使用 Rust 编写的 RISC-V 超级管理程序
RVirt is an S-mode trap-and-emulate hypervisor for RISC-V. It is currently targeted at QEMU's virt machine type, but partially supports the HiFive Unleashed as well. It can run either on either the Berkeley Boot Loader or with its own (considerably faster) M-mode stub. It is powerful enough to run multiple instances of Linux as guest operating systems.
All three of the other projects can only run on processors that have hardware virtualization extensions like Intel VT-x or RISC-V's planned H-extension. Firecracker and Cloud Hypervisor additionally depend on KVM (and by extension the entire Linux kernel). By contrast, RVirt doesn't need KVM or Linux and can run on any sufficiently powerful 64-bit RISC-V processor with an MMU.
RISC-V is classically virtualizable which means that a hypervisor can rely on any privileged instruction triggering an illegal instruction fault when executed by the (unprivileged) guest OS. This is in contrast to other ISAs like x86 which have instructions that behave differently in user and kernel mode but never trap. Additionally, RISC-V has only 12 supervisor level control registers and only a handful of privileged instructions making the work to implement trap and emulate much more manageable.
Why not? Rust is a pleasant language to work with and can directly target bare metal platforms. I was also excited by Rust's ability to guarantee memory safety for safe code, but I found the amount of unsafe code required for initialization and vm entry/exit partially negated this benefit.
For more detailed instructions, see the getting started guide.
$ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
$ sudo apt-get install qemu-system-misc$ git clone https://github.com/mit-pdos/rvirt && cd rvirt$ wget https://fedorapeople.org/groups/risc-v/disk-images/vmlinux
$ mv vmlinux fedora-vmlinux
$ wget https://fedorapeople.org/groups/risc-v/disk-images/stage4-disk.img.xz
$ unxz stage4-disk.img.xz$ make qemuThis command launches an instance of QEMU with RVirt running inside and Linux running inside that. Once the boot process has completed you can SSH in through all the layers and directly interact with the guest (root password is 'riscv'):
$ ssh -p 10001 root@localhostRVirt supports running both inside an emulator and on real hardware and does runtime detection to learn what platform it is executing on. It has so far been tested with Fedora RISC-V builds, but may work with other distributions as well.
Tier 1: Boots fully and supports interaction via SSH / serial console
Tier 2: Boots partially but lacks driver support for block/network device to complete boot process
In addition to being able to boot and run a single guest, RVirt also supports some features not needed for the correct virtualization of a single guest:
Other features not used by Linux / not supported by current platforms are unlikely to be implemented:
暂无开放 Issues，或尚未同步最近议题。