Virtualization detection

LicenseSpring SDKs can detect virtualized, containerized, and cloud environments, and enforce a client-side policy that refuses to run when that policy is violated. This lets you tie a license to physical hardware even when raw hardware identifiers would otherwise reflect a VM rather than the host machine.

Legacy detector deprecated (SDK v8.9.0). The original approach described in earlier versions of this page — ExtendedOptions::enableVMDetection/isVMDetectionEnabled, Configuration::isVM/getDetectedVMName, and the separate Windows-only LicenseSpringVMD.dll ("Virtual Machine Detection" library) — is now [[deprecated]]. LicenseSpring no longer builds or ships that DLL, and the standalone VMDetection module has been removed from the SDK source tree. These calls remain only for minor-version source compatibility: on Windows they now report "no VM" unless an integrator still deploys their own copy of that DLL. The in-tree POSIX heuristic detector is unaffected and keeps running as before.

Use VirtualizationPolicy for all new integrations.

Migrating from the legacy detector (C++ SDK)

Legacy (deprecated)	Replacement	Notes
ExtendedOptions::enableVMDetection(true)	ExtendedOptions::setVirtualizationPolicy(policy)	Legacy detector needed a separate LicenseSpringVMD.dll on Windows. The new policy uses the cross-platform vm_detection module instead.
ExtendedOptions::isVMDetectionEnabled()	ExtendedOptions::getVirtualizationPolicy()	Policy is enforced once at least one environment class or platform is disallowed, rather than a single on/off flag.
Configuration::isVM()	Configuration::checkVirtualizationPolicy()	New call throws on violation instead of returning a bool.
Configuration::getDetectedVMName()	VirtualizationPolicy::getDisallowedPlatforms() set on the policy, matched by the vm_detection module	No direct 1:1 replacement, detected platform names now feed policy matching rather than a free-form getter.
VMDNotAvailableException	Handled via VirtualizationPolicy::disallowUndetermined() + VirtualEnvironmentNotAllowedException	Missing/failed detection module is now a policy choice, not always an error.
VMIsNotAllowedException	Unchanged — still reflects the server-side "Prevent Virtual Machine" license setting	Distinct from the new client-side VirtualEnvironmentNotAllowedException.
Ship LicenseSpringVMD.dll (Windows only)	Ship vm_detection.dll / libvm_detection.so / libvm_detection.dylib (all platforms)	Platform-specific name, loaded automatically when present alongside the app.

Prerequisites

You should have completed the Getting Started tutorial.

• Initialized LicenseManager (or LicenseHandler) with the appropriate settings.
• Created a LicenseID using either LicenseID::fromKey or LicenseID::fromUser, depending on your activation method.
• Implemented basic license management: activation and license checks.

Detected environment classes

Rather than a single VM name, the SDK classifies environments into VirtualEnvironment classes. A machine can match several at once, for instance a container running inside a cloud instance.

Class	Covers
VirtualMachine	VMware, VirtualBox, QEMU/KVM, Microsoft Hyper-V, Xen Project, Parallels Desktop, Windows Virtual PC, Virtual Iron, bhyve, Project ACRN, QNX Hypervisor, UTM
Container	Docker, LXC, OpenVZ, FreeBSD Jail, Linux containers
CompatibilityLayer	Wine, WSL / WSL2
HostHypervisor	The machine itself exposes a hypervisor interface (can run guests)
CloudInstance	AWS, Microsoft Azure, GCP, and similar

Configuring a policy

C++

VirtualizationPolicy policy;
policy.disallow(VirtualEnvironment::VirtualMachine);
policy.disallow(VirtualEnvironment::CloudInstance, false);
policy.setVMLikelihoodThreshold(VMLikelihood::Likely);
policy.disallowUndetermined(false);                        // default: allow if module is missing
policy.setDisallowedPlatforms({ "wine", "virtualbox" });   // optional, fine-grained

ExtendedOptions options;
options.setVirtualizationPolicy(policy);

std::shared_ptr<Configuration> configuration = Configuration::Create(
    EncryptStr("XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX"),
    EncryptStr("XXXXXXXXX-XXXXX-XXXXXXXXXXXXX_XXXXXX_XXXXXX"),
    EncryptStr("XXXXXX"),
    appName, appVersion, options);

C#

Coming soon.

Swift

Coming soon.

Python

Java

Go

JavaScript

A default-constructed VirtualizationPolicy disallows nothing. Enforcement only turns on once at least one environment class or platform is disallowed.

Deploying the detection module

Enforcement requires the LicenseSpring VM detection module alongside your application binary, loaded by its platform-specific name:

• Windows: vm_detection.dll
• Linux: libvm_detection.so
• macOS: libvm_detection.dylib

If the module is missing, the machine is treated as undetermined, or rejected if disallowUndetermined(true) is set on the policy.

Enforcing the policy

• Configuration::checkVirtualizationPolicy() - call explicitly, for example before activation.
• License::localCheck() - enforced automatically on every local check.

Both throw VirtualEnvironmentNotAllowedException when the machine violates the configured policy.

C++

try
{
    configuration->checkVirtualizationPolicy();
}
catch (const VirtualEnvironmentNotAllowedException &ex)
{
    // Machine violates the configured VirtualizationPolicy.
}

C#

Coming soon.

Swift

Coming soon.

Server-side "Prevent Virtual Machine" setting

Independent of the client-side policy above, a license can prevent activation on virtual machines through the LicenseSpring platform. Enabling Prevent Virtual Machine in the license settings blocks activation attempts within virtualized environments, so the software runs only on approved physical devices.

C++

if (license->isVMAllowed())
{
    // ...
}

C#

Coming soon.

Swift

Coming soon.

VMIsNotAllowedException is thrown when this platform-side policy is violated, distinct from VirtualEnvironmentNotAllowedException, which reflects the client-side VirtualizationPolicy.

Exceptions reference

Exception	Thrown when
VirtualEnvironmentNotAllowedException	The machine violates the client-side VirtualizationPolicy (checkVirtualizationPolicy() or License::localCheck()).
VMIsNotAllowedException	The server-side license setting is violated.
VMDNotAvailableException (deprecated)	Windows only: DLL not found, tampered with, or detection failed.