Plan-Overview

1. Text-Based User Interface

  • A text-based interface is a good choice for simplicity and flexibility, especially for system administration tools.

  • Ensure the interface provides clear, structured output for device information.

  • Include help commands or documentation to guide users on how to interact with the tool and interpret the output.

2. Focus on PCI/PCIe

  • Centering the tool on PCI/PCIe is logical, as these are widely used standards for hardware interfacing.

  • Ensure the tool can handle both PCI and PCIe devices, as they share similarities but have differences in capabilities (e.g., PCIe has higher bandwidth and additional features).

  • Focus on querying and displaying device-specific information, such as:

    • Vendor ID, Device ID, and Class Code.

    • BAR (Base Address Registers) information.

    • Interrupts (e.g., MSI/MSI-X capabilities).

    • Power management states.

    • Link status (for PCIe devices, e.g., speed and width).

3. Device Discovery

  • User-Specified Device Path: Allow users to specify the device path (e.g., /sys/bus/pci/devices/0000:00:18.0) if they know the exact device they want to investigate.

  • Listing Devices: If the user doesn’t know the device path, provide an option to list all PCI/PCIe devices on the system. This should include:

    • Devices with drivers attached.

    • Devices without drivers attached (unclaimed devices).

    • Basic information for each device (e.g., vendor ID, device ID, class code, and device location).

  • Consider adding filters or search options to help users narrow down the list of devices (e.g., by vendor ID, device ID, or class code).

4. Device State Investigation

  • Focus on providing detailed and actionable information about device states. For example:

    • Device Status: Is the device enabled, disabled, or in a low-power state?

    • Driver Association: Which driver (if any) is currently associated with the device?

    • Resource Allocation: Display memory and I/O resources allocated to the device (e.g., BARs).

    • Interrupts: Show interrupt information, including whether MSI/MSI-X is enabled.

    • PCIe-Specific Information: For PCIe devices, display link status (speed, width) and capabilities (e.g., Advanced Error Reporting, ACS).

  • Consider adding a “verbose” mode to display even more detailed information for debugging or advanced use cases.

5. Error Handling and User Guidance

  • Provide clear error messages if the user inputs an invalid device path or if a device cannot be accessed.

  • Include a help command or documentation within the tool to explain how to use it and interpret PCI/PCIe device information.

  • Handle edge cases gracefully, such as devices that are not accessible or devices that return incomplete information.

6. Future Extensions

  • Advanced Querying: Add options to query specific device capabilities, such as DMA support, MSI/MSI-X interrupts, or power management states.

  • Logging and Debugging: Include logging capabilities to help diagnose issues or track device behavior during investigation.

  • Exporting Data: Allow users to export device information in a structured format (e.g., JSON or CSV) for further analysis or reporting.

7. Security Considerations

  • Ensure the tool requires appropriate privileges (e.g., root access) to interact with PCI/PCIe devices, as improper access could destabilize the system.

  • Validate user inputs to prevent potential security issues, such as path traversal attacks.

8. Testing and Validation

  • Plan for testing on a variety of PCI/PCIe devices to ensure compatibility and robustness.

  • Consider adding a “dry run” mode that simulates queries without making changes to the system, which can be useful for testing and debugging.

Summary

Your approach to building a PCI/PCIe-focused administration tool for investigating device states is well thought out. By focusing on querying and displaying detailed device information, providing clear user guidance, and ensuring robust error handling, you can create a valuable tool for system administrators and developers. Keep in mind the importance of security, testing, and future extensibility as you move forward with development.