On Mon, Jan 12, 2015 at 05:50:11PM +0100, Vitaly Kuznetsov wrote: > When an SMP Hyper-V guest is running on top of 2012R2 Server and secondary > cpus are sent offline (with echo 0 > /sys/devices/system/cpu/cpu$cpu/online) > the system freeze is observed. This happens due to the fact that on newer > hypervisors (Win8, WS2012R2, ...) vmbus channel handlers are distributed > across all cpus (see init_vp_index() function in drivers/hv/channel_mgmt.c) > and on cpu offlining nobody reassigns them to CPU0. Prevent cpu offlining > when vmbus is loaded until the issue is fixed host-side. > > This patch also disables hibernation but it is OK as it is also broken (MCE > error is hit on resume). Suspend still works. > > Tested with WS2008R2 and WS2012R2. > > Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> > Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> > --- > Changes since v2: > - repair the build when vmbus is builded as a module [Greg KH] by saving > current cpu_disable pointer to previous_cpu_disable and restoring it on > unload; > - return -ENOSYS (same as native_cpu_disable when !CONFIG_HOTPLUG_CPU) instead > of -1 in hyperv_cpu_disable(). > > Changes since v1: > - introduce hv_cpu_hotplug_quirk() function to not spread #ifdefs [Greg KH]; > - add pr_notice() message "hv_vmbus: CPU offlining is not supported by > hypervisor". > --- > drivers/hv/vmbus_drv.c | 36 ++++++++++++++++++++++++++++++++++++ > 1 file changed, 36 insertions(+) Doesn't apply to my char-misc-test branch at all :( _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
