CXGBEV(4) FreeBSD Kernel Interfaces Manual CXGBEV(4)
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>.
FreeBSD 13.1-RELEASE-p6 May 9, 2017 FreeBSD 13.1-RELEASE-p6
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