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  1. 05 6月, 2019 2 次提交
  3. 13 4月, 2019 1 次提交
  5. 11 4月, 2019 3 次提交
    • K
      Drivers: hv: vmbus: Fix race condition with new ring_buffer_info mutex · 14948e39
      由 Kimberly Brown 提交于 
      Fix a race condition that can result in a ring buffer pointer being set
to null while a "_show" function is reading the ring buffer's data. This
problem was discussed here: https://lkml.org/lkml/2018/10/18/779

To fix the race condition, add a new mutex lock to the
"hv_ring_buffer_info" struct. Add a new function,
"hv_ringbuffer_pre_init()", where a channel's inbound and outbound
ring_buffer_info mutex locks are initialized.

Acquire/release the locks in the "hv_ringbuffer_cleanup()" function,
which is where the ring buffer pointers are set to null.

Acquire/release the locks in the four channel-level "_show" functions
that access ring buffer data. Remove the "const" qualifier from the
"vmbus_channel" parameter and the "rbi" variable of the channel-level
"_show" functions so that the locks can be acquired/released in these
functions.

Acquire/release the locks in hv_ringbuffer_get_debuginfo(). Remove the
"const" qualifier from the "hv_ring_buffer_info" parameter so that the
locks can be acquired/released in this function.
Signed-off-by: NKimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      14948e39
    • K
      Drivers: hv: vmbus: Set ring_info field to 0 and remove memset · 4713eb7b
      由 Kimberly Brown 提交于 
      Set "ring_info->priv_read_index" to 0. Now, all of ring_info's fields
are explicitly set in this function. The memset() call is no longer
necessary, so remove it.
Signed-off-by: NKimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      4713eb7b
    • K
      Drivers: hv: vmbus: Refactor chan->state if statement · fcedbb29
      由 Kimberly Brown 提交于 
      The chan->state "if statement" was introduced in commit 6712cc9c
("vmbus: don't return values for uninitalized channels"). That commit
states that the purpose of the chan->state "if statement" is to prevent
returning garbage or causing a kernel OOPS when the channel ring buffer
is not initialized. The changes in this patch provide the same
protection.

Refactor the chan->state “if statement” in vmbus_chan_attr_show():
 - Instead of checking the channel state in the "if statement", check
   whether the channel ring buffer pointer is NULL. Checking the
   ring buffer pointer makes this code consistent with
   hv_ringbuffer_get_debuginfo().

 - Move the "if statement" to the four "_show" functions that access a
   channel ring buffer. Only four of the channel-level "_show" functions
   access a ring buffer. The ring buffer pointer does not need to be
   checked before calling the other "_show" functions, and moving the
   ring buffer pointer "if statement" to the "_show" functions that
   access a ring buffer makes the purpose of the "if statement" clear.
Signed-off-by: NKimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      fcedbb29
  7. 21 3月, 2019 1 次提交
    • K
      Drivers: hv: vmbus: Expose monitor data only when monitor pages are used · 46fc1548
      由 Kimberly Brown 提交于 
      There are two methods for signaling the host: the monitor page mechanism
and hypercalls. The monitor page mechanism is used by performance
critical channels (storage, networking, etc.) because it provides
improved throughput. However, latency is increased. Monitor pages are
allocated to these channels.

Monitor pages are not allocated to channels that do not use the monitor
page mechanism. Therefore, these channels do not have a valid monitor id
or valid monitor page data. In these cases, some of the "_show"
functions return incorrect data. They return an invalid monitor id and
data that is beyond the bounds of the hv_monitor_page array fields.

The "channel->offermsg.monitor_allocated" value can be used to determine
whether monitor pages have been allocated to a channel.

Add "is_visible()" callback functions for the device-level and
channel-level attribute groups. These functions will hide the monitor
sysfs files when the monitor mechanism is not used.

Remove ".default_attributes" from "vmbus_chan_attrs" and create a
channel-level attribute group. These changes allow the new
"is_visible()" callback function to be applied to the channel-level
attributes.

Call "sysfs_create_group()" in "vmbus_add_channel_kobj()" to create the
channel's sysfs files. Add a new function,
“vmbus_remove_channel_attr_group()”, and call it in "free_channel()" to
remove the channel's sysfs files when the channel is closed.
Signed-off-by: NKimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      46fc1548
  9. 06 3月, 2019 2 次提交
  11. 23 2月, 2019 1 次提交
  13. 15 2月, 2019 2 次提交
    • K
      Drivers: hv: vmbus: Expose counters for interrupts and full conditions · 396ae57e
      由 Kimberly Brown 提交于 
      Counter values for per-channel interrupts and ring buffer full
conditions are useful for investigating performance.

