如何计算WDM内核模式驱动程序的最大CPU频率？

Question

问题在于：我试图根据IOCTL sample skeleton在内核模式WDM驱动程序中计算CPU频率，但如果我尝试使用QueryPerformanceFrequency或者它不想编译QueryPerformanceCounter的。我觉得可能是因为它的内核模式驱动程序不允许我包含Windows.h，其中包含这些方法 - it forces me to use Ntddk.h instead。

通常我会在Win32控制台应用程序中使用此功能来计算此信息，但由于它不会影响Intel CPU上的Turbo Boost，因此不准确：

float GetCoreFrequency()
{
    // __rdtsc: Returns the processor time stamp which records the number of clock cycles since the last reset.
    // QueryPerformanceCounter: Returns a high resolution time stamp that can be used for time-interval measurements.
    // Get the frequency which defines the step size of the QueryPerformanceCounter method.
    LARGE_INTEGER frequency;
    QueryPerformanceFrequency(&frequency);
    // Get the number of cycles before we start.
    ULONG cyclesBefore = __rdtsc();
    // Get the start time.
    LARGE_INTEGER startTime;
    QueryPerformanceCounter(&startTime);
    ULONG cyclesAfter;
    LARGE_INTEGER endTime;
    // Get the number of cycles over some arbitrary but short enough period of time.
    do
    {
        cyclesAfter = __rdtsc();
        QueryPerformanceCounter(&endTime);
    } while ((endTime.QuadPart - startTime.QuadPart) / frequency.QuadPart < 1);
    // Return the number of MHz.
    return (cyclesAfter - cyclesBefore)*pow(10, -6) / ((endTime.QuadPart - startTime.QuadPart) / frequency.QuadPart);
}

actual formula for CPU frequency on Intel chips是最大频率乘以可从芯片本身的两个CPU寄存器（APERF和MPERF）获得的比率：

frequency = maximumFrequency * APERF / MPERF;

转换为此代码：

frequency = maximumFrequency * __readmsr(232) / __readmsr(231);

我希望能够从QueryPerformanceFrequency获得最大频率，但由于我无法将其包括在内，我如何才能获得最大频率？