Provided by: freebsd-manpages_11.1-3_all 
NAME
cxgbe — Chelsio T4-, T5-, and T6-based 100Gb, 40Gb, 25Gb, 10Gb, and 1Gb Ethernet adapter driver
SYNOPSIS
To compile this driver into the kernel, place the following lines in your kernel configuration file:
device cxgbe
To load the driver as a module at boot time, place the following lines in loader.conf(5):
t4fw_cfg_load="YES"
t5fw_cfg_load="YES"
t6fw_cfg_load="YES"
if_cxgbe_load="YES"
DESCRIPTION
The cxgbe driver provides support for PCI Express Ethernet adapters based on the Chelsio Terminator 4,
Terminator 5, and Terminator 6 ASICs (T4, T5, and T6). The driver supports Jumbo Frames,
Transmit/Receive checksum offload, TCP segmentation offload (TSO), Large Receive Offload (LRO), VLAN tag
insertion/extraction, VLAN checksum offload, VLAN TSO, and Receive Side Steering (RSS). For further
hardware information and questions related to hardware requirements, see http://www.chelsio.com/.
The cxgbe driver uses different names for devices based on the associated ASIC:
ASIC Port Name Parent Device Virtual Interface
T4 cxgbe t4nex vcxgbe
T5 cxl t5nex vcxl
T6 cc t6nex vcc
Loader tunables with the hw.cxgbe prefix apply to all cards. The driver provides sysctl MIBs for both
ports and parent devices using the names above. For example, a T5 adapter provides port MIBs under
dev.cxl and adapter-wide MIBs under dev.t5nex. References to sysctl MIBs in the remainder of this page
use dev.<port> for port MIBs and dev.<nexus> for adapter-wide MIBs.
For more information on configuring this device, see ifconfig(8).
HARDWARE
The cxgbe driver supports 100Gb and 25Gb Ethernet adapters based on the T6 ASIC:
• Chelsio T6225-CR
• Chelsio T6225-SO-CR
• Chelsio T62100-LP-CR
• Chelsio T62100-SO-CR
• Chelsio T62100-CR
The cxgbe driver supports 40Gb, 10Gb and 1Gb Ethernet adapters based on the T5 ASIC:
• Chelsio T580-CR
• Chelsio T580-LP-CR
• Chelsio T580-LP-SO-CR
• Chelsio T560-CR
• Chelsio T540-CR
• Chelsio T540-LP-CR
• Chelsio T522-CR
• Chelsio T520-LL-CR
• Chelsio T520-CR
• Chelsio T520-SO
• Chelsio T520-BT
• Chelsio T504-BT
The cxgbe driver supports 10Gb and 1Gb Ethernet adapters based on the T4 ASIC:
• Chelsio T420-CR
• Chelsio T422-CR
• Chelsio T440-CR
• Chelsio T420-BCH
• Chelsio T440-BCH
• Chelsio T440-CH
• Chelsio T420-SO
• Chelsio T420-CX
• Chelsio T420-BT
• Chelsio T404-BT
LOADER TUNABLES
Tunables can be set at the loader(8) prompt before booting the kernel or stored in loader.conf(5). There
are multiple tunables that control the number of queues of various types. A negative value for such a
tunable instructs the driver to create up to that many queues if there are enough CPU cores available.
hw.cxgbe.ntxq10g
Number of tx queues used for a 10Gb or higher-speed port. The default is 16 or the number of CPU
cores in the system, whichever is less.
hw.cxgbe.nrxq10g
Number of rx queues used for a 10Gb or higher-speed port. The default is 8 or the number of CPU
cores in the system, whichever is less.
hw.cxgbe.ntxq1g
Number of tx queues used for a 1Gb port. The default is 4 or the number of CPU cores in the
system, whichever is less.
hw.cxgbe.nrxq1g
Number of rx queues used for a 1Gb port. The default is 2 or the number of CPU cores in the
system, whichever is less.
hw.cxgbe.nofldtxq10g
Number of TOE tx queues used for a 10Gb or higher-speed port. The default is 8 or the number of
CPU cores in the system, whichever is less.
