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IOCTL_SRIOV_DETACH IOCTL (pcivirt.h)

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The request indicates that the virtualization stack wants to unregister for Plug and Play events (previously registered through the IOCTL_SRIOV_ATTACH request).

Major code

IRP_MJ_DEVICE_CONTROL

Status block

Irp->IoStatus.Status is set to STATUS_SUCCESS if the request is successful. Otherwise, Status indicates the appropriate error condition as a NTSTATUS code.

Remarks

This IOCTL request is sent by the virtualization stack to the PCI Express SR-IOV Physical Function (PF) driver that exposes GUID_DEVINTERFACE_VIRTUALIZABLE_DEVICE.

From here on, the PF should not expect to receive IOCTL_SRIOV_EVENT_COMPLETE and IOCTL_SRIOV_NOTIFICATION requests.

The driver that must stop waiting for IOCTL_SRIOV_EVENT_COMPLETE. If the driver is currently waiting it should stop waiting and continue processing Plug and Play IRPs.

In this example handling of the IOCTL_SRIOV_DETACH request, the PF driver maintains PnP states in its device context. The deviceContext->PnpRebalancing is set to TRUE, when the driver receives IRP_MN_QUERY_STOP_DEVICE and set to FALSE when it receives IRP_MN_START_DEVICE.

    case IOCTL_SRIOV_DETACH:

        WdfWaitLockAcquire(deviceContext->PnpStateLock, NULL);

        deviceContext->PnpVspAttached = FALSE;

        if (deviceContext->PnpRebalancing != FALSE)
        {
            //
            // Any new client (VSP state machine) will not know about
            // the current rebalance is it should block attach until
            // rebalance is over.
            //

    								deviceContext>PnpSafeToAttach = FALSE;
    								KeClearEvent(&deviceContext>PnpSafeEvent);

        }

        //
        // Unblock the PnP thread if it waiting for an IO control from the
        // client as the client just detached.
        //
        deviceContext->PnpEventStatus = STATUS_SUCCESS;
        KeSetEvent(&deviceContext->PnpUnblockEvent, IO_NO_INCREMENT, FALSE);

        WdfWaitLockRelease(deviceContext->PnpStateLock);

        status = STATUS_SUCCESS;
        break;

Requirements

Requirement Value
Header pcivirt.h
IRQL PASSIVE_LEVEL

See also

WdfIoTargetSendInternalIoctlSynchronously

WdfIoTargetSendInternalIoctlOthersSynchronously

Creating IOCTL Requests in Drivers

IOCTL_SRIOV_ATTACH

WdfIoTargetSendIoctlSynchronously