Expose counters in sysfs for 2 types of guest to host interrupts:
1) Interrupts caused by the channel's outbound ring buffer transitioning
from empty to not empty
2) Interrupts caused by the channel's inbound ring buffer transitioning
from full to not full while a packet is waiting for enough buffer space to
become available

Expose 2 counters in sysfs for the number of times that write operations
encountered a full outbound ring buffer:
1) The total number of write operations that encountered a full
condition
2) The number of write operations that were the first to encounter a
full condition

Increment the outbound full condition counters in the
hv_ringbuffer_write() function because, for most drivers, a full
outbound ring buffer is detected in that function. Also increment the
outbound full condition counters in the set_channel_pending_send_size()
function. In the hv_sock driver, a full outbound ring buffer is detected
and set_channel_pending_send_size() is called before
hv_ringbuffer_write() is called.

I tested this patch by confirming that the sysfs files were created and
observing the counter values. The values seemed to increase by a
reasonable amount when the Hyper-v related drivers were in use.
Signed-off-by: NKimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      396ae57e
    • A
      vmbus: Switch to use new generic UUID API · 593db803
      由 Andy Shevchenko 提交于 
      There are new types and helpers that are supposed to be used in new code.

As a preparation to get rid of legacy types and API functions do
the conversion here.

Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: devel@linuxdriverproject.org
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NMichael Kelley <mikelley@microsoft.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      593db803
  15. 10 1月, 2019 3 次提交
    • D
      vmbus: fix subchannel removal · b5679ceb
      由 Dexuan Cui 提交于 
      The changes to split ring allocation from open/close, broke
the cleanup of subchannels. This resulted in problems using
uio on network devices because the subchannel was left behind
when the network device was unbound.

The cause was in the disconnect logic which used list splice
to move the subchannel list into a local variable. This won't
work because the subchannel list is needed later during the
process of the rescind messages (relid2channel).

The fix is to just leave the subchannel list in place
which is what the original code did. The list is cleaned
up later when the host rescind is processed.

Without the fix, we have a lot of "hang" issues in netvsc when we
try to change the NIC's MTU, set the number of channels, etc.

Fixes: ae6935ed ("vmbus: split ring buffer allocation from open")
Cc: stable@vger.kernel.org
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDexuan Cui <decui@microsoft.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      b5679ceb
    • V
      hv_balloon: avoid touching uninitialized struct page during tail onlining · da8ced36
      由 Vitaly Kuznetsov 提交于 
      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: NVitaly Kuznetsov <vkuznets@redhat.com>
Cc: stable@kernel.org
Signed-off-by: NSasha Levin <sashal@kernel.org>
      da8ced36
    • D
      Drivers: hv: vmbus: Check for ring when getting debug info · ba50bf1c
      由 Dexuan Cui 提交于 
      fc96df16 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: fc96df16 ("Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels")
Cc: stable@vger.kernel.org
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDexuan Cui <decui@microsoft.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      ba50bf1c
  17. 29 12月, 2018 2 次提交
  19. 15 12月, 2018 1 次提交
  21. 14 12月, 2018 2 次提交
  23. 03 12月, 2018 1 次提交
    • D
      Drivers: hv: vmbus: Offload the handling of channels to two workqueues · 37c2578c
      由 Dexuan Cui 提交于 
      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 8195b139.

Fixes: 8195b139 ("hv_netvsc: fix deadlock on hotplug")
Cc: stable@vger.kernel.org
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDexuan Cui <decui@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      37c2578c
  25. 27 11月, 2018 2 次提交
  27. 12 11月, 2018 4 次提交
  29. 16 10月, 2018 1 次提交
  31. 03 10月, 2018 4 次提交
  33. 30 9月, 2018 1 次提交
    • D
      Drivers: hv: vmbus: Use get/put_cpu() in vmbus_connect() · 41e270f6
      由 Dexuan Cui 提交于 
      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: NDexuan Cui <decui@microsoft.com>
Cc: stable@vger.kernel.org
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      41e270f6
  35. 26 9月, 2018 3 次提交
  37. 12 9月, 2018 3 次提交
  39. 02 8月, 2018 1 次提交