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.\" $FreeBSD: src/share/man/man4/ixgbe.4,v 1.2 2008/06/17 21:14:02 brueffer Exp $
.\"
.Dd December 17, 2017
.Dt IX 4
.Os
.Sh NAME
.Nm ix
.Nd "Intel(R) 10Gb Ethernet driver"
.Sh SYNOPSIS
To compile this driver into the kernel,
place the following line in your
kernel configuration file:
.Bd -ragged -offset indent
.Cd "device ix"
.Ed
.Pp
Alternatively, to load the driver as a
module at boot time, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
if_ix_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
driver provides support for PCI Express 10Gb Ethernet adapters based on
the Intel
82598,
82599,
and
X540
Ethernet controller chips.
The
.Nm
driver supports:
.Pp
.Bl -item -offset indent -compact
.It
Transmit/Receive checksum offload for IP/UDP/TCP.
.\"Jumbo Frames.
.It
Interrupt moderation
.It
TCP segmentation offload (TSO)
.It
Receive side scaling (RSS)
.It
Multiple tranmission queues
.It
Multiple vector MSI-X
.It
VLAN tag stripping and inserting
.El
.Pp
If
.Xr polling 4
or MSI-X is used,
by default,
the
.Nm
driver will try enabling as many reception queues and transmission queues
as are allowed by the number of CPUs in the system.
.Pp
If multiple transmission queues are used,
the round-robin arbitration is performed among the transmission queues.
And if both TSO and multiple tranmission queues are used,
the round-robin arbitration between transmission queues is done at the
TCP segment boundary after the hardware segmentation is performed.
.Pp
82598 supports 16 reception queues and 32 transmission queues.
MSI-X is not enabled due to hardware errata.
Under MSI or legacy interrupt mode,
2 reception queues are enabled for hardware RSS hash
and only 1 transmission queue is enable.
.Pp
82599 and X540 supports 16 reception queues and 64 transmission queues.
MSI-X is enable by default.
However,
due to the number of MSI-X vectors is 64,
at most 16 reception queues and 32 transmission queues will be enabled
under MSI-X mode.
.Pp
The
.Nm
driver supports the following media types:
.Bl -tag -width ".Cm autoselect"
.It Cm autoselect
Enables auto-negotiation for speed and duplex.
.El
.Pp
The
.Nm
driver supports the following media options:
.Bl -tag -width ".Cm forcepause"
.It Cm rxpause
Enable flow control PAUSE reception.
.It Cm txpause
Enable flow control PAUSE transmission.
.It Cm forcepause
Force flow control PAUSE operation as configured by
.Cm rxpause
and
.Cm txpause
media options.
.El
.Pp
For more information on configuring this device, see
.Xr ifconfig 8 .
The
.Nm
driver supports
.Xr polling 4 .
.Sh HARDWARE
The
.Nm
driver supports Gigabit Ethernet adapters based on the Intel
82598,
82599,
and
X540
controller chips:
.Pp
.Bl -bullet -compact
.It
Intel 10 Gigabit AT Server Adapter
.It
Intel 82598EB 10 Gigabit Ethernet Controller
.It
Intel 82599EB 10 Gigabit Ethernet Controller
.It
Intel 82599EN 10 Gigabit Ethernet Controller
.It
Intel 82599ES 10 Gigabit Ethernet Controller
.It
Intel Ethernet Controller X540-AT2
.It
Intel Ethernet Controller X550-AT
.It
Intel Ethernet Controller X550-AT2
.It
Intel Ethernet Controller X550-BT2
.It
Intel Ethernet Connection X557-AT
.It
Intel Ethernet Connection X557-AT2
.It
Intel Ethernet Connection X557-AT4
.It
Intel Ethernet Controller X710-AM2
.It
Intel Ethernet Converged Network Adapter X520-DA1
.It
Intel Ethernet Converged Network Adapter X520-DA2
.It
Intel Ethernet Converged Network Adapter X520-LR1
.It
Intel Ethernet Converged Network Adapter X520-QDA1
.It
Intel Ethernet Converged Network Adapter X520-SR1
.It
Intel Ethernet Converged Network Adapter X520-SR2
.It
Intel Ethernet Converged Network Adapter X540-T1
.It
Intel Ethernet Converged Network Adapter X540-T2
.It
Intel Ethernet Converged Network Adapter X550-T1
.It
Intel Ethernet Converged Network Adapter X550-T2
.It
Intel Ethernet Converged Network Adapter X710-DA2
.It
Intel Ethernet Converged Network Adapter X710-DA4
.El
.Sh TUNABLES
Tunables can be set at the
.Xr loader 8
prompt before booting the kernel or stored in
.Xr loader.conf 5 .
.Em Y
is the device unit number.
.Bl -tag -width ".Va hw.ixY.unsupported_sfp"
.It Va hw.ix.rxd Va hw.ixY.rxd
Number of receive descriptors allocated by the driver.
The default value is 2048.
The minimum is 64,
and the maximum is 4096.
.It Va hw.ix.txd Va hw.ixY.txd
Number of transmit descriptors allocated by the driver.
The default value is 2048.
The minimum is 64,
and the maximum is 4096.
.It Va hw.ix.rxr Va hw.ixY.rxr
This tunable specifies the number of reception queues could be enabled.
