lirent
ec27a8f4e5
Phase 0. Replace the spoof-hv knob with spoof-mode, a first-class selector modeled as two axes (persona x presence) exposed as 4 presets: - none: stock (spoof_on now requires mode != none, killing half-spoof states) - hyperv: Microsoft Virtual Machine persona + Hyper-V presence (honest child VM) - vbs (seeded default): real-OEM persona + Hyper-V presence (mimic physical Win11+VBS) - physical: real-OEM persona + bare metal Engine: spoof_mode()/spoof_persona_msvm()/spoof_presence_hyperv() in spoof-core; the hv/waet/pvpanic/vmgenid policies now derive from the mode. microsoft-vm persona wired across platform (ACPI OEM VRTUAL/MICROSFT, Microsoft Corporation), system type1 (Virtual Machine), storage (Virtual HD / Msft Virtual DVD-ROM) and EDID (MSF/Hyper-V). New getters spoof_system_manufacturer/product (type1, real-OEM or Hyper-V). Patches: 0002 registers spoof-mode; 0024 now also forces type1 system identity. spoof-hv kept as a back-compat alias. Inert without a seed. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
114 lines
4.7 KiB
Markdown
114 lines
4.7 KiB
Markdown
# qemu-spoof
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Seed-driven, **per-VM** hardware-identity anti-detection for QEMU / Proxmox VE —
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a drop-in `pve-qemu-kvm` build. Each VM derives a *coherent, unique* hardware
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persona from a per-VM seed, so a fleet of VMs does not share one fingerprint, and
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with **no seed it falls back to stock QEMU** (zero behaviour change).
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## Why seed-driven (not a static fork)
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A hard-coded anti-detect fork gives every VM the *same* firmware/bus identity
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(same ACPI OEM, same fw_cfg signature, same PCI IDs, same monitor) — which is
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itself a **fleet fingerprint**: many VMs with identical "hardware" correlate
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trivially. qemu-spoof instead derives a **coherent persona from a per-VM seed**,
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so each VM looks like a different real machine while staying internally
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consistent (CPU vendor ↔ chipset ↔ ACPI OEM ↔ board ↔ socket all cohere).
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## How it works
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A small in-tree module (`hw/misc/spoof.c`, source kept in `src/`) holds pools of
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real identities and a pure derivation `seed -> splitmix64 -> pool pick`. Every
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anti-detect call site is patched from a hard-coded literal to a getter:
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```c
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- memcpy(signature, "KVMKVMKVM\0\0\0", 12);
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+ memcpy(signature, spoof_kvm_signature("KVMKVMKVM\0\0\0"), 12);
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```
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The getter returns the seed-derived value, or the **stock default** when no seed
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is set — so the patch is inert until a VM opts in.
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### Seed input
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```
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-machine <type>,...,spoof-seed=<string> # preferred (Proxmox: via args)
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QEMU_SPOOF_SEED=<string> # env fallback (testing)
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```
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Same seed → same persona. Mix in a host secret so personas are not guessable from
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the vmid. Proxmox: add `spoof-seed=` through the VM `args:` line.
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### Modes
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`-machine ...,spoof-mode=` selects the identity strategy (two axes — hardware
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persona × hypervisor presence — as presets):
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| mode | persona | presence | looks like |
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|---|---|---|---|
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| `none` | stock | KVM | a plain VM (no spoof) |
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| `hyperv` | Microsoft "Virtual Machine" | Hyper-V | an honest Hyper-V guest |
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| `vbs` (default when seeded) | real OEM | Hyper-V | a physical Win11 box with VBS on |
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| `physical` | real OEM | bare metal | a physical machine (no hypervisor) |
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The presence axis (clearing the hypervisor bit / Hyper-V enlightenments) is partly
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the CPU model configuration (`cpu: host,hidden=1` + `hv-*`); set it to match the mode.
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## Layout
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```
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pve-qemu/ git submodule -> https://git.proxmox.com/git/pve-qemu.git (pinned)
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src/spoof*.{c,h} the seed-driven identity module (decomposed by aspect)
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patches/ quilt patches injected into pve-qemu/debian/patches/series:
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0002 register the spoof-seed machine property
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0010+ wire each anti-detect call site to a getter
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Makefile prepare -> build the .deb
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```
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## Build
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```sh
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git submodule update --init --recursive # pve-qemu + its qemu submodule
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make prepare # inject spoof module + patches + changelog
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make deb # dpkg-buildpackage -> pve-qemu/*.deb
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```
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Builds on Debian trixie (matches pve-qemu 11.0). Use a clean builder / WSL, never
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a production node. `make deb` produces `pve-qemu-kvm_*_amd64.deb` (+ `-dbgsym`).
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## Packaging & delivery
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Install the built `.deb` on a Proxmox VE node in place of the stock package, or
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serve it from any apt repository (e.g. a Debian package registry).
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### Surviving Proxmox updates (epoch + per-commit revision)
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The Makefile stamps an **epoch** — `1:<upstream>+qemu-spoofN`, where `N` is the
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commit count — so the package permanently outranks stock `pve-qemu-kvm` (no
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epoch). An `apt upgrade` from the Proxmox repo therefore never reverts the spoof;
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you are the source of truth for this package on your nodes. Pull upstream QEMU
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fixes deliberately by rebuilding on a newer `pve-qemu` (the epoch carries
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forward). Optional belt-and-suspenders apt pin on each node:
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```
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Package: pve-qemu-kvm
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Pin: origin <your-apt-registry-host>
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Pin-Priority: 1001
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```
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## Companion config (machine options, not code)
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A few tells are configuration, not code — set them when provisioning a spoofed VM
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(alongside the `spoof-seed`):
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- `-machine ...,vmport=off` — disable the VMware backdoor port (0x5658)
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- prefer real-id emulated devices over virtio where stealth matters: `e1000e` NIC,
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SATA/AHCI disk (their PCI vendor:device are real Intel; virtio's `1af4` is a tell
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and its id cannot be spoofed without breaking the guest driver)
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- GPU: vfio passthrough with `x-pci-vendor-id/...` overrides
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- CPU: `host,hidden=1` (+ hv enlightenments for Windows) to back the `spoof-hv` policy
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## License
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Patches and module are derivative of QEMU and licensed under **GPL v2** (the QEMU
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license). See the COPYING file in the QEMU tree.
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