Alioth

Alioth /AL-lee-oth/ is an experimental KVM-based type-2 hypervisor (virtual machine monitor) in Rust implemented from scratch.

Important

Disclaimer: Alioth is not an officially supported Google product.

Quick start

Install Alioth from source,

cargo install alioth-cli --git https://github.com/google/alioth.git

Make an initramfs with u-root.

Boot a Linux kernel with 2 CPUs and 4 GiB memory,

alioth -l info --log-to-file \
    run \
    --kernel /path/to/vmlinuz \
    --cmd-line "console=ttyS0" \
    --initramfs /path/to/initramfs \
    --memory size=4G \
    --num-cpu 2

Features

Runs on x86_64 and aarch64.
Boots confidential VMs with AMD SEV, SEV-ES, or SEV-SNP, see coco.md for details.
VirtIO devices
- net backed by a tap device,
- vsock backed by host /dev/vhost-vsock,
- blk backed by a raw-formatted image,
- entropy backed by host /dev/urandom,
- fs backed by virtiofsd with experimental Direct Access (DAX),
- (WIP) balloon with free page reporting.
PCI device passthrough based on VFIO/IOMMUFD.
Other devices
- serial console: 16450 on x86_64, pl011 on aarch64,
- fw_cfg (QEMU Firmware Configuration Device),
- pvpanic.

TODOs

explore a better solution to ACPI DSDT to replace the pre-compiled AML bytes,
increase test coverage,
add missing documents,
[ ](long term) port Alioth to Apple's Hypervisor framework,
performance, performance, and performance!

Acknowledgment

The virtualization implementation in Alioth takes the following projects as references,

The error handling practice is inspired by GreptimeDB's stack_trace_debug.