Is the List Architecture-Specific or Generic?

The list provided is generic and represents the typical files and directories you would find in /sys/bus/pci/devices/0000:00:18.x on a Linux system. However, there are some nuances to consider.

Generic Nature of the List

• The files and directories listed are common across most Linux systems and architectures (e.g., x86, ARM, PowerPC).

• These files are part of the Linux kernel’s sysfs interface, which standardizes how device information is exposed to userspace.

• For example, files like vendor, device, class, resource, and driver are present on almost all systems with PCI devices.

Architecture-Specific or Hardware-Specific Variations

While the list is generic, some files or directories may vary depending on:

• Architecture: For example, ARM-based systems might have additional or different files related to platform-specific PCI implementations.

• Kernel Version: Newer kernels may expose additional files or directories, while older kernels might lack some of them.

• Hardware Features: If the PCI device supports specific features (e.g., SR-IOV, AER, ASPM), the corresponding files (e.g., sriov_numvfs, pcie_aer/) will be present. If the hardware doesn’t support these features, the files won’t exist.

• Driver Implementation: Some files (e.g., driver_override, uevent) depend on how the device driver interacts with the kernel.

Examples of Architecture-Specific or Hardware-Specific Files

Here are some examples of files or directories that might not be present on all systems:

SR-IOV-Related Files

• sriov_numvfs, sriov_totalvfs, physfn/, virtfn0/, etc.

• These only exist if the device supports SR-IOV (Single Root I/O Virtualization).

PCIe-Related Files

• pcie_link_width, pcie_link_speed, pcie_aer/, pcie_aspm/, etc.

• These are specific to PCI Express (PCIe) devices and won’t exist for older PCI devices.

IOMMU-Related Files

• iommu_group/, iommu/

• These depend on whether the system has an IOMMU (Input-Output Memory Management Unit) and whether it’s enabled.

NUMA-Related Files

• numa_node

• This file is only relevant on systems with NUMA (Non-Uniform Memory Access) architecture.

How to Check for Specific Files

If you’re unsure whether a file or directory exists on your system, you can use the following command to list the contents of the directory for a specific device:

ls /sys/bus/pci/devices/0000:00:18.0

Replace 0000:00:18.0 with the actual device address you’re investigating.

Summary

• The list is generic and applies to most Linux systems with PCI devices.

• Some files or directories may not exist depending on the architecture, kernel version, hardware features, or driver implementation.

• If you’re working on a specific architecture or hardware platform, you may encounter additional files or directories not included in the generic list.

If you’re working on a specific architecture or hardware platform and notice differences, feel free to share the details, and I can help you interpret or adapt the list accordingly!