hw.cxgbe.nofldrxq10g
Number of TOE rx queues used for a 10Gb or higher-speed port. The default is 2 or the number of
CPU cores in the system, whichever is less.
hw.cxgbe.nofldtxq1g
Number of TOE tx queues used for a 1Gb port. The default is 2 or the number of CPU cores in the
system, whichever is less.
hw.cxgbe.nofldrxq1g
Number of TOE rx queues used for a 1Gb port. The default is 1.
hw.cxgbe.num_vis
Number of virtual interfaces (VIs) created for each port. Each virtual interface creates a
separate network interface. The first virtual interface on each port is required and represents
the primary network interface on the port. Additional virtual interfaces on a port are named
using the Virtual Interface name from the table above. Additional virtual interfaces use a
single pair of queues for rx and tx as well an additional pair of queues for TOE rx and tx. The
default is 1.
hw.cxgbe.holdoff_timer_idx_10G
hw.cxgbe.holdoff_timer_idx_1G
Timer index value used to delay interrupts. The holdoff timer list has the values 1, 5, 10, 50,
100, and 200 by default (all values are in microseconds) and the index selects a value from this
list. The default value is 1 which means the timer value is 5us. Different interfaces can be
assigned different values at any time via the dev.<port>.X.holdoff_tmr_idx sysctl.
hw.cxgbe.holdoff_pktc_idx_10G
hw.cxgbe.holdoff_pktc_idx_1G
Packet-count index value used to delay interrupts. The packet-count list has the values 1, 8,
16, and 32 by default, and the index selects a value from this list. The default value is -1
which means packet counting is disabled and interrupts are generated based solely on the holdoff
timer value. Different interfaces can be assigned different values via the
dev.<port>.X.holdoff_pktc_idx sysctl. This sysctl works only when the interface has never been
marked up (as done by ifconfig up).
hw.cxgbe.qsize_txq
Number of entries in a transmit queue's descriptor ring. A buf_ring of the same size is also
allocated for additional software queuing. See ifnet(9). The default value is 1024. Different
interfaces can be assigned different values via the dev.<port>.X.qsize_txq sysctl. This sysctl
works only when the interface has never been marked up (as done by ifconfig up).
hw.cxgbe.qsize_rxq
Number of entries in a receive queue's descriptor ring. The default value is 1024. Different
interfaces can be assigned different values via the dev.<port>.X.qsize_rxq sysctl. This sysctl
works only when the interface has never been marked up (as done by ifconfig up).
hw.cxgbe.interrupt_types
Permitted interrupt types. Bit 0 represents INTx (line interrupts), bit 1 MSI, and bit 2 MSI-X.
The default is 7 (all allowed). The driver selects the best possible type out of the allowed
types.
hw.cxgbe.fw_install
0 prohibits the driver from installing a firmware on the card. 1 allows the driver to install a
new firmware if internal driver heuristics indicate that the new firmware is preferable to the
one already on the card. 2 instructs the driver to always install the new firmware on the card
as long as it is compatible with the driver and is a different version than the one already on
the card. The default is 1.
hw.cxgbe.fl_pktshift
Number of padding bytes inserted before the beginning of an Ethernet frame in the receive buffer.
The default value of 2 ensures that the Ethernet payload (usually the IP header) is at a 4 byte
aligned address. 0-7 are all valid values.
hw.cxgbe.fl_pad
A non-zero value ensures that writes from the hardware to a receive buffer are padded up to the
specified boundary. The default is -1 which lets the driver pick a pad boundary. 0 disables
trailer padding completely.
hw.cxgbe.cong_drop
Controls the hardware response to congestion. -1 disables congestion feedback and is not
recommended. 0 instructs the hardware to backpressure its pipeline on congestion. This usually
results in the port emitting PAUSE frames. 1 instructs the hardware to drop frames destined for
congested queues.
