linux-stable.git/drivers/hv, branch v4.9.13

Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()

2017-02-14T23:25:39+00:00

commit 433e19cf33d34bb6751c874a9c00980552fe508c upstream.

Commit a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in
hv_need_to_signal_on_read()")
added the proper mb(), but removed the test "prev_write_sz < pending_sz"
when making the signal decision.

As a result, the guest can signal the host unnecessarily,
and then the host can throttle the guest because the host
thinks the guest is buggy or malicious; finally the user
running stress test can perceive intermittent freeze of
the guest.

This patch brings back the test, and properly handles the
in-place consumption APIs used by NetVSC (see get_next_pkt_raw(),
put_pkt_raw() and commit_rd_index()).

Fixes: a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in
hv_need_to_signal_on_read()")

Signed-off-by: Dexuan Cui 
Reported-by: Rolf Neugebauer 
Tested-by: Rolf Neugebauer 
Cc: "K. Y. Srinivasan" 
Cc: Haiyang Zhang 
Cc: Stephen Hemminger 
Signed-off-by: K. Y. Srinivasan 
Cc: Rolf Neugebauer 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: On the read path cleanup the logic to interrupt the host

2017-02-14T23:25:38+00:00

commit 3372592a140db69fd63837e81f048ab4abf8111e upstream.

Signal the host when we determine the host is to be signaled -
on th read path. The currrent code determines the need to signal in the
ringbuffer code and actually issues the signal elsewhere. This can result
in the host viewing this interrupt as spurious since the host may also
poll the channel. Make the necessary adjustments.

Signed-off-by: K. Y. Srinivasan 
Cc: Rolf Neugebauer 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: On write cleanup the logic to interrupt the host

2017-02-14T23:25:38+00:00

commit 1f6ee4e7d83586c8b10bd4f2f4346353d04ce884 upstream.

Signal the host when we determine the host is to be signaled.
The currrent code determines the need to signal in the ringbuffer
code and actually issues the signal elsewhere. This can result
in the host viewing this interrupt as spurious since the host may also
poll the channel. Make the necessary adjustments.

Signed-off-by: K. Y. Srinivasan 
Cc: Rolf Neugebauer 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Base host signaling strictly on the ring state

2017-02-14T23:25:38+00:00

commit 74198eb4a42c4a3c4fbef08fa01a291a282f7c2e upstream.

One of the factors that can result in the host concluding that a given
guest in mounting a DOS attack is if the guest generates interrupts
to the host when the host is not expecting it. If these "spurious"
interrupts reach a certain rate, the host can throttle the guest to
minimize the impact. The host computation of the "expected number
of interrupts" is strictly based on the ring transitions. Until
the host logic is fixed, base the guest logic to interrupt solely
on the ring state.

Signed-off-by: K. Y. Srinivasan 
Cc: Rolf Neugebauer 
Signed-off-by: Greg Kroah-Hartman

hv: acquire vmbus_connection.channel_mutex in vmbus_free_channels()

2017-01-09T07:32:18+00:00

commit abd1026da4a7700a8db370947f75cd17b6ae6f76 upstream.

"kernel BUG at drivers/hv/channel_mgmt.c:350!" is observed when hv_vmbus
module is unloaded. BUG_ON() was introduced in commit 85d9aa705184
("Drivers: hv: vmbus: add an API vmbus_hvsock_device_unregister()") as
vmbus_free_channels() codepath was apparently forgotten.

Fixes: 85d9aa705184 ("Drivers: hv: vmbus: add an API vmbus_hvsock_device_unregister()")

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

vmbus: make sysfs names consistent with PCI

2016-11-01T15:07:13+00:00

In commit 9a56e5d6a0ba ("Drivers: hv: make VMBus bus ids persistent")
the name of vmbus devices in sysfs changed to be (in 4.9-rc1):
  /sys/bus/vmbus/vmbus-6aebe374-9ba0-11e6-933c-00259086b36b

The prefix ("vmbus-") is redundant and differs from how PCI is
represented in sysfs. Therefore simplify to:
  /sys/bus/vmbus/6aebe374-9ba0-11e6-933c-00259086b36b

Please merge this before 4.9 is released and the old format
has to live forever.

Signed-off-by: Stephen Hemminger 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

hv: do not lose pending heartbeat vmbus packets

2016-10-25T06:52:10+00:00

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 
CC: Stable 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: get rid of id in struct vmbus_channel

2016-09-27T10:35:49+00:00

The auto incremented counter is not being used anymore, get rid of it.

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

Drivers: hv: make VMBus bus ids persistent

2016-09-27T10:35:49+00:00

Some tools use bus ids to identify devices and they count on the fact
that these ids are persistent across reboot. This may be not true for
VMBus as we use auto incremented counter from alloc_channel() as such
id. Switch to using if_instance from channel offer, this id is supposed
to be persistent.

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

Drivers: hv: hv_util: Avoid dynamic allocation in time synch

2016-09-09T11:48:23+00:00

Under stress, we have seen allocation failure in time synch code. Avoid
this dynamic allocation.

Signed-off-by: Vivek Yadav 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman