NVIDIA Driver Differ

This tool is intended to help adoption of new NVIDIA driver versions. It compares two driver versions (one currently supported by nvproxy and one that is not) and reports any changes to ioctl structs that exists between the two versions. However, it only does this for ioctl structs that are currently supported by nvproxy, giving a targeted but comprehensive understanding of what changes need to be reflected in nvproxy to support the newer driver version.

To do this, the tool needs to parse the NVIDIA driver source code. This is done using Clang's AST Matcher API to generate an AST of the NVIDIA driver, which the tool then searches and traverses to get a comprehensive definition of every struct nvproxy relies on.

Usage

Everything is packaged for convenience inside run_differ. The differ accepts two version numbers as arguments: a base version which is currently supported in nvproxy, and a next version that is compared against base. For example, comparing versions 550.90.07 and 560.31.02 can be done like so:

make run TARGETS=//tools/nvidia_driver_differ:run_differ ARGS="--base 550.90.07 --next 560.31.02"

This will fetch the corresponding source code from Github, parse it using Clang, and then compare the definitions that were found. Any differences will be printed to standard output. These differences can be additions of new fields to structs, or changes to the name or type of existing fields. For example:

struct NEW_FIELD_EXAMPLE
  []parser.RecordField{
    ... // 10 identical elements
+   s"bool newField1"
+   s"int newField2"
  }

struct MODIFIED_FIELD_EXAMPLE
  []parser.RecordField{
    ... // 10 identical elements
    {
-     Name:   "oldName",
+     Name:   "newName",
      Type:   "int",
      Offset: 36
    },
    {
      Name:   "arrayField",
-     Type:   "int[10]",
+     Type:   "int[12]",
      Offset: 40
    },
  }

A deeper dive into how this tool works can be found here.