int virCgroupRemove(virCgroupPtr group); void virCgroupFree(virCgroupPtr *group); +bool virCgroupMounted(virCgroupPtr cgroup, int controller); #endif /* CGROUP_H */