Dell Mellanox Family of Adapters - Manual (Page 48)

Driver Installation and Configuration Rev 1.1
Mellanox Technologies 48
• ip link set dev eth2 vf 2 qos 3 - sets VST mode for VF #2 belonging to PF eth2,
with qos = 3
• ip link set dev eth2 vf 2 4095 - sets mode for VF 2 back to VGT
4.2.7.7.2 Additional Ethernet VF Configuration Options
• Guest MAC configuration
By default, guest MAC addresses are configured to be all zeroes. In the mlnx_ofed guest driver,
if a guest sees a zero MAC, it generates a random MAC address for itself. If the administrator wishes
the guest to always start up with the same MAC, he/she should configure guest MACs before the
guest driver comes up.
The guest MAC may be configured by using:
For legacy guests, which do not generate random MACs, the adminstrator should always configure
their MAC addresses via ip link, as above.
• Spoof checking
Spoof checking is currently available only on upstream kernels newer than 3.1.
4.2.7.7.3 RoCE Support
RoCE is supported on Virtual Functions and VLANs may be used with it. For RoCE, the hyper-
visor GID table size is of 16 entries while the VFs share the remaining 112 entries. When the
number of VFs is larger than 56 entries, some of them will have GID table with only a single
entry which is inadequate if VF's Ethernet device is assigned with an IP address.
When setting num_vfs in mlx4_core module parameter it is important to check that the number
of the assigned IP addresses per VF does not exceed the limit for GID table size.
4.2.8 Ethtool
ethtool is a standard Linux utility for controlling network drivers and hardware, particularly for
wired Ethernet devices. It can be used to:
• Get identification and diagnostic information
• Get extended device statistics
• Control speed, duplex, autonegotiation and flow control for Ethernet devices
• Control checksum offload and other hardware offload features
• Control DMA ring sizes and interrupt moderation
ip link set dev <PF device> vf <NUM> mac <LLADDR>
ip link set dev <PF device> vf <NUM> spoofchk [on | off]