NdisMInvalidateConfigBlock function (ndis.h)

Article
10/21/2021

A miniport driver calls the NdisMInvalidateConfigBlock function to notify NDIS that the data for one or more Virtual Function (VF) configuration blocks has been changed.

Note NdisMInvalidateConfigBlock must only be called by the miniport driver for the network adapter's PCIe Physical Function (PF).

Syntax

void NdisMInvalidateConfigBlock(
  [in] NDIS_HANDLE            NdisMiniportHandle,
  [in] NDIS_SRIOV_FUNCTION_ID VFId,
  [in] ULONGLONG              BlockMask
);

Parameters

[in] NdisMiniportHandle

The network adapter handle that NDIS passed to the MiniportAdapterHandle parameter of MiniportInitializeEx.

[in] VFId

The identifier of the VF for which the device location is returned.

[in] BlockMask

A ULONGLONG value that specifies a bitmask for the first 64 VF configuration blocks. Each bit in the bitmask corresponds to a VF configuration block. If the bit is set to one, the data associated with the corresponding VF configuration block has changed.

Return value

None

Remarks

A VF configuration block is used for backchannel communication between the PF and VF miniport drivers. The IHV can define one or more VF configuration blocks for the device. Each VF configuration block has an IHV-defined format, length, and block ID.

Note Data from each VF configuration block is used only by the PF and VF miniport drivers.

VF configuration data is exchanged between the following drivers:

The VF driver, which runs in the guest operating system. This operating system runs within a Hyper-V child partition.
The PF driver, which runs in the management operating system.
This operating system runs within the Hyper-V parent partition.

In order to handle notifications of invalid VF configuration data, NDIS and the miniport drivers perform the following steps:

In the guest operating system, NDIS issues an I/O control request of IOCTL_VPCI_INVALIDATE_BLOCK request. When this IOCTL is completed, NDIS is notified that VF configuration data has changed.
In the management operating system, the following steps occur:
1. The PF miniport driver calls the NdisMInvalidateConfigBlock function to notify NDIS that VF configuration data has changed and is no longer valid.
2. NDIS signals the virtualization stack, which runs in the management operating system, about the change to VF configuration block data. The virtualization stack caches the BlockMask parameter data.
  Note Each time that the PF miniport driver calls NdisMInvalidateConfigBlock, the virtualization stack ORs the BlockMask parameter data with the current value in its cache.
3. The virtualization stack notifies the virtual PCI (VPCI) driver, which runs in the guest operating system, about the invalidation of VF configuration data. The virtualization stack sends the cached BlockMask parameter data to the VPCI driver.
In the guest operating system, the following steps occur:
1. The VPCI driver saves the cached BlockMask parameter data in the BlockMask member of the VPCI_INVALIDATE_BLOCK_OUTPUT structure that is associated with the IOCTL_VPCI_INVALIDATE_BLOCK request.
2. The VPCI driver successfully completes the IOCTL_VPCI_INVALIDATE_BLOCK request. When this happens, NDIS issues an OID method request of OID_SRIOV_VF_INVALIDATE_CONFIG_BLOCK to the VF miniport driver. An NDIS_SRIOV_VF_INVALIDATE_CONFIG_BLOCK_INFO request is passed along in the OID request. This structure contains the cached BlockMask parameter data.
  NDIS also issues another IOCTL_VPCI_INVALIDATE_BLOCK request to handle successive notifications of changes to VF configuration data.
3. When the VF driver handles the OID_SRIOV_VF_INVALIDATE_CONFIG_BLOCK request, it reads data from the specified VF configuration blocks.

For more information about backchannel communication within the single root I/O virtualization (SR-IOV) interface, see SR-IOV PF/VF Backchannel Communication.

For more information about the SR-IOV interface, see Overview of Single Root I/O Virtualization (SR-IOV).

Requirements

Requirement	Value
Minimum supported client	None supported,Supported in NDIS 6.30 and later.
Minimum supported server	Windows Server 2012
Target Platform	Universal
Header	ndis.h (include Ndis.h)
Library	Ndis.lib
IRQL	<= DISPATCH_LEVEL