selftests/resctrl: Split validate_resctrl_feature_request()

validate_resctrl_feature_request() is used to test both if a resource is
present in the info directory, and if a passed monitoring feature is
present in the mon_features file.

Refactor validate_resctrl_feature_request() into two smaller functions
that each accomplish one check to give feature checking more
granularity:
- Resource directory presence in the /sys/fs/resctrl/info directory.
- Feature name presence in the /sys/fs/resctrl/info/<RESOURCE>/mon_features
file.

Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Pass write_schemata() resource instead of test name

write_schemata() takes the test name as an argument and determines the
relevant resource based on the test name. Such mapping from name to
resource does not really belong to resctrlfs.c that should provide
only generic, test-independent functions.

Pass the resource stored in the test information structure to
write_schemata() instead of the test name. The new API is also more
flexible as it enables to use write_schemata() for more than one
resource within a test.

While touching the sprintf(), move the unnecessary %c that is always
'=' directly into the format string.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Introduce generalized test framework

Each test currently has a "run test" function in per test file and
another resctrl_tests.c. The functions in resctrl_tests.c are almost
identical.

Generalize the one in resctrl_tests.c such that it can be shared
between all of the tests. It makes adding new tests easier and removes
the per test if () forests.

Also add comment to CPU vendor IDs that they must be defined as bits
for a bitmask.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Create struct for input parameters

resctrl_tests reads a set of parameters and passes them individually
for each tests which causes variations in the call signature between
the tests.

Add struct input_params to hold all input parameters. It can be easily
passed to every test without varying the call signature.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Return -1 instead of errno on error

A number of functions in the resctrl selftests return errno. It is
problematic because errno is positive which is often counterintuitive.
Also, every site returning errno prints the error message already with
ksft_perror() so there is not much added value in returning the precise
error code.

Simply convert all places returning errno to return -1 that is typical
userspace error code in case of failures.

While at it, improve resctrl_val() comment to state that 0 means the
test was run (either pass or fail).

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Convert perror() to ksft_perror() or ksft_print_msg()

The resctrl selftest code contains a number of perror() calls. Some of
them come with hash character and some don't. The kselftest framework
provides ksft_perror() that is compatible with test output formatting
so it should be used instead of adding custom hash signs.

Some perror() calls are too far away from anything that sets error.
For those call sites, ksft_print_msg() must be used instead.

Convert perror() to ksft_perror() or ksft_print_msg().

Other related changes:
- Remove hash signs
- Remove trailing stops & newlines from ksft_perror()
- Add terminating newlines for converted ksft_print_msg()
- Use consistent capitalization
- Small fixes/tweaks to typos & grammar of the messages
- Extract error printing out of PARENT_EXIT() to be able to
differentiate

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Fix MBM test failure when MBA unavailable

Commit 20d96b25cc4c ("selftests/resctrl: Fix schemata write error
check") exposed a problem in feature detection logic in MBM selftest.
If schemata does not support MB:x=x entries, the schemata write to
initialize 100% memory bandwidth allocation in mbm_setup() will now
fail with -EINVAL due to the error handling corrected by the commit
20d96b25cc4c ("selftests/resctrl: Fix schemata write error check").
That commit just uncovers the failed write, it is not wrong itself.

If MB:x=x is not supported by schemata, it is safe to assume 100%
memory bandwidth is always set. Therefore, the previously ignored error
does not make the MBM test itself wrong.

Restore the previous behavior of MBM test by checking MB support before
attempting to write it into schemata which results in behavior
equivalent to ignoring the write error.

Fixes: 20d96b25cc4c ("selftests/resctrl: Fix schemata write error check")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Reduce failures due to outliers in MBA/MBM tests

The initial value of 5% chosen for the maximum allowed percentage
difference between resctrl mbm value and IMC mbm value in

commit 06bd03a57f8c ("selftests/resctrl: Fix MBA/MBM results reporting
format") was "randomly chosen value" (as admitted by the changelog).

When running tests in our lab across a large number platforms, 5%
difference upper bound for success seems a bit on the low side for the
MBA and MBM tests. Some platforms produce outliers that are slightly
above that, typically 6-7%, which leads MBA/MBM test frequently
failing.

Replace the "randomly chosen value" with a success bound that is based
on those measurements across large number of platforms by relaxing the
MBA/MBM success bound to 8%. The relaxed bound removes the failures due
the frequent outliers.

Fixed commit description style error during merge:
Shuah Khan <skhan@linuxfoundation.org>

Fixes: 06bd03a57f8c ("selftests/resctrl: Fix MBA/MBM results reporting format")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Make benchmark command const and build it with pointers

Benchmark command is used in multiple tests so it should not be
mutated by the tests but CMT test alters span argument. Due to the
order of tests (CMT test runs last), mutating the span argument in CMT
test does not trigger any real problems currently.

Mark benchmark_cmd strings as const and setup the benchmark command
using pointers. Because the benchmark command becomes const, the input
arguments can be used directly. Besides being simpler, using the input
arguments directly also removes the internal size restriction.

CMT test has to create a copy of the benchmark command before altering
the benchmark command.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: "Wieczor-Retman, Maciej" <maciej.wieczor-retman@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Simplify span lifetime

struct resctrl_val_param contains span member. resctrl_val(), however,
never uses it because the value of span is embedded into the default
benchmark command and parsed from it by run_benchmark().

Remove span from resctrl_val_param. Provide DEFAULT_SPAN for the code
that needs it. CMT and CAT tests communicate span that is different
from the DEFAULT_SPAN between their internal functions which is
converted into passing it directly as a parameter.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: "Wieczor-Retman, Maciej" <maciej.wieczor-retman@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Remove bw_report and bm_type from main()

bw_report is always set to "reads" and bm_type is set to "fill_buf" but
is never used.

Set bw_report directly to "reads" in MBA/MBM test and remove bm_type.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: "Wieczor-Retman, Maciej" <maciej.wieczor-retman@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Don't use variable argument list for ->setup()

struct resctrl_val_param has ->setup() function that accepts variable
argument list. All test cases use only 1 argument as input and it's
the struct resctrl_val_param pointer.

Instead of variable argument list, directly pass struct
resctrl_val_param pointer as the only parameter to ->setup().

Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan (Fujitsu) <tan.shaopeng@fujitsu.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Express span internally in bytes

MBA and MBM tests to use megabytes to represent span. CMT test uses
bytes. The difference requires run_benchmark() to size the buffer
differently based on the test name, which in turn requires passing the
test name into run_benchmark().

Convert MBA and MBM tests to use span internally in bytes like CMT test
to remove the internal inconsistency between the tests. Remove the test
dependent buffer sizing from run_benchmark().

This change eliminates one of the reasons why the test name has to be
passed around but there are still other users too so the test name
passing cannot yet be removed.

Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan (Fujitsu) <tan.shaopeng@fujitsu.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Convert span to size_t

Span is defined either as unsigned long or int.

Consistently use size_t everywhere for span as it refers to size of the
memory block.

Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan (Fujitsu) <tan.shaopeng@fujitsu.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Remove mum_resctrlfs from struct resctrl_val_param

Resctrl FS mount/umount are now cleanly paired leaving .mum_resctrlfs
in the struct resctrl_val_param unused.

Remove .mum_resctrlfs from struct resctrl_val_param.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan (Fujitsu) <tan.shaopeng@fujitsu.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Fix incorrect error return on test complete

An error snuck in between two recent conflicting changes:
Until recently ->setup() used negative values to indicate
normal test termination. This was changed in
commit fa10366cc6f4 ("selftests/resctrl: Allow ->setup() to return
errors") that transitioned ->setup() to use negative values
to indicate errors and a new END_OF_TESTS to indicate normal
termination.

commit 42e3b093eb7c ("selftests/resctrl: Fix set up schemata with 100%
allocation on first run in MBM test") continued to use
negative return to indicate normal test termination.

Fix mbm_setup() to use the new END_OF_TESTS to indicate
error-free test termination.

Fixes: 42e3b093eb7c ("selftests/resctrl: Fix set up schemata with 100% allocation on first run in MBM test")
Reported-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/lkml/bb65cce8-54d7-68c5-ef19-3364ec95392a@linux.intel.com/
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Remove duplicate codes that clear each test result file

Before exiting each test function(run_cmt/cat/mbm/mba_test()),
test results("ok","not ok") are printed by ksft_test_result() and then
temporary result files are cleaned by function
cmt/cat/mbm/mba_test_cleanup().
However, before running ksft_test_result(),
function cmt/cat/mbm/mba_test_cleanup()
has been run in each test function as follows:
cmt_resctrl_val()
cat_perf_miss_val()
mba_schemata_change()
mbm_bw_change()

Remove duplicate codes that clear each test result file,
while ensuring cleanup properly even when errors occur in each test.

Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Fix set up schemata with 100% allocation on first run in MBM test

There is a comment "Set up shemata with 100% allocation on the first run"
in function mbm_setup(), but there is an increment bug and the condition
"num_of_runs == 0" will never be met and write_schemata() will never be
called to set schemata to 100%. Even if write_schemata() is called in MBM
test, since it is not supported for MBM test it does not set the schemata.
This is currently fine because resctrl_val_parm->mum_resctrlfs is always 1
and umount/mount will be run in each test to set the schemata to 100%.

