linux-stable.git/drivers/hv, branch v3.12.73

Drivers: hv: avoid vfree() on crash

2017-04-07T07:17:46+00:00

commit a9f61ca793becabdefab03b77568d6c6f8c1bc79 upstream.

When we crash from NMI context (e.g. after NMI injection from host when
'sysctl -w kernel.unknown_nmi_panic=1' is set) we hit

    kernel BUG at mm/vmalloc.c:1530!

as vfree() is denied. While the issue could be solved with in_nmi() check
instead I opted for skipping vfree on all sorts of crashes to reduce the
amount of work which can cause consequent crashes. We don't really need to
free anything on crash.

[js] no tsc and kexec in 3.12 yet

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: K. Y. Srinivasan 
Cc: Sumit Semwal 
Signed-off-by: Jiri Slaby

Drivers: hv: balloon: don't crash when memory is added in non-sorted order

2017-04-07T07:17:46+00:00

commit 77c0c9735bc0ba5898e637a3a20d6bcb50e3f67d upstream.

When we iterate through all HA regions in handle_pg_range() we have an
assumption that all these regions are sorted in the list and the
'start_pfn >= has->end_pfn' check is enough to find the proper region.
Unfortunately it's not the case with WS2016 where host can hot-add regions
in a different order. We end up modifying the wrong HA region and crashing
later on pages online. Modify the check to make sure we found the region
we were searching for while iterating. Fix the same check in pfn_covered()
as well.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: K. Y. Srinivasan 
Cc: Sumit Semwal 
Signed-off-by: Jiri Slaby

drivers: hv: Turn off write permission on the hypercall page

2017-03-13T20:40:52+00:00

commit 372b1e91343e657a7cc5e2e2bcecd5140ac28119 upstream.

The hypercall page only needs to be executable but currently it is setup to
be writable as well. Fix the issue.

Signed-off-by: K. Y. Srinivasan 
Acked-by: Kees Cook 
Reported-by: Stephen Hemminger 
Tested-by: Stephen Hemminger 
Signed-off-by: Jiri Slaby

hv: allocate synic pages for all present CPUs

2017-03-13T20:40:34+00:00

commit 421b8f20d3c381b215f988b42428f56fc3b82405 upstream.

It may happen that not all CPUs are online when we do hv_synic_alloc() and
in case more CPUs come online later we may try accessing these allocated
structures.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Jiri Slaby

hv: do not lose pending heartbeat vmbus packets

2016-11-24T15:23:22+00:00

commit 407a3aee6ee2d2cb46d9ba3fc380bc29f35d020c upstream.

The host keeps sending heartbeat packets independent of the
guest responding to them.  Even though we respond to the heartbeat messages at
interrupt level, we can have situations where there maybe multiple heartbeat
messages pending that have not been responded to. For instance this occurs when the
VM is paused and the host continues to send the heartbeat messages.
Address this issue by draining and responding to all
the heartbeat messages that maybe pending.

Signed-off-by: Long Li 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Jiri Slaby

Drivers: hv: vmbus: prevent cpu offlining on newer hypervisors

2016-05-03T05:45:09+00:00

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 
Signed-off-by: K. Y. Srinivasan 
[ 3chas3@gmail.com: rebase to 3.14-stable ]
Signed-off-by: Chas Williams <3chas3@gmail.com>
Signed-off-by: Jiri Slaby

Drivers: hv: vmbus: Don't wait after requesting offers

2015-05-15T07:10:55+00:00

commit 73cffdb65e679b98893f484063462c045adcf212 upstream.

Don't wait after sending request for offers to the host. This wait is
unnecessary and simply adds 5 seconds to the boot time.

Signed-off-by: K. Y. Srinivasan 
Cc: 
Signed-off-by: Jiri Slaby

Drivers: hv: vmbus: Fix a bug in the error path in vmbus_open()

2015-05-15T07:10:31+00:00

commit 40384e4bbeb9f2651fe9bffc0062d9f31ef625bf upstream.

Correctly rollback state if the failure occurs after we have handed over
the ownership of the buffer to the host.

Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Jiri Slaby

Drivers: hv: vmbus: Fix a race condition when unregistering a device

2015-01-26T13:39:01+00:00

commit 04a258c162a85c0f4ae56be67634dc43c9a4fa9b upstream.

When build with Debug the following crash is sometimes observed:
Call Trace:
 [] string+0x40/0x100
 [] vsnprintf+0x218/0x5e0
 [] ? trace_hardirqs_off+0xd/0x10
 [] vscnprintf+0x11/0x30
 [] vprintk+0xd0/0x5c0
 [] ? vmbus_process_rescind_offer+0x0/0x110 [hv_vmbus]
 [] printk+0x41/0x45
 [] vmbus_device_unregister+0x2c/0x40 [hv_vmbus]
 [] vmbus_process_rescind_offer+0x2b/0x110 [hv_vmbus]
...

This happens due to the following race: between 'if (channel->device_obj)' check
in vmbus_process_rescind_offer() and pr_debug() in vmbus_device_unregister() the
device can disappear. Fix the issue by taking an additional reference to the
device before proceeding to vmbus_device_unregister().

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Jiri Slaby

Drivers: hv: vmbus: Fix a bug in vmbus_open()

2014-10-31T14:11:15+00:00

commit 45d727cee9e200f5b351528b9fb063b69cf702c8 upstream.

Fix a bug in vmbus_open() and properly propagate the error. I would
like to thank Dexuan Cui  for identifying the
issue.

Signed-off-by: K. Y. Srinivasan 
Tested-by: Sitsofe Wheeler 
Signed-off-by: Jiri Slaby