Hypervisor Versioning

Note   Client operating systems are strongly encouraged to check for hypervisor features by using CPUID leaves 0x40000003 through 0x40000005 instead of by comparing against version ranges.

The hypervisor version information is encoded in CPUID leaf 0x40000002. This leaf provides the main version and the service version numbers.

The main version includes major and minor version numbers and a build number. These version and build numbers correspond to Microsoft Windows release numbers. The service version describes the changes that are made to the main version.

For maximum forward compatibility, clients should use greater-than-or-equal tests to validate their version information against the hypervisor version information. For example, when they check main versions, clients should use greater-than-or-equal tests and not equality tests. The following pseudo-code demonstrates the method that clients should use when they compare version numbers, which consist of both the main and service versions:

if <your-main-version> greater than <hypervisor-main-version>
{
 your version is compatible
}
else if <your-main-version> equal to <hypervisor-main-version>
and
        <your-service-version> greater than or equal to
                                     <hypervisor-service-version>
{
 your version is compatible
}
else
{
 your version is NOT compatible
}

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Build date: 11/16/2013