android_kernel_samsung_msm8976/drivers/hv
Vitaly Kuznetsov 70415182b6 Drivers: hv: vmbus: prevent cpu offlining on newer hypervisors
commit e513229b4c386e6c9f66298c13fde92f73e6e1ac upstream.

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@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
[ 3chas3@gmail.com: rebase to 3.14-stable ]
Signed-off-by: Chas Williams <3chas3@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2016-06-07 10:42:52 +02:00
..
Kconfig
Makefile
channel.c
channel_mgmt.c
connection.c
hv.c
hv_balloon.c
hv_kvp.c
hv_snapshot.c
hv_util.c
hyperv_vmbus.h
ring_buffer.c
vmbus_drv.c Drivers: hv: vmbus: prevent cpu offlining on newer hypervisors 2016-06-07 10:42:52 +02:00