linux-toradex.git/drivers/hv, branch v4.4.38

hv: do not lose pending heartbeat vmbus packets

2016-11-10T15:36:34+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: Greg Kroah-Hartman

drivers:hv: Lock access to hyperv_mmio resource tree

2016-09-15T06:27:50+00:00

[ Upstream commit e16dad6bfe1437aaee565f875a6713ca7ce81bdf ]

In existing code, this tree of resources is created
in single-threaded code and never modified after it is
created, and thus needs no locking.  This patch introduces
a semaphore for tree access, as other patches in this
series introduce run-time modifications of this resource
tree which can happen on multiple threads.

Signed-off-by: Jake Oshins 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

Drivers: hv: vmbus: don't manipulate with clocksources on crash

2016-09-15T06:27:46+00:00

[ Upstream commit 3ccb4fd8f492f99aece21acc1bd6142275f26236 ]

clocksource_change_rating() involves mutex usage and can't be called
in interrupt context. It also makes sense to avoid doing redundant work
on crash.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: avoid scheduling in interrupt context in vmbus_initiate_unload()

2016-09-15T06:27:46+00:00

[ Upstream commit 415719160de3fae3bb9cbc617664649919cd00d0 ]

We have to call vmbus_initiate_unload() on crash to make kdump work but
the crash can also be happening in interrupt (e.g. Sysrq + c results in
such) where we can't schedule or the following will happen:

[  314.905786] bad: scheduling from the idle thread!

Just skipping the wait (and even adding some random wait here) won't help:
to make host-side magic working we're supposed to receive CHANNELMSG_UNLOAD
(and actually confirm the fact that we received it) but we can't use
interrupt-base path (vmbus_isr()-> vmbus_on_msg_dpc()). Implement a simple
busy wait ignoring all the other messages and use it if we're in an
interrupt context.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: avoid infinite loop in init_vp_index()

2016-09-15T06:27:45+00:00

[ Upstream commit 79fd8e706637a5c7c41f9498fe0fbfb437abfdc8 ]

When we pick a CPU to use for a new subchannel we try find a non-used one
on the appropriate NUMA node, we keep track of them with the
primary->alloced_cpus_in_node mask. Under normal circumstances we don't run
out of available CPUs but it is possible when we we don't initialize some
cpus in Linux, e.g. when we boot with 'nr_cpus=' limitation.

Avoid the infinite loop in init_vp_index() by checking that we still have
non-used CPUs in the alloced_cpus_in_node mask and resetting it in case
we don't.

Signed-off-by: Vitaly Kuznetsov 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: fix rescind-offer handling for device without a driver

2016-09-15T06:27:41+00:00

[ Upstream commit 34c6801e3310ad286c7bb42bc88d42926b8f99bf ]

In the path vmbus_onoffer_rescind() -> vmbus_device_unregister()  ->
device_unregister() -> ... -> __device_release_driver(), we can see for a
device without a driver loaded: dev->driver is NULL, so
dev->bus->remove(dev), namely vmbus_remove(), isn't invoked.

As a result, vmbus_remove() -> hv_process_channel_removal() isn't invoked
and some cleanups(like sending a CHANNELMSG_RELID_RELEASED message to the
host) aren't done.

We can demo the issue this way:
1. rmmod hv_utils;
2. disable the Heartbeat Integration Service in Hyper-V Manager and lsvmbus
shows the device disappears.
3. re-enable the Heartbeat in Hyper-V Manager and modprobe hv_utils, but
lsvmbus shows the device can't appear again.
This is because, the host thinks the VM hasn't released the relid, so can't
re-offer the device to the VM.

We can fix the issue by moving hv_process_channel_removal()
from vmbus_close_internal() to vmbus_device_release(), since the latter is
always invoked on device_unregister(), whether or not the dev has a driver
loaded.

Signed-off-by: Dexuan Cui 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: serialize process_chn_event() and vmbus_close_internal()

2016-09-15T06:27:40+00:00

[ Upstream commit 63d55b2aeb5e4faa170316fee73c3c47ea9268c7 ]

process_chn_event(), running in the tasklet, can race with
vmbus_close_internal() in the case of SMP guest, e.g., when the former is
accessing channel->inbound.ring_buffer, the latter could be freeing the
ring_buffer pages.

To resolve the race, we can serialize them by disabling the tasklet when
the latter is running here.

Signed-off-by: Dexuan Cui 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vss: run only on supported host versions

2016-09-15T06:27:40+00:00

[ Upstream commit ed9ba608e4851144af8c7061cbb19f751c73e998 ]

The Backup integration service on WS2012 has appearently trouble to
negotiate with a guest which does not support the provided util version.
Currently the VSS driver supports only version 5/0. A WS2012 offers only
version 1/x and 3/x, and vmbus_prep_negotiate_resp correctly returns an
empty icframe_vercnt/icmsg_vercnt. But the host ignores that and
continues to send ICMSGTYPE_NEGOTIATE messages. The result are weird
errors during boot and general misbehaviour.

Check the Windows version to work around the host bug, skip hv_vss_init
on WS2012 and older.

Signed-off-by: Olaf Hering 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

drivers/hv: cleanup synic msrs if vmbus connect failed

2016-09-15T06:27:40+00:00

[ Upstream commit 17efbee8ba02ef00d3b270998978f8a1a90f1d92 ]

Before vmbus_connect() synic is setup per vcpu - this means
hypervisor receives writes at synic msr's and probably allocate
hypervisor resources per synic setup.

If vmbus_connect() failed for some reason it's neccessary to cleanup
synic setup by call hv_synic_cleanup() at each vcpu to get a chance
to free allocated resources by hypervisor per synic.

This patch does appropriate cleanup in case of vmbus_connect() failure.

Signed-off-by: Andrey Smetanin 
Signed-off-by: Denis V. Lunev 
Reviewed-by: Vitaly Kuznetsov 
CC: "K. Y. Srinivasan" 
CC: Haiyang Zhang 
CC: Vitaly Kuznetsov 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: util: catch allocation errors

2016-09-15T06:27:40+00:00

[ Upstream commit cdc0c0c94e4e6dfa371d497a3130f83349b6ead6 ]

Catch allocation errors in hvutil_transport_send.

Fixes: 14b50f80c32d ('Drivers: hv: util: introduce hv_utils_transport abstraction')

Signed-off-by: Olaf Hering 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman