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• Check if wperf-driver correctly loads and unloads its resources.

• Implement PMU (driver) resource acquisition lock and release.

  • wperf-driver should be able to release PMU resources if they are not used by user space application wperf.

• Make sure only one user space application can access wperf-driver’s PMU resources.

• Introduce “busy” state to wperf-driver.

  • All wperf user space instances should be able to tell if driver is currently “in use” by another wperf instance(s).

  • Note: this will be extended in Device Tree feature. Each driver will be able to communicate user space if resource is ready, acquired and ready to use (other “states” may be added later).

    • In DT architecture there will be N drivers, user space can acquire driver(s) leaving other driver for users' disposal. Currently if user space is for example counting core, other wperf instance can’t use DMC resource.

unCore PMU Driver Improvements

Current wperf-driver implementation is not auto detecting unCore PMU.

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• Currently wperf user space application is using cfgmgr32.lib to detect uncore PMU resources. We should be able to move this to the driver side.

Driver Verifier

Driver Verifier monitors Windows kernel-mode drivers and graphics drivers to detect illegal function calls or actions that might corrupt the system. Driver Verifier can subject Windows drivers to a variety of stresses and tests to find improper behavior. See

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• Isolate and fix most critical findings from DV.

• Other (sort out other issues that may influence driver’s performance or stability).

wperf-devgen

Project wperf-devgen is a help utility to install the WindowsPerf Driver using the Software Device API.

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• Code review of current solution.

• Fix issue related to device being uninstalled after restart.

• Add bulletproof install / remove / driver status functionality to wperf-devgen.

  • Note: in the future we will introduce Device Tree feature.

    • This will expand on wperf-devgen tool which should be able to manage set of WindowsPerf drivers.

Driver Testing Framework

Current project lacks wperf-driver testing infrastructure. WindowsPerf DTF should introduce simple smoke test / canary test framework we can use to verify driver during development and CI/CD testing. Current

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• Add stress tests for wperf-driver features.

• Add stress test for driver load/unload functionality.

• Add stress test for driver install / remove functionality.

• Add tests and checks based on Driver Verifier

• Add tests for functionality we’ve added with beta branch https://gitlab.com/Linaro/WindowsPerf/windowsperf/-/tree/beta?ref_type=heads.

Vulnerability analysis

The current driver never went through any sort of analysis of possible security vulnerabilities. We need to evaluate and solve all issues.

Goal: Evaluate and report possible driver vulnerabilities and solve them.

IOCTRL

• Check and refactor / evaluate IOCTRL strategy.

Misc

• Evaluate all DPCs and interrupt handlers. We want to make sure each DPC and interrupt handle is efficient.

  • See example issue

    Jira Legacy
    server System JIRA serverId 59107c6f-1e52-32bc-b58f-400d54bba998 key WPERF-451

    where we use few events to count. We want to make sure all interrupts are being handled so that user space can collect from driver accurate sapling data.

• Evaluate changes done in https://gitlab.com/Linaro/WindowsPerf/windowsperf/-/tree/beta?ref_type=heads.

  • Add testing when one or more GPCs are not available.

  TBD

  • .

• Functions inside device.c are too big and complex, we want all this to be broken down and become more easily maneageable.

• Looks like when we stop counting/sampling some events are spilled over to the next iteration. See comments on [wperf-scripts] Add to regression tests sleep between core loads (!389) · Merge requests · linaro / WindowsPerf / WindowsPerf · GitLab and here [wperf-driver] Reset the counters on PMU_CTL_RESET (!388) · Merge requests · linaro / WindowsPerf / WindowsPerf · GitLab