1.. SPDX-License-Identifier: GPL-2.0+
2
3=============================================================
4Linux Base Driver for Intel(R) Ethernet Multi-host Controller
5=============================================================
6
7August 20, 2018
8Copyright(c) 2015-2018 Intel Corporation.
9
10Contents
11========
12- Identifying Your Adapter
13- Additional Configurations
14- Performance Tuning
15- Known Issues
16- Support
17
18Identifying Your Adapter
19========================
20The driver in this release is compatible with devices based on the Intel(R)
21Ethernet Multi-host Controller.
22
23For information on how to identify your adapter, and for the latest Intel
24network drivers, refer to the Intel Support website:
25https://www.intel.com/support
26
27
28Flow Control
29------------
30The Intel(R) Ethernet Switch Host Interface Driver does not support Flow
31Control. It will not send pause frames. This may result in dropped frames.
32
33
34Virtual Functions (VFs)
35-----------------------
36Use sysfs to enable VFs.
37Valid Range: 0-64
38
39For example::
40
41    echo $num_vf_enabled > /sys/class/net/$dev/device/sriov_numvfs //enable VFs
42    echo 0 > /sys/class/net/$dev/device/sriov_numvfs //disable VFs
43
44NOTE: Neither the device nor the driver control how VFs are mapped into config
45space. Bus layout will vary by operating system. On operating systems that
46support it, you can check sysfs to find the mapping.
47
48NOTE: When SR-IOV mode is enabled, hardware VLAN filtering and VLAN tag
49stripping/insertion will remain enabled. Please remove the old VLAN filter
50before the new VLAN filter is added. For example::
51
52    ip link set eth0 vf 0 vlan 100	// set vlan 100 for VF 0
53    ip link set eth0 vf 0 vlan 0	// Delete vlan 100
54    ip link set eth0 vf 0 vlan 200	// set a new vlan 200 for VF 0
55
56
57Additional Features and Configurations
58======================================
59
60Jumbo Frames
61------------
62Jumbo Frames support is enabled by changing the Maximum Transmission Unit (MTU)
63to a value larger than the default value of 1500.
64
65Use the ifconfig command to increase the MTU size. For example, enter the
66following where <x> is the interface number::
67
68    ifconfig eth<x> mtu 9000 up
69
70Alternatively, you can use the ip command as follows::
71
72    ip link set mtu 9000 dev eth<x>
73    ip link set up dev eth<x>
74
75This setting is not saved across reboots. The setting change can be made
76permanent by adding 'MTU=9000' to the file:
77
78- For RHEL: /etc/sysconfig/network-scripts/ifcfg-eth<x>
79- For SLES: /etc/sysconfig/network/<config_file>
80
81NOTE: The maximum MTU setting for Jumbo Frames is 15342. This value coincides
82with the maximum Jumbo Frames size of 15364 bytes.
83
84NOTE: This driver will attempt to use multiple page sized buffers to receive
85each jumbo packet. This should help to avoid buffer starvation issues when
86allocating receive packets.
87
88
89Generic Receive Offload, aka GRO
90--------------------------------
91The driver supports the in-kernel software implementation of GRO. GRO has
92shown that by coalescing Rx traffic into larger chunks of data, CPU
93utilization can be significantly reduced when under large Rx load. GRO is an
94evolution of the previously-used LRO interface. GRO is able to coalesce
95other protocols besides TCP. It's also safe to use with configurations that
96are problematic for LRO, namely bridging and iSCSI.
97
98
99
100Supported ethtool Commands and Options for Filtering
101----------------------------------------------------
102-n --show-nfc
103  Retrieves the receive network flow classification configurations.
104
105rx-flow-hash tcp4|udp4|ah4|esp4|sctp4|tcp6|udp6|ah6|esp6|sctp6
106  Retrieves the hash options for the specified network traffic type.
107
108-N --config-nfc
109  Configures the receive network flow classification.
110
111rx-flow-hash tcp4|udp4|ah4|esp4|sctp4|tcp6|udp6|ah6|esp6|sctp6 m|v|t|s|d|f|n|r
112  Configures the hash options for the specified network traffic type.
113
114- udp4: UDP over IPv4
115- udp6: UDP over IPv6
116- f Hash on bytes 0 and 1 of the Layer 4 header of the rx packet.
117- n Hash on bytes 2 and 3 of the Layer 4 header of the rx packet.
118
119
120Known Issues/Troubleshooting
121============================
122
123Enabling SR-IOV in a 64-bit Microsoft Windows Server 2012/R2 guest OS under Linux KVM
124-------------------------------------------------------------------------------------
125KVM Hypervisor/VMM supports direct assignment of a PCIe device to a VM. This
126includes traditional PCIe devices, as well as SR-IOV-capable devices based on
127the Intel Ethernet Controller XL710.
128
129
130Support
131=======
132For general information, go to the Intel support website at:
133https://www.intel.com/support/
134
135If an issue is identified with the released source code on a supported kernel
136with a supported adapter, email the specific information related to the issue
137to intel-wired-lan@lists.osuosl.org.
138