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VMQ Standard INF Entries

The following standardized INF keywords are defined to enable or disable support for the virtual machine queue (VMQ) features of miniport adapters.

*VMQ

A value that describes whether the device has enabled or disabled the virtual machine queue (VMQ) feature.

*VMQLookaheadSplit

A value that describes whether the device has enabled or disabled the ability to split receive buffers into lookahead and post-lookahead buffers. The miniport driver reports this capability with the NDIS_RECEIVE_FILTER_LOOKAHEAD_SPLIT_SUPPORTED flag in the SupportedQueueProperties member of the NDIS_RECEIVE_FILTER_CAPABILITIES structure. For more information about this feature, see Shared Memory in Receive Buffers.

*VMQVlanFiltering

A value that describes whether the device has enabled or disabled the ability to filter network packets using the VLAN identifier in the media access control (MAC) header. The miniport driver reports this capability with the NDIS_RECEIVE_FILTER_MAC_HEADER_VLAN_ID_SUPPORTED flag in SupportedMacHeaderFields member of the NDIS_RECEIVE_FILTER_CAPABILITIES structure.

*RssOrVmqPreference

A hidden keyword value that must not be specified in the INF file and is not displayed in the user interface. See the explanation after the table.

The columns in the table at the end of this topic describe the following attributes for enumeration keywords:

SubkeyName

The name of the keyword that you must specify in the INF file and that appears in the registry.

ParamDesc

The display text that is associated with SubkeyName.

Value

The enumeration integer value that is associated with each option in the list. This value is stored in NDI\params\ SubkeyName\Value.

EnumDesc

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

The following table describes the possible INF entries for the VMQ keywords.

SubkeyNameParamDescValueEnumDesc

*VMQ

Virtual Machine Queues

0

Disabled

1 (Default)

Enabled

*VMQLookaheadSplit

VMQ Lookahead Split

0

Disabled

1 (Default)

Enabled

1 (Default)

Enabled

*RssOrVmqPreference

Note: ParamDesc and EnumDesc are not applicable for INF files or a user interface. See the explanation after the table.

0 (Default)

Note: Report RSS capabilities

1

Note: Report VMQ capabilities

*RssOrVmqPreference

Note: ParamDesc and EnumDesc are not applicable for INF files or a user interface. See the explanation after the table.

0 (Default)

Note: Report RSS capabilities

1

Note: Report VMQ capabilities

 

Some drivers that support VMQ and RSS cannot use these features simultaneously. Such drivers cannot switch between RSS support and VMQ support without reinitializing the driver. The operating system uses the RSS feature when the NIC is bound to the TCP/IP stack, or the VMQ feature when the NIC is bound to the Hyper-V virtual switch driver. Because the NIC is not disabled and then re-enabled when it is unbound from the TCP/IP stack and bound to the Hyper-V driver (or the reverse), it is not possible for such NICs to switch between RSS and VMQ automatically.

A miniport driver that supports RSS and VMQ simultaneously reads the *RSS and *VMQ keywords and it reports the current RSS and VMQ capabilities based on those keyword settings. Such a driver never uses the *RssOrVmqPreference keyword.

A miniport driver that does not support RSS and VMQ simultaneously must read a hidden keyword *RssOrVmqPreference before it reports its current capabilities to NDIS. If the value of this keyword is zero, the miniport driver reports that it supports RSS. If the value of this keyword is one, the miniport driver reports that it supports VMQ. The default value is zero.

During miniport adapter initialization, the miniport driver reads the *RssOrVmqPreference registry keyword. If *RssOrVmqPreference is either not present or it is set to zero the miniport driver reports the RSS support that is specified in the *RSS keyword and VMQ is disabled. Otherwise, the miniport driver reports the VMQ support that is specified in the *VMQ keyword and RSS is disabled

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

 

 

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Build date: 2/9/2011