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NAME

     cxgbev — Chelsio T4-, T5-, and T6-based 100Gb, 40Gb, 25Gb, 10Gb, and 1Gb Ethernet VF driver

SYNOPSIS

     To compile this driver into the kernel, place the following lines in your kernel
     configuration file:

           device cxgbe
           device cxgbev

     To load the driver as a module at boot time, place the following line in loader.conf(5):

           if_cxgbev_load="YES"

DESCRIPTION

     The cxgbev driver provides support for Virtual Functions on 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 cxgbev driver uses different names for devices based on the associated ASIC:

           ASIC    Port Name    Parent Device
           T4      cxgbev       t4vf
           T5      cxlv         t5vf
           T6      ccv          t6vf

     Loader tunables with the hw.cxgbe prefix apply to VFs from all cards.  The Physical Function
     driver for Chelsio Terminator adapters shares these tunables.  The driver provides sysctl
     MIBs for both ports and parent devices using the names above.  For example, a T5 VF provides
     port MIBs under dev.cxlv and parent device MIBs under dev.t5vf.  References to sysctl MIBs
     in the remainder of this page use dev.<port> for port MIBs and dev.<nexus> for parent device
     MIBs.

     For more information on configuring this device, see ifconfig(8).

HARDWARE

     The cxgbev driver supports Virtual Functions on 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 cxgbev driver supports Virtual Functions on 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 cxgbev driver supports Virtual Functions on 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).

     hw.cxgbe.ntxq
             Number of 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 rx queues used for a port.  The default is 8 or the number of CPU cores in
             the system, whichever is less.

     hw.cxgbe.holdoff_timer_idx
             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
             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.  Note that Virtual Functions do not support INTx
             interrupts and fail to attach if neither MSI nor MSI-X are enabled.

     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.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.

     Certain settings and resources for Virtual Functions are dictated by the parent Physical
     Function driver.  For example, the Physical Function driver limits the number of queues
     available to a Virtual Function.  Some of these limits can be adjusted in the firmware
     configuration file used with the Physical Function driver.

     The PAUSE settings on the port of a Virtual Function are inherited from the settings of the
     same port on the Physical Function.  Virtual Functions cannot modify the setting and track
     changes made to the associated port's setting by the Physical Function driver.

     Receive queues on a Virtual Function always drop packets in response to congestion
     (equivalent to setting hw.cxgbe.cong_drop to 1).

     The VF driver currently depends on the PF driver.  As a result, loading the VF driver also
     loads the PF driver as a dependency.

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), cxgbe(4), netintro(4), ng_ether(4), ifconfig(8)

HISTORY

     The cxgbev device driver first appeared in FreeBSD 11.1 and FreeBSD 11.1.

AUTHORS

     The cxgbev driver was written by Navdeep Parhar <np@FreeBSD.org> and John Baldwin
     <jhb@FreeBSD.org>.