Maximum allowed value for these tunables is device specific
and it must be power of 2 aligned.
Setting these tunables to 0 allows the driver to make
as many reception queues ready-for-use as allowed by the number of CPUs.
.It Va hw.ix.txr Va hw.ixY.txr
This tunable specifies the number of transmission queues could be enabled.
Maximum allowed value for these tunables is device specific
and it must be power of 2 aligned.
Setting these tunables to 0 allows the driver to make
as many transmission queues ready-for-use as allowed by the number of CPUs.
.It Va hw.ix.msix.enable Va hw.ixY.msix.enable
By default,
the driver will use MSI-X if it is supported.
This behaviour can be turned off by setting this tunable to 0.
.It Va hw.ix.msi.enable Va hw.ixY.msi.enable
If MSI-X is disabled and MSI is supported,
the driver will use MSI.
This behavior can be turned off by setting this tunable to 0.
.It Va hw.ixY.msi.cpu
If MSI is used,
it specifies the MSI's target CPU.
.It Va hw.ix.unsupported_sfp
By default,
this driver does not allow "unsupported" SFP modules.
This behavior can be changed by setting this tunable to 1.
.It Va hw.ix.flow_ctrl Va hw.ixY.flow_ctrl
The default flow control settings.
Supported values are:
rxpause (only enable PAUSE reception),
txpause (only enable PAUSE transmission),
full (enable PAUSE reception and transmission),
none (disable flow control PAUSE operation),
force-rxpause (force PAUSE reception),
force-txpause (force PAUSE transmission),
force-full (forcefully enable PAUSE reception and transmission),
force-none (forcefully disable flow control PAUSE operation).
Default is none.
.It Va hw.ix.direct_input
By default,
if the
.Xr polling 4
is enabled,
the driver will handle input packets directly,
instead of queuing input packets for further processing.
The direct input packets handling improves performance and
stablize latency.
.El
.Sh MIB Variables
A number of per-interface variables are implemented in the
.Va dev.ix. Ns Em Y
branch of the
.Xr sysctl 3
MIB.
.Bl -tag -width "rxtx_intr_rate"
.It Va rxr
Number of reception queues could be enabled (read-only).
Use the tunable
.Va hw.ix.rxr
or
.Va hw.ixY.rxr
to configure it.
.It Va rxr_inuse
Number of reception queues being used (read-only).
.It Va txr
Number of transmission queues could be enabled (read-only).
Use the tunable
.Va hw.ix.txr
or
.Va hw.ixY.txr
to configure it.
.It Va txr_inuse
Number of transmission queues being used (read-only).
.It Va rxd
Number of descriptors per reception queue (read-only).
Use the tunable
.Va hw.ix.rxd
or
.Va hw.ixY.rxd
to configure it.
.It Va txd
Number of descriptors per transmission queue (read-only).
Use the tunable
.Va hw.ix.txd
or
.Va hw.ixY.txd
to configure it.
.It Va rxtx_intr_rate
If MSI or legacy interrupt is used,
this sysctl controls the highest possible frequency
that interrupt could be generated by the device.
If MSI-X is used,
this sysctl controls the highest possible frequency
that interrupt could be generated by the MSI-X vectors,
which aggregate transmission queue and reception queue procecssing.
It is 8000 by default (125us).
.It Va rx_intr_rate
If MSI-X is used,
this sysctl controls the highest possible frequency
that interrupt could be generated by the MSI-X vectors,
which only process reception queue.
It is 8000 by default (125us).
.It Va tx_intr_rate
If MSI-X is used,
this sysctl controls the highest possible frequency
that interrupt could be generated by the MSI-X vectors,
which only process transmission queue.
It is 6000 by default (~150us).
.It Va sts_intr_rate
If MSI-X is used,
this sysctl controls the highest possible frequency
that interrupt could be generated by the MSI-X vectors,
which only process chip status changes.
It is 8000 by default (125us).
.It Va tx_intr_nsegs
Transmission interrupt is asked to be generated upon every
.Va tx_intr_nsegs
transmission descritors having been setup.
The default value is 1/16 of the number of transmission descriptors per queue.
.It Va tx_wreg_nsegs
The number of transmission descriptors should be setup
before the hardware register is written.
Setting this value too high will have negative effect
on transmission timeliness.
Setting this value too low will hurt overall transmission performance
due to the frequent hardware register writing.
The default value is 8.
.It Va rx_wreg_nsegs
The number of reception descriptors should be setup
before the hardware register is written.
Setting this value too high will make device drop incoming packets.
Setting this value too low will hurt overall reception performance
due to the frequent hardware register writing.
The default value is 32.
.It Va direct_input
See
.Va hw.ix.direct_input .
.Xr polling 4
needs to be turned off and turned on again to make this variable take effect.
.El
.Sh SEE ALSO
.Xr altq 4 ,
.Xr arp 4 ,
.Xr ifmedia 4 ,
.Xr netintro 4 ,
.Xr ng_ether 4 ,
.Xr polling 4 ,
.Xr vlan 4 ,
.Xr ifconfig 8
.Sh HISTORY
The
.Nm
device driver first appeared in
.Dx 3.1 .
.Sh AUTHORS
The
.Nm
driver was written by
.An Intel Corporation Aq Mt freebsdnic@mailbox.intel.com .