FreeBSD Manual Pages
CXGBE(4) Kernel Interfaces Manual CXGBE(4) NAME cxgbe -- Chelsio T7, T6, T5, and T4 based 1Gb to 400Gb Ethernet 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): t7fw_cfg_load="YES" t6fw_cfg_load="YES" t5fw_cfg_load="YES" t4fw_cfg_load="YES" if_cxgbe_load="YES" DESCRIPTION The cxgbe driver provides support for PCI Express Ethernet adapters based on the Chelsio Terminator 7, Terminator 6, Terminator 5, and Terminator 4 ASICs (T7, T6, T5, and T4). The driver supports Jumbo Frames, Transmit/Re- ceive checksum offload, TCP segmentation offload (TSO), Large Receive Of- fload (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 require- ments, 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 T7 che chnex vche T6 cc t6nex vcc T5 cxl t5nex vcxl T4 cxgbe t4nex vcxgbe 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 re- mainder 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 400Gb, 200Gb, 50Gb, and 10Gb Ethernet adapters based on the T7 ASIC: * Chelsio S71400 * Chelsio S72200 * Chelsio S72200-OCP * Chelsio T72200 * Chelsio T72200-DPU * Chelsio T72200-FH * Chelsio T72200-FH-DPU * Chelsio T72200-OCP * Chelsio S7450-DPU * Chelsio S7450-OCP * Chelsio T71200-iNIC * Chelsio T7250 * Chelsio T7210-BT * Chelsio T7410-BT-OCP 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 in- structs 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 pri- mary 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 values are in microseconds) and the index selects a value from this list. holdoff_timer_idx_ofld applies to queues used for TOE rx. The de- fault value is 1 which means the timer value is 5us. Different in- terfaces can be assigned different values at any time via the dev.<port>.X.holdoff_tmr_idx and dev.<port>.X.holdoff_tmr_idx_ofld sysctls. 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 in- dex 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 as- signed 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 ifcon- fig 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 in- terfaces can be assigned different values via the dev.<port>.X.qsize_txq sysctl. This sysctl works only when the in- terface 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 de- fault value is 1024. Different interfaces can be assigned differ- ent 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 inter- rupts), bit 1 MSI, and bit 2 MSI-X. The default is 7 (all al- lowed). The driver selects the best possible type out of the al- lowed 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 en- ables 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 dri- ver 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 Ether- net frame in the receive buffer. The default value is 0. A value 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 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 conges- tion 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 in- coming 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 set- tings with the link peer. The default is 7 (all three = 1). This tunable establishes the default PAUSE settings for all ports. Set- tings 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 trans- ceiver/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 de- fault autonegotiation settings for all ports. Settings can be dis- played and controlled on a per-port basis via the dev.<port>.X.au- toneg sysctl. 0 disables autonegotiation. 1 enables autonegotia- tion. 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_clus- ter. 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_clus- ter fails. Note that largest_rx_cluster merely establishes a ceil- ing -- 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 hard- ware resources on the card. This tunable is for specialized appli- cations only and should not be used in normal operation. The con- figuration 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 capa- bility. 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 in- terfaces over the internal switch in the ASIC. Note that the cxg- bev(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. Dif- ferent 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 check- sum 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. 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 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. Support for T7 cards first appeared in FreeBSD 15.0. AUTHORS The cxgbe driver was written by Navdeep Parhar <np@FreeBSD.org>. FreeBSD ports 15.quarterly December 17, 2025 CXGBE(4)
NAME | SYNOPSIS | DESCRIPTION | HARDWARE | LOADER TUNABLES | SUPPORT | SEE ALSO | HISTORY | AUTHORS
Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=cxgbe&sektion=4&manpath=FreeBSD+15.1-RELEASE+and+Ports.quarterly>