9P Filesystem for Haiku OS

A 9P2000.L filesystem implementation for Haiku OS, enabling file sharing between a QEMU host and Haiku guest via virtio-9p.

What is 9P?

9P is a network filesystem protocol from Plan 9. The 9P2000.L variant adds Linux compatibility. QEMU uses it for host-guest file sharing via virtio-9p.

Quick Start

On the Host (QEMU)

qemu-system-x86_64 \
    -enable-kvm -m 2G \
    -hda haiku.qcow2 \
    -virtfs local,path=/home/user/shared,mount_tag=host,security_model=mapped-xattr

In Haiku (Guest)

# Clone and build
git clone https://github.com/user/haiku-9p ~/9p
git clone https://review.haiku-os.org/haiku ~/haiku  # First time only

cd ~/9p
./build.sh setup
./build.sh install

# Mount shared folder
mkdir /mnt/host
mount -t 9p -o tag=host /mnt/host
ls /mnt/host

Documentation

• INSTALL.md - Full installation and usage guide
• docs/9P_PROTOCOL.md - 9P2000.L protocol reference
• tests/README.md - Testing guide

Features

• 9P2000.L protocol (Linux-compatible)
• Virtio-9p transport
• File read/write
• Directory listing
• File/directory creation and deletion
• Symbolic links
• File attributes (stat)
• Filesystem statistics

Project Structure

src/add-ons/kernel/file_systems/9p/
├── 9p.h              # Protocol definitions
├── 9p_message.cpp    # Message encoding/decoding
├── 9p_client.cpp     # 9P protocol client
├── virtio_9p.cpp     # Virtio transport
├── Volume.cpp        # VFS volume operations
├── Inode.cpp         # VFS inode operations
└── kernel_interface.cpp  # Module registration

Testing

cd tests

# Protocol unit tests (no server needed)
g++ -std=c++17 test_protocol.cpp -o test_protocol
./test_protocol

# Integration tests
g++ -std=c++17 test_9p_client.cpp -o test_9p_client
bash run_test.sh

License

MIT License - see source files for details.