kvm_cpu_patch

This KVM kernel module patch helps evade CPU-based virtual machine detection and enhances CPU performance in virtual machines. Currently supports Intel processors only.

Features

• Authentic Hardware Monitoring
  Displays actual core temperature, frequency, voltage, etc., creating a more realistic virtual environment.

• Host Topology Exposure
  Reveals detailed host topology (e.g., P-Cores/E-Cores, Hyper-Threading), correct OS scheduling. Significantly improves multi-core performance and avoids VM detection based on thread/core mismatches.

• Intel V2 Topology Passthrough
  Directly passes Intel-specific V2 Extended Topology information, fixing Hyper-V nested virtualization failures on Intel CPUs.

• Performance Control MSR Passthrough
  Grants VMs access to host performance control MSRs. If supported by the host, VMs can overclock CPUs (e.g., via throttlestop).

Compilation

1. Download Linux kernel source code (this patch is based on 6.15.4).
2. Replace KVM module files in the kernel source tree with files from this project.
3. Compile the KVM module.

Usage

Step 1: Install the compiled KVM module

Step 2: Configure Libvirt XML

Mandatory: 1:1 vCPU-to-host-logical-CPU binding
Example for Intel i9-13900K (24 cores, 32 threads):

<vcpupin vcpu="0" cpuset="0"/>
<vcpupin vcpu="1" cpuset="1"/>
<vcpupin vcpu="2" cpuset="2"/>
<vcpupin vcpu="3" cpuset="3"/>
<vcpupin vcpu="4" cpuset="4"/>
<vcpupin vcpu="5" cpuset="5"/>
<vcpupin vcpu="6" cpuset="6"/>
<vcpupin vcpu="7" cpuset="7"/>
<vcpupin vcpu="8" cpuset="8"/>
<vcpupin vcpu="9" cpuset="9"/>
<vcpupin vcpu="10" cpuset="10"/>
<vcpupin vcpu="11" cpuset="11"/>
<vcpupin vcpu="12" cpuset="12"/>
<vcpupin vcpu="13" cpuset="13"/>
<vcpupin vcpu="14" cpuset="14"/>
<vcpupin vcpu="15" cpuset="15"/>
<vcpupin vcpu="16" cpuset="16"/>
<vcpupin vcpu="17" cpuset="17"/>
<vcpupin vcpu="18" cpuset="18"/>
<vcpupin vcpu="19" cpuset="19"/>
<vcpupin vcpu="20" cpuset="20"/>
<vcpupin vcpu="21" cpuset="21"/>
<vcpupin vcpu="22" cpuset="22"/>
<vcpupin vcpu="23" cpuset="23"/>
<vcpupin vcpu="24" cpuset="24"/>
<vcpupin vcpu="25" cpuset="25"/>
<vcpupin vcpu="26" cpuset="26"/>
<vcpupin vcpu="27" cpuset="27"/>
<vcpupin vcpu="28" cpuset="28"/>
<vcpupin vcpu="29" cpuset="29"/>
<vcpupin vcpu="30" cpuset="30"/>
<vcpupin vcpu="31" cpuset="31"/>

Note: The patch ignores QEMU topology settings and enforces host topology alignment. All vCPUs should be configured as logical cores.

<topology sockets="1" dies="1" cores="1" threads="32"/>