linux.git/drivers/hv, branch v4.14.124

Drivers: hv: vmbus: Remove the undesired put_cpu_ptr() in hv_synic_cleanup()

2019-05-10T15:53:08+00:00

commit a0033bd1eae4650b69be07c17cb87393da584563 upstream.

With CONFIG_DEBUG_PREEMPT=y, the put_cpu_ptr() triggers an underflow
warning in preempt_count_sub().

Fixes: 37cdd991fac8 ("vmbus: put related per-cpu variable together")
Cc: stable@vger.kernel.org
Cc: Stephen Hemminger 
Signed-off-by: Dexuan Cui 
Reviewed-by: Michael Kelley 
Signed-off-by: Sasha Levin (Microsoft) 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Check for ring when getting debug info

2019-01-31T07:13:44+00:00

commit ba50bf1ce9a51fc97db58b96d01306aa70bc3979 upstream.

fc96df16a1ce is good and can already fix the "return stack garbage" issue,
but let's also improve hv_ringbuffer_get_debuginfo(), which would silently
return stack garbage, if people forget to check channel->state or
ring_info->ring_buffer, when using the function in the future.

Having an error check in the function would eliminate the potential risk.

Add a Fixes tag to indicate the patch depdendency.

Fixes: fc96df16a1ce ("Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels")
Cc: stable@vger.kernel.org
Cc: K. Y. Srinivasan 
Cc: Haiyang Zhang 
Signed-off-by: Stephen Hemminger 
Signed-off-by: Dexuan Cui 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

hv_balloon: avoid touching uninitialized struct page during tail onlining

2019-01-31T07:13:44+00:00

commit da8ced360ca8ad72d8f41f5c8fcd5b0e63e1555f upstream.

Hyper-V memory hotplug protocol has 2M granularity and in Linux x86 we use
128M. To deal with it we implement partial section onlining by registering
custom page onlining callback (hv_online_page()). Later, when more memory
arrives we try to online the 'tail' (see hv_bring_pgs_online()).

It was found that in some cases this 'tail' onlining causes issues:

 BUG: Bad page state in process kworker/0:2  pfn:109e3a
 page:ffffe08344278e80 count:0 mapcount:1 mapping:0000000000000000 index:0x0
 flags: 0xfffff80000000()
 raw: 000fffff80000000 dead000000000100 dead000000000200 0000000000000000
 raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
 page dumped because: nonzero mapcount
 ...
 Workqueue: events hot_add_req [hv_balloon]
 Call Trace:
  dump_stack+0x5c/0x80
  bad_page.cold.112+0x7f/0xb2
  free_pcppages_bulk+0x4b8/0x690
  free_unref_page+0x54/0x70
  hv_page_online_one+0x5c/0x80 [hv_balloon]
  hot_add_req.cold.24+0x182/0x835 [hv_balloon]
  ...

Turns out that we now have deferred struct page initialization for memory
hotplug so e.g. memory_block_action() in drivers/base/memory.c does
pages_correctly_probed() check and in that check it avoids inspecting
struct pages and checks sections instead. But in Hyper-V balloon driver we
do PageReserved(pfn_to_page()) check and this is now wrong.

Switch to checking online_section_nr() instead.

Signed-off-by: Vitaly Kuznetsov 
Cc: stable@kernel.org
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

x86, hyperv: remove PCI dependency

2019-01-13T09:00:59+00:00

[ Upstream commit c629421a990033ba539eb8585e73a2e6fa9ea631 ]

Need to be able to boot without PCI devices present.

Signed-off-by: Sinan Kaya 
Signed-off-by: Sasha Levin

Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels

2018-12-29T12:39:10+00:00

commit fc96df16a1ce80cbb3c316ab7d4dc8cd5c2852ce upstream.

Before 98f4c651762c, we returned zeros for unopened channels.
With 98f4c651762c, we started to return random on-stack values.

We'd better return -EINVAL instead.

Fixes: 98f4c651762c ("hv: move ringbuffer bus attributes to dev_groups")
Cc: stable@vger.kernel.org
Cc: K. Y. Srinivasan 
Cc: Haiyang Zhang 
Cc: Stephen Hemminger 
Signed-off-by: Dexuan Cui 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Offload the handling of channels to two workqueues

2018-12-13T08:18:53+00:00

commit 37c2578c0c40e286bc0d30bdc05290b2058cf66e upstream.

vmbus_process_offer() mustn't call channel->sc_creation_callback()
directly for sub-channels, because sc_creation_callback() ->
vmbus_open() may never get the host's response to the
OPEN_CHANNEL message (the host may rescind a channel at any time,
e.g. in the case of hot removing a NIC), and vmbus_onoffer_rescind()
may not wake up the vmbus_open() as it's blocked due to a non-zero
vmbus_connection.offer_in_progress, and finally we have a deadlock.

