# ionescu007/SimpleVisor

SimpleVisor is a simple, portable, Intel VT-x hypervisor with two specific goals: using the least amount of assembly code (10 lines), and having the smallest amount of VMX-related code to support dynamic hyperjacking and unhyperjacking (that is, virtualizing the host state from within the host). It works on Windows and UEFI.

Repository: https://github.com/ionescu007/SimpleVisor
Canonical: https://ross.abutalabs.com/products/simplevisor
Homepage: http://ionescu007.github.io/SimpleVisor/
Language: C
License Family: other
Last push: 2024-05-08T14:28:23+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 3822, "days_push": 847, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1985, forks 282 (observed 2026-08-28T04:06:02.566946+00:00)

## What it is
SimpleVisor is a minimal, portable Intel VT-x hypervisor written in about 500 lines of C and 10 lines of assembly, supporting dynamic hyperjacking and unhyperjacking of the host. It runs on 64-bit Windows and in UEFI environments and serves primarily as an educational reference for learning how hypervisors work.

## Use cases
- learn how Intel VT-x hypervisors work
- study minimal VMX hyperjacking code
- virtualize the host from within the host on Windows
- experiment with EPT and VPID in a small codebase
- run a hypervisor in a UEFI environment
- understand VMX root and non-root operation

## When to choose
- you want a small, heavily commented codebase to learn hypervisor internals
- you need dynamic load/unload of a VT-x hypervisor on 64-bit Windows
- you want a starting point for building your own hypervisor
- you need a UEFI-mode hypervisor experiment

## When to avoid
- you need a production-grade hypervisor with full multiprocessor and OS-boot support from UEFI
- your machine already runs under Hyper-V, Xen, or another hypervisor
- you need 32-bit x86, Windows 7, or pre-Nehalem CPU support
- you need a full-featured virtualization product like VirtualBox or KVM

## Facets
- artifact type: library
- maturity: maintenance
- function: developer-tools, security
- domain: operating-systems, developer-tools, security, hardware
- platform: windows, cpp, c
- tags: hypervisor, intel-vt-x, hyperjacking, uefi, vmx, ept, educational, kernel-driver, virtualization

## Member repositories
- ionescu007/SimpleVisor (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:02.566946+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T03:03:17.123527+00:00, confidence not recorded.
  - readme: https://github.com/ionescu007/SimpleVisor (fetched 2026-08-28T04:06:02.566946+00:00, sha a06a1d343cb1)
  - homepage: http://ionescu007.github.io/SimpleVisor/ (fetched 2026-08-29T10:42:59.754741+00:00, sha 79659e66a502)
- Data as of 2026-08-30T08:39:29.467469+00:00.