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CXGBE(4) FreeBSD Kernel Interfaces Manual CXGBE(4)
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, VXLAN
checksum offload, VXLAN 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:
o Chelsio T6225-CR
o Chelsio T6225-SO-CR
o Chelsio T62100-LP-CR
o Chelsio T62100-SO-CR
o Chelsio T62100-CR
The cxgbe driver supports 40Gb, 10Gb and 1Gb Ethernet adapters based on
the T5 ASIC:
o Chelsio T522-CR
o Chelsio T520-LL-CR
o Chelsio T520-CR
o Chelsio T520-SO
o Chelsio T520-BT
o Chelsio T504-BT
The cxgbe driver supports 10Gb and 1Gb Ethernet adapters based on the T4
ASIC:
o Chelsio T420-CR
o Chelsio T422-CR
o Chelsio T440-CR
o Chelsio T420-BCH
o Chelsio T440-BCH
o Chelsio T440-CH
o Chelsio T420-SO
o Chelsio T420-CX
o Chelsio T420-BT
o 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.ntxq
Number of NIC tx queues used for a port. The default is 16 or
the number of CPU cores in the system, whichever is less.
hw.cxgbe.nrxq
Number of NIC rx queues used for a port. The default is 8 or the
number of CPU cores in the system, whichever is less.
hw.cxgbe.nofldtxq
Number of TOE tx queues used for a port. The default is 8 or the
number of CPU cores in the system, whichever is less.
hw.cxgbe.nofldrxq
Number of TOE rx queues used for a port. The default is 2 or the
number of CPU cores in the system, whichever is less.
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
hw.cxgbe.holdoff_timer_idx_ofld
Timer index value used to delay interrupts. The holdoff timer
list has the values 1, 5, 10, 50, 100, and 200 by default (all
hw.cxgbe.holdoff_pktc_idx
hw.cxgbe.holdoff_pktc_idx_ofld
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. holdoff_pktc_idx_ofld
applies to queues used for TOE rx. 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 and
dev.<port>.X.holdoff_pktc_idx_ofld sysctls. These sysctls work
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.pcie_relaxed_ordering
PCIe Relaxed Ordering. -1 indicates the driver should determine
whether to enable or disable PCIe RO. 0 disables PCIe RO. 1
enables PCIe RO. 2 indicates the driver should not modify the
PCIe RO setting. The default is -1.
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 is 0. A
value of of 2 would ensure 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
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. 2
instructs the hardware to both backpressure the pipeline and drop
frames.
hw.cxgbe.pause_settings
PAUSE frame settings. Bit 0 is rx_pause, bit 1 is tx_pause, bit
2 is pause_autoneg. 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. pause_autoneg = 1 overrides the rx_pause and
tx_pause bits and instructs the hardware to negotiate PAUSE
settings with the link peer. The default is 7 (all three = 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
Forward Error Correction settings. -1 (default) means driver
should automatically pick a value. 0 disables FEC. Finer
grained control can be achieved by setting individual bits. Bit
0 enables RS FEC, bit 1 enables BASE-R FEC (aka Firecode FEC),
bit 2 enables NO FEC, and bit 6 enables the FEC that is
recommended by the transceiver/cable that is plugged in. These
bits can be set together in any combination. This tunable
establishes the default FEC settings for all ports. Settings can
be controlled on a per-port basis via the
dev.<port>.X.requested_fec sysctl. The FEC in use on the link is
available in dev.<port>.X.link_fec when the link is up.
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.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
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.
hw.cxgbe.tx_vm_wr
Setting this to 1 instructs the driver to use VM work requests to
transmit data. This lets PF interfaces transmit frames to VF
interfaces over the internal switch in the ASIC. Note that the
cxgbev(4) VF driver always uses VM work requests and is not
affected by this tunable. The default value is 0 and should be
changed only if PF and VF interfaces need to communicate with
each other. Different interfaces can be assigned different
values using the dev.<port>.X.tx_vm_wr sysctl when the interface
is administratively down.
hw.cxgbe.attack_filter
Set to 1 to enable the "attack filter". Default is 0. The
attack filter will drop an incoming frame if any of these
conditions is true: src ip/ip6 == dst ip/ip6; tcp and src/dst ip
is not unicast; src/dst ip is loopback (127.x.y.z); src ip6 is
not unicast; src/dst ip6 is loopback (::1/128) or unspecified
(::/128); tcp and src/dst ip6 is mcast (ff00::/8). This facility
is available on T4 and T5 based cards only.
hw.cxgbe.drop_ip_fragments
Set to 1 to drop all incoming IP fragments. Default is 0. Note
that this drops valid frames.
hw.cxgbe.drop_pkts_with_l2_errors
Set to 1 to drop incoming frames with Layer 2 length or checksum
errors. Default is 1.
hw.cxgbe.drop_pkts_with_l3_errors
Set to 1 to drop incoming frames with IP version, length, or
checksum errors. The IP checksum is validated for TCP or UDP
packets only. Default is 0.
hw.cxgbe.drop_pkts_with_l4_errors
Set to 1 to drop incoming frames with Layer 4 (TCP or UDP)
length, checksum, or other errors. Default is 0.
SEE ALSO
arp(4), ccr(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>.
FreeBSD 14.0-RELEASE-p11 November 10, 2022 FreeBSD 14.0-RELEASE-p11