To support the usage when MBM test does not unmount/remount resctrl
filesystem before the test starts, fix to call write_schemata() and
set schemata properly when the function is called for the first time.

Also, remove static local variable 'num_of_runs' because this is not
needed as there is resctrl_val_param->num_of_runs which should be used
instead like in cat_setup().

Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Use remount_resctrlfs() consistently with boolean

remount_resctrlfs() accepts a boolean value as an argument. Some tests
pass 0/1 and some tests pass true/false.

Make all the callers of remount_resctrlfs() use true/false so that the
parameter usage is consistent across tests.

Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Allow ->setup() to return errors

resctrl_val() assumes ->setup() always returns either 0 to continue
tests or < 0 in case of the normal termination of tests after x runs.
The latter overlaps with normal error returns.

Define END_OF_TESTS (=1) to differentiate the normal termination of
tests and return errors as negative values. Alter callers of ->setup()
to handle errors properly.

Fixes: 790bf585b0ee ("selftests/resctrl: Add Cache Allocation Technology (CAT) selftest")
Fixes: ecdbb911f22d ("selftests/resctrl: Add MBM test")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Change a few printed messages

Change a few printed messages to report test progress more clearly.

Add a missing "\n" at the end of one printed message.

Suggested-by: Shuah Khan <shuah@kernel.org>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Skip the test if requested resctrl feature is not supported

There could be two reasons why a resctrl feature might not be enabled on
the platform
1. H/W might not support the feature
2. Even if the H/W supports it, the user might have disabled the feature
through kernel command line arguments

Hence, any resctrl unit test (like cmt, cat, mbm and mba) before starting
the test will first check if the feature is enabled on the platform or not.
If the feature isn't enabled, then the test returns with an error status.
For example, if MBA isn't supported on a platform and if the user tries to
run MBA, the output will look like this

ok mounting resctrl to "/sys/fs/resctrl"
not ok MBA: schemata change

But, not supporting a feature isn't a test failure. So, instead of treating
it as an error, use the SKIP directive of the TAP protocol. With the
change, the output will look as below

ok MBA # SKIP Hardware does not support MBA or MBA is disabled

Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Fix MBA/MBM results reporting format

MBM unit test starts fill_buf (default built-in benchmark) in a new con_mon
group (c1, m1) and records resctrl reported mbm values and iMC (Integrated
Memory Controller) values every second. It does this for five seconds
(randomly chosen value) in total. It then calculates average of resctrl_mbm
values and imc_mbm values and if the difference is greater than 300 MB/sec
(randomly chosen value), the test treats it as a failure. MBA unit test is
similar to MBM but after every run it changes schemata.

Checking for a difference of 300 MB/sec doesn't look very meaningful when
the mbm values are changing over a wide range. For example, below are the
values running MBA test on SKL with different allocations

1. With 10% as schemata both iMC and resctrl mbm_values are around 2000
MB/sec
2. With 100% as schemata both iMC and resctrl mbm_values are around 10000
MB/sec

A 300 MB/sec difference between resctrl_mbm and imc_mbm values is
acceptable at 100% schemata but it isn't acceptable at 10% schemata because
that's a huge difference.

So, fix this by checking for percentage difference instead of absolute
difference i.e. check if the difference between resctrl_mbm value and
imc_mbm value is within 5% (randomly chosen value) of imc_mbm value. If the
difference is greater than 5% of imc_mbm value, treat it is a failure.

Tested-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Call kselftest APIs to log test results

Call kselftest APIs instead of using printf() to log test results
for cleaner code and better future extension.

Suggested-by: Shuah Khan <skhan@linuxfoundation.org>
Tested-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Clean up resctrl features check

Checking resctrl features call strcmp() to compare feature strings
(e.g. "mba", "cat" etc). The checkings are error prone and don't have
good coding style. Define the constant strings in macros and call
strncmp() to solve the potential issues.

Suggested-by: Shuah Khan <skhan@linuxfoundation.org>
Tested-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Add MBM test

MBM (Memory Bandwidth Monitoring) test is the first implemented selftest.
It starts a stressful memory bandwidth benchmark and assigns the
bandwidth pid in a resctrl monitoring group. Read and compare perf IMC
counter and MBM total bytes for the benchmark. The numbers should be
close enough to pass the test.

Default benchmark is built-in fill_buf. But users can specify their
own benchmark by option "-b".

We can add memory bandwidth monitoring for multiple processes in the
future.

Co-developed-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Co-developed-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>