rustvmm_gen: Introduce rustvmm_gen.py

`rustvmm_gen.py` integrates kernel version checking, source extraction,
compilation and header installation. Header files could be prepared with
command:

```command
./rustvmm_gen/rustvmm_gen.py --arch <arm64/x86_64/riscv> --version <X.Y/X.Y.Z> prepare
```

Source code required by `seccompiler` could be generated with command:

```command
./rustvmm_gen/rustvmm_gen.py --arch <arm64/x86_64/riscv> --version <X.Y/X.Y.Z> generate_syscall
```

Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>

scripts/rustvmm_gen.py

@@ -0,0 +1,101 @@
+#!/usr/bin/env python3
+#
+# Copyright 2025 © Institute of Software, CAS. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+import argparse
+import os
+from pathlib import Path
+from lib.kernel_source import (
+    check_kernel_version,
+    create_temp_dir,
+    download_kernel,
+    extract_kernel,
+    install_headers,
+)
+from lib.syscall import (
+    generate_syscall_table,
+    generate_rust_code,
+)
+
+# Map arch used in linux kernel to arch understandable for Rust
+MAP_RUST_ARCH = {"arm64": "aarch64", "x86_64": "x86_64", "riscv": "riscv64"}
+
+
+def prepare_command(args):
+    check_kernel_version(args.version)
+
+    # Create `temp_dir` under `/tmp`
+    temp_dir = create_temp_dir(args.version)
+
+    # Download kernel tarball from https://cdn.kernel.org/
+    tarball = download_kernel(args.version, temp_dir)
+
+    # Extract kernel source
+    src_dir = extract_kernel(tarball, temp_dir)
+
+    # Get headers of specific architecture
+    installed_header_path = install_headers(
+        src_dir=src_dir,
+        arch=args.arch,
+        install_path=args.install_path,
+    )
+
+    print(f"\nSuccessfully installed kernel headers to {installed_header_path}")
+    return src_dir
+
+
+def generate_syscall_command(args):
+    src_dir = prepare_command(args)
+
+    # Generate syscall table
+    header_path = os.path.join(
+        os.path.dirname(src_dir), f"{args.arch}_headers/include/asm/unistd_64.h"
+    )
+    syscalls = generate_syscall_table(header_path)
+
+    # Create output directory if needed
+    args.output_path.mkdir(parents=True, exist_ok=True)
+
+    # Generate architecture-specific filename
+    output_file_path = args.output_path / f"{MAP_RUST_ARCH[args.arch]}.rs"
+
+    # Generate Rust code
+    generate_rust_code(syscalls, output_file_path)
+
+
+def main():
+    parser = argparse.ArgumentParser(prog="rustvmm_gen")
+    subparsers = parser.add_subparsers(dest="command", required=True)
+    parser.add_argument("--arch", help="Target architecture (x86_64, arm64, riscv64)")
+    parser.add_argument("--version", help="Kernel version (e.g. 6.12.8)")
+    parser.add_argument(
+        "--install_path",
+        default=None,
+        help="Header installation directory path",
+    )
+    parser.add_argument("--keep", help="Keep temporary build files")
+
+    # Prepare subcommand
+    prepare_parser = subparsers.add_parser("prepare", help="Prepare kernel headers")
+    prepare_parser.set_defaults(func=prepare_command)
+
+    # Generate syscall subcommand
+    generate_syscall_parser = subparsers.add_parser(
+        "generate_syscall",
+        help="Generate syscall for `rust-vmm/seccompiler` from prepared kernel headers",
+    )
+    generate_syscall_parser.add_argument(
+        "--output_path",
+        type=Path,
+        default=os.getcwd(),
+        help="Output directory path (default: current)",
+    )
+    generate_syscall_parser.set_defaults(func=generate_syscall_command)
+
+    args = parser.parse_args()
+    args.func(args)
+
+
+if __name__ == "__main__":
+    main()