linux-toradex.git/include/linux/hyperv.h, branch v5.1-rc1

Drivers: hv: vmbus: Expose counters for interrupts and full conditions

2019-02-15T01:56:10+00:00

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: Kimberly Brown 
Reviewed-by:  Michael Kelley 
Signed-off-by: Sasha Levin

vmbus: Switch to use new generic UUID API

2019-02-15T01:45:23+00:00

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" 
Cc: Haiyang Zhang 
Cc: Stephen Hemminger 
Cc: devel@linuxdriverproject.org
Signed-off-by: Andy Shevchenko 
Reviewed-by:  Michael Kelley 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Sasha Levin

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

2019-01-09T19:20:47+00:00

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

Merge 4.20-rc6 into char-misc-next

2018-12-10T08:22:34+00:00

This should resolve the hv driver merge conflict.

Signed-off-by: Greg Kroah-Hartman

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

2018-12-03T07:01:01+00:00

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: Remove the useless API vmbus_get_outgoing_channel()

2018-11-26T19:21:21+00:00

Commit d86adf482b84 ("scsi: storvsc: Enable multi-queue support") removed
the usage of the API in Jan 2017, and the API is not used since then.

netvsc and storvsc have their own algorithms to determine the outgoing
channel, so this API is useless.

And the API is potentially unsafe, because it reads primary->num_sc without
any lock held. This can be risky considering the RESCIND-OFFER message.

Let's remove the API.

Cc: Long Li 
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

vmbus: split ring buffer allocation from open

2018-09-25T18:33:24+00:00

The UIO driver needs the ring buffer to be persistent(reused)
across open/close. Split the allocation and setup of ring buffer
out of vmbus_open. For normal usage vmbus_open/vmbus_close there
are no changes; only impacts uio_hv_generic which needs to keep
ring buffer memory and reuse when application restarts.

Signed-off-by: Stephen Hemminger 
Signed-off-by: Greg Kroah-Hartman

vmbus: keep pointer to ring buffer page

2018-09-25T18:33:24+00:00

Avoid going from struct page to virt address (and back) by just
keeping pointer to the allocated pages instead of virt address.

Signed-off-by: Stephen Hemminger 
Signed-off-by: Greg Kroah-Hartman

vmbus: pass channel to hv_process_channel_removal

2018-09-25T18:33:24+00:00

Rather than passing relid and then looking up the channel.
Pass the channel directly, since caller already knows it.

Signed-off-by: Stephen Hemminger 
Signed-off-by: Greg Kroah-Hartman

vmbus: add driver_override support

2018-09-12T07:46:46+00:00

Add support for overriding the default driver for a VMBus device
in the same way that it can be done for PCI devices. This patch
adds the /sys/bus/vmbus/devices/.../driver_override file
and the logic for matching.

This is used by driverctl tool to do driver override.
https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitlab.com%2Fdriverctl%2Fdriverctl&data=02%7C01%7Ckys%40microsoft.com%7C42e803feb2c544ef6ea908d5fd538878%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636693457619960040&sdata=kEyYHRIjNZCk%2B37moCSqbrZL426YccNQrsWpENcrZdw%3D&reserved=0

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