VM switch verification

The VM switch verification option monitors filter drivers (extensible switch extensions) that run inside the Hyper-V Extensible Switch. Use this option to catch errors that occur in send or receive operations within the extensible switch.

Note  This option is available starting with Windows 8.1.

When this option is active, Driver Verifier will issue Bug Check 0xC4 (DRIVER_VERIFIER_DETECTED_VIOLATION) if the extensible switch extension fails to properly call Hyper-V extensible switch handler functions.

Activating this option

You can activate the VM switch verification feature for one or more drivers by using Driver Verifier Manager or the Verifier.exe command line. For details, see Selecting Driver Verifier Options. You must restart the computer to activate or deactivate the Power Framework Delay Fuzzing option.

  • At the command line

    At the command line, the VM switch verification is represented by verifier /flags 0x01000000 (Bit 24). To activate Power Framework Delay Fuzzing, use a flag value of 0x01000000 or add 0x01000000 to the flag value. For example:

    verifier /flags 0x01000000  /driver MyDriver.sys

    The feature will be active after the next boot.

  • Using Driver Verifier Manager

    1. Start Driver Verifier Manager. Type Verifier in a Command Prompt window.
    2. Select Create custom settings (for code developers) and then click Next.
    3. Select Select individual settings from a full list.
    4. Select (check) VM switch verification.
    5. Restart the computer.