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Virtual Function Management Extension

Virtual Function Management Extension

API

Virtual Function Management

This feature adds the ability to retrieve telemetry from PF domain for monitoring per VF memory and engine utilization. This telemetry is used to determine if a VM has oversubscribed GPU memory or observe engine business for a targeted workload. If VF has no activity value to report, then implementation shall reflect that appropriately in zes_vf_util_engine_exp_t struct so that percentage calculation results in value of 0.

The following pseudo-code demonstrates a sequence for obtaining the engine activity for all Virtual Functions from Physical Function environment:

// Gather count of VF handles
uint32_t numVf = 0;
zes_vf_exp_properties_t vfProps {};
zesDeviceEnumActiveVFExp(hDevice, &numVf, nullptr);

// Allocate memory for vf handles and call back in to gather handles
std::vector<zes_vf_handle_t> vfs(numVf, nullptr);
zesDeviceEnumActiveVFExp(hDevice, &numVf, vfs.data());

// Gather VF properties
std::vector <zes_vf_exp_properties_t> vfProps(numVf);
for (uint32_t i = 0; i < numVf; i++) {
    zesVFManagementGetVFPropertiesExp(vfs[i], &vfProps[i]);
}

// Detect the info types a particular VF supports

// Using VF# 0 to demonstrate how to detect engine info type and query engine util info
zes_vf_handle_t activeVf = vfs[0];
uint32_t count = 1;
if (vfProps[0].flags & ZES_VF_INFO_ENGINE) {
    zes_vf_util_engine_exp_t engineUtil0 = {};
    zesVFManagementGetVFEngineUtilizationExp(activeVf, &count, &engineUtil0);
    sleep(1)
    zes_vf_util_engine_exp_t engineUtil1 = {};
    zesVFManagementGetVFEngineUtilizationExp(activeVf, &count, &engineUtil1);
    // Use formula to calculate engine utilization % based on the 2 snapshots above
}

// Demonstrate using setter to switch off Engine telemetry for VF0 and then check if Getter returns INVALID
zesVFManagementSetVFTelemetryModeExp(activeVf,  ZES_VF_INFO_ENGINE, false);
ze_result_t res = zesVFManagementGetVFEngineUtilizationExp(activeVf, &count, &engineUtil0);
if (res != ZES_RESULT_SUCCESS) {
    printf("Engine utilization successfully disabled for VF");
}