Standardized INF Keywords for SR-IOV

This topic describes the standardized INF keywords for the single root I/O virtualization (SR-IOV) interface. These keywords apply to the INF file for the miniport driver of the PCI Express (PCIe) Physical Function (PF) of an SR-IOV network adapter.

The SR-IOV INF keywords are described in the following sections:

Standardized INF Keywords for the Enabling or Disabling SR-IOV Support

Standardized INF Keywords for Configuration of the Default NIC Switch

Standardized INF Keywords for Enabling or Disabling SR-IOV Support

Standardized INF keywords are defined to enable or disable support for the SR-IOV features of a network adapter.

*SRIOV
A value that describes whether the device has enabled or disabled the SR-IOV feature.

After the driver is installed, administrators can update the *SRIOV keyword value in the Advanced property page for the network adapter. For more information about advanced properties, see Specifying Configuration Parameters for the Advanced Properties Page.

Note The miniport driver is automatically restarted after a change is made in the Advanced property page for the adapter.

*SriovPreferred
A value that defines whether SR-IOV capabilities should be enabled instead of virtual machine queue (VMQ) or receive side scaling (RSS) capabilities.

This is a hidden keyword value that must not be specified in the INF file and is not displayed in Advanced property page for the network adapter.

For more information about how to interpret SR-IOV, VMQ, and RSS keywords, see Handling SR-IOV, VMQ, and RSS Standardized INF Keywords.

The SR-IOV standardized INF keywords are enumeration keywords and are described in the following table. The columns in this table describe the following attributes for an enumeration keyword:

SubkeyName
The name of the keyword that you must specify in the INF file. This name also appears in the registry under the NDI\params\ key for the network adapter.

ParamDesc
The display text that is associated with theSubkeyName keyword.

Note The independent hardware vendor (IHV) can define any descriptive text for the SubkeyName.

Value
The enumeration integer value that is associated with each SubkeyName keyword in the list.

EnumDesc
The display text that is associated with each value that appears in the menu.

SubkeyName ParamDesc Value EnumDesc

SRIOV

SR-IOV

0

Disabled

1 (Default)

Enabled

SriovPreferred

The ParamDesc and EnumDesc entries for this subkey cannot be used in either INF files or a user interface.

0 (Default)

Report RSS or VMQ capabilities based on the VmqOrRssPreferrence keyword. Do not report SR-IOV capabilities,

For more information about the VmqOrRssPreferrence keyword, see Standardized INF Keywords for VMQ.

1

Report SR-IOV capabilities.

For more information about standardized INF keywords, see Standardized INF Keywords for Network Devices.

Standardized INF Keywords for Configuration of the Default NIC Switch

Starting with Windows Server 2012, the SR-IOV interface supports only one NIC switch on the network adapter. This switch is known as the default NIC switch, and is referenced by the NDIS_DEFAULT_SWITCH_ID identifier.

The INF file for the PF miniport driver must specify the configuration of the default NIC switch on the SR-IOV network adapter. This allows the network installer to copy the default switch configuration information from the INF to the miniport registry configuration under the subkey for the default switch (NDI\params\NicSwitches\0).

These keywords are not displayed in the Advanced property page for the network adapter and cannot be configured by the user. These keywords are specified by using the AddReg directive in the DDInstall section of the INF file. Each keyword is specified by a separate AddReg directive.

The following table describes the INF keywords for the default NIC switch configuration of the SR-IOV network adapter. The columns in this table describe the following attributes for these keywords:

SubkeyName
The name of the keyword that you must specify in the INF file. This name also appears in the registry under the NDI\params\NicSwitches\0 key for the network adapter.

Data value
The value that is associated with the SubkeyName keyword.

Data type
The type of the data value.

SubkeyName Data value Data type Notes

Flags

0

REG_DWORD

The keyword must be assigned this value.

SwitchType

1

REG_DWORD

The keyword must be assigned this value.

SwitchId

0

REG_DWORD

The keyword must be assigned this value.

SwitchName

“Default Switch”

REG_SZ

The keyword must be assigned this value.

*NumVFs

(0-n),

REG_DWORD

n is the maximum number of PCIe Virtual Functions (VFs) that are supported by the SR-IOV network adapter.

Note This registry key defines the maximum number of VFs that the network adapter supports. When the miniport driver calls NdisMSetMiniportAttributes, it can advertise less than this value depending on the available hardware resources on the network adapter. For more information, see Determining NIC Switch Capabilities.

The following is an example of AddReg directives for the default NIC switch configuration of an SR-IOV network adapter:

HKR, NicSwitches\0, *SwitchId,   0x00010001, 0
HKR, NicSwitches\0, *SwitchName, 0x00000000, “Default Switch”

For more information about the syntax of the AddReg directive, see INF AddReg Directive.

For more information about the default NIC switch, see NIC Switches.