linux-toradex.git/Documentation/ABI/stable/sysfs-bus-vmbus, branch master

docs: typo fixes in Documentation/ABI/

2021-05-13T15:13:25+00:00

Fix the following typos in the Documentation/ABI/ directory:

- In file obsolete/sysfs-cpuidle, change "obselete" for "obsolete".

- In file removed/sysfs-kernel-uids, change "propotional" for "proportional".

- In directory stable/, fix the following words: "associtated" for "associated",
  "hexidecimal" for "hexadecimal", "vlue" for "value", "csed" for "caused" and
  "wrtie" for "write". This updates a total of five files.

- In directory testing/, fix the following words: "subystem" for "subsystem",
  "isochrnous" for "isochronous", "Desctiptors" for "Descriptors", "picutre" for
  "picture", "capture" for "capture", "occured" for "ocurred", "connnected" for
  "connected","agressively" for "aggressively","manufacturee" for "manufacturer"
  and "transaction" for "transaction", "malformatted" for "incorrectly formated"
  ,"internel" for "internal", "writtento" for "written to", "specificed" for
  "specified", "beyound" for "beyond", "Symetric" for "Symmetric". This updates
  a total of eleven files.

Signed-off-by: Carlos Bilbao 
Reviewed-by: Randy Dunlap 
Reviewed-by: Mauro Carvalho Chehab 
Link: https://lore.kernel.org/r/5710038.lOV4Wx5bFT@iron-maiden
Signed-off-by: Jonathan Corbet

Drivers: hv: vmbus: Add /sys/bus/vmbus/hibernation

2021-02-11T08:47:05+00:00

When a Linux VM runs on Hyper-V, if the host toolstack doesn't support
hibernation for the VM (this happens on old Hyper-V hosts like Windows
Server 2016, or new Hyper-V hosts if the admin or user doesn't declare
the hibernation intent for the VM), the VM is discouraged from trying
hibernation (because the host doesn't guarantee that the VM's virtual
hardware configuration will remain exactly the same across hibernation),
i.e. the VM should not try to set up the swap partition/file for
hibernation, etc.

x86 Hyper-V uses the presence of the virtual ACPI S4 state as the
indication of the host toolstack support for a VM. Currently there is
no easy and reliable way for the userspace to detect the presence of
the state (see https://lkml.org/lkml/2020/12/11/1097).  Add
/sys/bus/vmbus/hibernation for this purpose.

Signed-off-by: Dexuan Cui 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/20210107014552.14234-1-decui@microsoft.com
Signed-off-by: Wei Liu

docs: ABI: stable: remove a duplicated documentation

2020-10-30T12:14:33+00:00

Perhaps due to a wrong cut-and-paste, this entry:

	What:		/sys/bus/vmbus/devices//channels//cpu

was added twice by the same patch, one following the other.

Remove the duplication.

Fixes: c2e5df616e1a ("vmbus: add per-channel sysfs info")
Acked-by: Wei Liu 
Acked-by: Jonathan Corbet 
Signed-off-by: Mauro Carvalho Chehab 
Link: https://lore.kernel.org/r/091e8de5543c280ceb47edcb3ab6d0e9f3fa085b.1604042072.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Expose monitor data only when monitor pages are used

2019-03-21T03:55:56+00:00

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

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

Drivers: hv: vmbus: add numa_node to sysfs

2018-07-29T06:09:56+00:00

Being able to find the numa_node for a device is useful for userspace
drivers (DPDK) and also for diagnosing performance issues.  This makes
vmbus similar to pci.

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

doc: fix sysfs ABI documentation

2018-05-14T14:06:48+00:00

In 4.9 kernel, the sysfs files for Hyper-V VMBus changed name but
the documentation files were not updated. The current sysfs file
names are /sys/bus/vmbus/devices//...

See commit 9a56e5d6a0ba ("Drivers: hv: make VMBus bus ids persistent")
and commit f6b2db084b65 ("vmbus: make sysfs names consistent with PCI")

Reported-by: Michael Kelley 
Signed-off-by: Stephen Hemminger 
Cc: stable@vger.kernel.org
Signed-off-by: K. Y. Srinivasan 
Signed-off-by: Greg Kroah-Hartman

uio_hv_generic: support sub-channels

2018-03-06T17:57:17+00:00

Use sysfs to allow supporting sub-channels. The userspace application
makes request to host to create sub-channels and the UIO kernel
driver populates the sysfs per-channel directory with a binary
attribute file that can be used to read/write ring.

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

vmbus: add monitor_id and subchannel_id to sysfs per channel

2018-01-09T18:50:42+00:00

Useful to identify which network queue is associated with
which vmbus channel.

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

vmbus: fix ABI documentation

2018-01-09T18:50:42+00:00

Fixes to vmbus ABI document including:
	- make it clear that relid is numeric value in sub directory
	- clarify interrupt mask description
	- spelling fixes
	- document regions

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