Bedrock

An experimental x86-64 hypervisor purpose-built for deterministic software testing.

Bedrock uses Intel VT-x to run guest VMs with fully emulated time (TSC), controlled randomness (RDRAND/RDSEED), various other device emulation, and copy-on-write VM forking - enabling reproducible execution for deterministic testing.

Architecture

┌────────────────────────────────────────────────────┐
│                    User Space                      │
│                                                    │
│  bedrock-vm      Rust library for VM control       │
│                                                    │
│                        │ ioctl                     │
├────────────────────────┼───────────────────────────┤
│                        ▼                           │
│                   Kernel Space                     │
│                                                    │
│  bedrock.ko      Kernel module (/dev/bedrock)      │
│                  - VMX setup and VM execution      │
│                  - EPT memory virtualization       │
│                  - Deterministic device emulation  │
│                  - ...                             │
│                                                    │
└────────────────────────────────────────────────────┘

Requirements

• Linux 6.18 host kernel with CONFIG_RUST=y
• Intel(R) Xeon(R) Gold 5412U (It should work on other modern Intel CPUs with VT-x support, but fine-tuning may be required)
• Patched linux 6.18 guest kernel (see guest-patches/)

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This project was created with heavy assistance from LLMs. Might freeze/hang or otherwise corrupt host machine, run at your own risk.