hw.cxgbe.pause_settings
PAUSE frame settings. Bit 0 is rx_pause, bit 1 is tx_pause. rx_pause = 1 instructs the hardware
to heed incoming PAUSE frames, 0 instructs it to ignore them. tx_pause = 1 allows the hardware
to emit PAUSE frames when its receive FIFO reaches a high threshold, 0 prohibits the hardware
from emitting PAUSE frames. The default is 3 (both rx_pause and tx_pause = 1). This tunable
establishes the default PAUSE settings for all ports. Settings can be displayed and controlled
on a per-port basis via the dev.<port>.X.pause_settings sysctl.
hw.cxgbe.fec
FEC (Forward Error Correction) settings. 0 diables FEC. Bit 0 enables RS FEC, bit 1 enables
BASE-R RS, bit 3 is reserved. The default is -1 which lets the driver pick a value. This
tunable establishes the default FEC settings for all ports. Settings can be displayed and
controlled on a per-port basis via the dev.<port>.X.fec sysctl.
hw.cxgbe.autoneg
Link autonegotiation settings. This tunable establishes the default autonegotiation settings for
all ports. Settings can be displayed and controlled on a per-port basis via the
dev.<port>.X.autoneg sysctl. 0 disables autonegotiation. 1 enables autonegotiation. The
default is -1 which lets the driver pick a value. dev.<port>.X.autoneg is -1 for port and module
combinations that do not support autonegotiation.
hw.cxgbe.buffer_packing
Allow the hardware to deliver multiple frames in the same receive buffer opportunistically. The
default is -1 which lets the driver decide. 0 or 1 explicitly disable or enable this feature.
hw.cxgbe.allow_mbufs_in_cluster
1 allows the driver to lay down one or more mbufs within the receive buffer opportunistically.
This is the default. 0 prohibits the driver from doing so.
hw.cxgbe.largest_rx_cluster
hw.cxgbe.safest_rx_cluster
Sizes of rx clusters. Each of these must be set to one of the sizes available (usually 2048,
4096, 9216, and 16384) and largest_rx_cluster must be greater than or equal to safest_rx_cluster.
The defaults are 16384 and 4096 respectively. The driver never attempts to allocate a receive
buffer larger than largest_rx_cluster and falls back to allocating buffers of safest_rx_cluster
size if an allocation larger than safest_rx_cluster fails. Note that largest_rx_cluster merely
establishes a ceiling -- the driver is allowed to allocate buffers of smaller sizes.
hw.cxgbe.config_file
Select a pre-packaged device configuration file. A configuration file contains a recipe for
partitioning and configuring the hardware resources on the card. This tunable is for specialized
applications only and should not be used in normal operation. The configuration profile
currently in use is available in the dev.<nexus>.X.cf and dev.<nexus>.X.cfcsum sysctls.
hw.cxgbe.linkcaps_allowed
hw.cxgbe.niccaps_allowed
hw.cxgbe.toecaps_allowed
hw.cxgbe.rdmacaps_allowed
hw.cxgbe.iscsicaps_allowed
hw.cxgbe.fcoecaps_allowed
Disallowing capabilities provides a hint to the driver and firmware to not reserve hardware
resources for that feature. Each of these is a bit field with a bit for each sub-capability
within the capability. This tunable is for specialized applications only and should not be used
in normal operation. The capabilities for which hardware resources have been reserved are listed
in dev.<nexus>.X.*caps sysctls.
SUPPORT
For general information and support, go to the Chelsio support website at: http://www.chelsio.com/.
If an issue is identified with this driver with a supported adapter, email all the specific information
related to the issue to ⟨support@chelsio.com⟩.
SEE ALSO
altq(4), arp(4), cxgb(4), cxgbev(4), netintro(4), ng_ether(4), ifconfig(8)
HISTORY
The cxgbe device driver first appeared in FreeBSD 9.0. Support for T5 cards first appeared in
FreeBSD 9.2 and FreeBSD 10.0. Support for T6 cards first appeared in FreeBSD 11.1 and FreeBSD 12.0.
AUTHORS
The cxgbe driver was written by Navdeep Parhar <np@FreeBSD.org>.
Debian December 22, 2016 CXGBE(4)