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