rvvisor

NOTE: This project is still work in progress!

rvvisor is a tiny hypervisor written in Rust, which partially supports RISC-V Hypervisor Extension v0.6.1 included in Volume II: RISC-V Privileged Architectures V1.12-draft).

Requirements

This project relies on the following tools.

• riscv/riscv-gnu-toolchain
• QEMU with RISC-V Hypervisor Extension Emulation

To run rvvisor, you need to install them and configure your PATH first.

Usage

Here's a list of the possible usecases:

• Run rvvisor with an example kernel
• (in the future) Run our hypervisor with your own kernel

Run rvvisor with an example kernel

You can run the simple guest kernel, whose implementation is in ./guest directory, as follows.

rustup target add riscv64gc-unknown-none-elf || true

# build hypervisor
cd hypervisor
CC=riscv64-unknown-linux-gnu-gcc cargo build
cd ..

# build guest
cd guest
CC=riscv64-unknown-linux-gnu-gcc cargo build
cd ..

# run hypervisor with guest
cd hypervisor
cargo run -- -drive file=../guest/target/riscv64gc-unknown-none-elf/debug/riscv-virt-guest,if=none,format=raw,id=x0 -device virtio-blk-device,drive=x0,bus=virtio-mmio-bus.0

Run rvvisor with your own kernel

Currently, due to the lack of features, famous kernels like xv6-riscv or Linux do NOT work upon rrvisor.

NOTE: Debug rvvisor with GDB

You can debug rvvisor with gdb like this:

# in a shell ...
$ cargo run -- -S -gdb tcp::9999 # + additional opts

# in another shell ...
$ riscv64-unknown-linux-gnu-gdb target/riscv64gc-unknown-none-elf/debug/rvvisor
...
(gdb) target remote localhost:9999
(gdb) continue

Features (to be supported)

rvvisor currently supports the following features:

• :construction: Run a single VM upon rvvisor
  • [x] load ELF image into the memory space of a VM
  • [x] jump to the kernel image loaded to a VM image whiel enabling guest physical address translation by hgatp
  • [x] run a tiny kernel which does not require any external hardwares like disk devices
  • [ ] handle read/write requests for CSRs from a guest
  • [ ] handle SBI calls
• [ ] Run multiple VMs upon rvvisor
  • [ ] switch CPU contexts among guests
  • [ ] schedule the guest in a fancy way
• [ ] Support multi-core host environment
• [ ] Support device virtualization
  • [ ] block device
  • [ ] network device
  • [ ] input device
  • [ ] display device