Issue 11
© Solarflare Communications 2014
144
Solarflare Server Adapter
User Guide
Virtual Machine Queue
Solarflare adapters support VMQ to offload the classification and delivery of network traffic
destined for
Hyper-V
virtual machines to the network adapter thereby reducing the CPU load on
Hyper-V hosts.
Windows Server 2008
R2 allows the administrator user to statically configure the number of CPUs
available to process interrupts for VMQ. Interrupts are spread across the specified cores, however
the static configuration does not provide best performance when the network load varies over time.
Dynamic VMQ, supported in Windows Server 2012 and later, will dynamically distribute received
network traffic across available CPUs while adjusting for network load by, if necessary, bringing in
more processors or releasing processors under light load conditions.
VMQ supports the following features:
• Classification of received network traffic in hardware by using the destination MAC address (and
optionally also the VLAN identifier) to route packets to different receive queues dedicated to
each virtual machine.
• Can use the network adapter to directly transfer received network traffic to a virtual machine’s
shared memory avoiding a potential software-based copy from the Hyper-V host to the virtual
machine.
• Scaling to multiple processors by processing network traffic destined for different virtual
machines on different processors.
Table 35: VMQ Mode Options
Enabled
VMQ is enabled by default.
Enabled (no VLAN filtering)
VMQ uses the VLAN identifier from the
Ethernet MAC header for filtering traffic to
the intended Hyper-V virtual machine.
VMQ VLAN filtering is enabled by default.
When this option is disabled only the
destination MAC address is used for
filtering.
Enabled (MAC address filtering)
VMQ uses the Ethernet MAC header for
filtering traffic to the intended Hyper-V
virtual machine. VMQ VLAN filtering is
enabled by default.
Disabled
VMQ is disabled.