Description xiaochenshen 2022-09-30 11:55:39 UTC

Description of problem:

1. Issue 1 - batch related values for IAA are incorrect 
From Intel IAA spec [1], Intel IAA does not support batch processing.
Two batch related default values for IAA are incorrect in current code:
(1) The max batch size of device is set during device initialization,
    that indicates batch is supported. It should be always 0 on IAA.
(2) The max batch size of work queue is set to WQ_DEFAULT_MAX_BATCH (32)
    as the default value regardless of Intel DSA or IAA device during
    work queue setup and cleanup. It should be always 0 on IAA.

Fix the issues by setting the max batch size of device and max batch
size of work queue to 0 on IAA device, that means batch is not
supported.

2. Issue 2 - batch related sysfs attributes should be invisible
In current code, dev.max_batch_size and wq.max_batch_size attributes in
sysfs are exposed to user to show or update the values.

From Intel IAA spec [1], Intel IAA does not support batch processing. So
these sysfs attributes should not be supported on IAA device.

Fix this issue by making the attributes of max_batch_size invisible in
sysfs through is_visible() filter when the device is IAA.


Version-Release number of selected component (if applicable):
ANCK 5.10 Dev.


How reproducible:
Always.


Steps to Reproduce:
# modprobe idxd
# cat /sys/bus/dsa/devices/dsa0/max_batch_size
1024
# cat /sys/bus/dsa/devices/dsa0/wq0.0/max_batch_size
32

# cat /sys/bus/dsa/devices/iax1/max_batch_size
1
# cat /sys/bus/dsa/devices/iax1/wq1.0/max_batch_size
32


Actual results:
# cat /sys/bus/dsa/devices/iax1/max_batch_size
1
# cat /sys/bus/dsa/devices/iax1/wq1.0/max_batch_size
32


Expected results:
These two sysfs attributes should be invisible:
# cat /sys/bus/dsa/devices/iax1/max_batch_size
# cat /sys/bus/dsa/devices/iax1/wq1.0/max_batch_size


Additional info:
This issue is reproducible in latest upstream kernel. So we need upstream fixing.