Hey Linus, Please pull this branch, which has one fix: git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/for-linus-fixes-3.3 which is a fix to Kay Sievers global "convert sysdev_class -> device/subsystem" patchset which inadvertly missed the proper subsystem in the balloon code. The negative effect of his patch is that the xen tool stack can't now properly balloon the memory hence we can't launch the guests. The patch is based on 070680218379e15c1901f4bf21b98e3cbf12b527, which was the "xen-balloon: convert sysdev_class to a regular subsystem" Konrad Rzeszutek Wilk (1): xen/balloon: Move the registration from device to subsystem. drivers/xen/xen-balloon.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) And the bug-fix: Thanks!! diff --git a/drivers/xen/xen-balloon.c b/drivers/xen/xen-balloon.c index 3832e30..596e6a7 100644 --- a/drivers/xen/xen-balloon.c +++ b/drivers/xen/xen-balloon.c @@ -221,7 +221,7 @@ static int register_balloon(struct device *dev) { int i, error; - error = bus_register(&balloon_subsys); + error = subsys_system_register(&balloon_subsys, NULL); if (error) return error;