The above is also true for primary channels, if the related device
drivers use sync probing mode by default.

And, usually the handling of primary channels and sub-channels can
depend on each other, so we should offload them to different
workqueues to avoid possible deadlock, e.g. in sync-probing mode,
NIC1's netvsc_subchan_work() can race with NIC2's netvsc_probe() ->
rtnl_lock(), and causes deadlock: the former gets the rtnl_lock
and waits for all the sub-channels to appear, but the latter
can't get the rtnl_lock and this blocks the handling of sub-channels.

The patch can fix the multiple-NIC deadlock described above for
v3.x kernels (e.g. RHEL 7.x) which don't support async-probing
of devices, and v4.4, v4.9, v4.14 and v4.18 which support async-probing
but don't enable async-probing for Hyper-V drivers (yet).

The patch can also fix the hang issue in sub-channel's handling described
above for all versions of kernels, including v4.19 and v4.20-rc4.

So actually the patch should be applied to all the existing kernels,
not only the kernels that have 8195b1396ec8.

Fixes: 8195b1396ec8 ("hv_netvsc: fix deadlock on hotplug")
Cc: stable@vger.kernel.org
Cc: Stephen Hemminger 
Cc: K. Y. Srinivasan 
Cc: Haiyang Zhang 
Signed-off-by: Dexuan Cui 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: check the creation_status in vmbus_establish_gpadl()

2018-12-05T18:41:26+00:00

commit eceb05965489784f24bbf4d61ba60e475a983016 upstream.

This is a longstanding issue: if the vmbus upper-layer drivers try to
consume too many GPADLs, the host may return with an error
0xC0000044 (STATUS_QUOTA_EXCEEDED), but currently we forget to check
the creation_status, and hence we can pass an invalid GPADL handle
into the OPEN_CHANNEL message, and get an error code 0xc0000225 in
open_info->response.open_result.status, and finally we hang in
vmbus_open() -> "goto error_free_info" -> vmbus_teardown_gpadl().

With this patch, we can exit gracefully on STATUS_QUOTA_EXCEEDED.

Cc: Stephen Hemminger 
Cc: K. Y. Srinivasan 
Cc: Haiyang Zhang 
Cc: stable@vger.kernel.org
Signed-off-by: Dexuan Cui 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Use cpumask_var_t for on-stack cpu mask

2018-11-13T19:14:58+00:00

[ Upstream commit 25355252607ca288f329ee033f387764883393f6 ]

A cpumask structure on the stack can cause a warning with
CONFIG_NR_CPUS=8192 (e.g. Ubuntu 16.04 and 18.04 use this):

drivers/hv//channel_mgmt.c: In function ‘init_vp_index’:
drivers/hv//channel_mgmt.c:702:1: warning: the frame size of 1032 bytes
  is larger than 1024 bytes [-Wframe-larger-than=]

Nowadays it looks most distros enable CONFIG_CPUMASK_OFFSTACK=y, and
hence we can work around the warning by using cpumask_var_t.

Signed-off-by: Dexuan Cui 
Cc: K. Y. Srinivasan 
Cc: Haiyang Zhang 
Cc: Stephen Hemminger 
Cc: 
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: Use get/put_cpu() in vmbus_connect()

2018-10-10T06:54:28+00:00

commit 41e270f6898e7502be9fd6920ee0a108ca259d36 upstream.

With CONFIG_DEBUG_PREEMPT=y, I always see this warning:
BUG: using smp_processor_id() in preemptible [00000000]

Fix the false warning by using get/put_cpu().

Here vmbus_connect() sends a message to the host and waits for the
host's response. The host will deliver the response message and an
interrupt on CPU msg->target_vcpu, and later the interrupt handler
will wake up vmbus_connect(). vmbus_connect() doesn't really have
to run on the same cpu as CPU msg->target_vcpu, so it's safe to
call put_cpu() just here.

Signed-off-by: Dexuan Cui 
Cc: stable@vger.kernel.org
Cc: K. Y. Srinivasan 
Cc: Haiyang Zhang 
Cc: Stephen Hemminger 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Cleanup synic memory free path

2018-09-19T20:43:40+00:00

[ Upstream commit 572086325ce9a9e348b8748e830653f3959e88b6 ]

clk_evt memory is not being freed when the synic is shutdown
or when there is an allocation error.  Add the appropriate
kfree() call, along with a comment to clarify how the memory
gets freed after an allocation error.  Make the free path
consistent by removing checks for NULL since kfree() and
free_page() already do the check.

Signed-off-by: Michael Kelley 
Reported-by: Dan Carpenter 
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman