VMX(4)                 FreeBSD Kernel Interfaces Manual                 VMX(4)

NAME
     vmx - VMware VMXNET3 Virtual Interface Controller device

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

           device iflib
           device vmx

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

           if_vmx_load="YES"

DESCRIPTION
     The vmx driver provides support for the VMXNET3 virtual NIC available in
     virtual machines by VMware.  It appears as a simple Ethernet device but
     is actually a virtual network interface to the underlying host operating
     system.

     This driver supports the VMXNET3 driver protocol, as an alternative to
     the emulated le(4), em(4) interfaces also available in the VMware
     environment.  The vmx driver is optimized for the virtual machine, it can
     provide advanced capabilities depending on the underlying host operating
     system and the physical network interface controller of the host.  The
     vmx driver supports features like multiqueue support, IPv6 checksum
     offloading, MSI/MSI-X support and hardware VLAN tagging in VMware's VLAN
     Guest Tagging (VGT) mode.

     The vmx driver supports VMXNET3 VMware virtual NICs provided by the
     virtual machine hardware version 7 or newer, as provided by the following
     products:

           •   VMware ESX/ESXi 4.0 and newer
           •   VMware Server 2.0 and newer
           •   VMware Workstation 6.5 and newer
           •   VMware Fusion 2.0 and newer

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

MULTIPLE QUEUES
     The vmx driver supports multiple transmit and receive queues.  Multiple
     queues are only supported by certain VMware products, such as ESXi.  The
     number of queues allocated depends on the presence of MSI-X, the number
     of configured CPUs, and the tunables listed below.  FreeBSD does not
     enable MSI-X support on VMware by default.  The
     hw.pci.honor_msi_blacklist tunable must be disabled to enable MSI-X
     support.

LOADER TUNABLES
     Tunables can be set at the loader(8) prompt before booting the kernel or
     stored in loader.conf(5).

     hw.vmx.txnqueue

     hw.vmx.X.txnqueue
             Maximum number of transmit queues allocated by default by the
             driver.  The default value is 8.  The maximum supported by the
             VMXNET3 virtual NIC is 8.

     hw.vmx.rxnqueue

     hw.vmx.X.rxnqueue
             Maximum number of receive queues allocated by default by the
             driver.  The default value is 8.  The maximum supported by the
             VMXNET3 virtual NIC is 16.

     hw.vmx.txndesc

     hw.vmx.X.txndesc

             Number of transmit descriptors allocated by the driver.  The
             default value is 512.  The value must be a multiple of 32, and
             the maximum is 4096.

     hw.vmx.rxndesc

     hw.vmx.X.rxndesc

             Number of receive descriptors per ring allocated by the driver.
             The default value is 256.  The value must be a multiple of 32,
             and the maximum is 2048.  There are two rings so the actual usage
             is doubled.

EXAMPLES
     The following entry must be added to the VMware configuration file to
     provide the vmx device:

           ethernet0.virtualDev = "vmxnet3"

SEE ALSO
     altq(4), arp(4), em(4), iflib(4), netintro(4), ng_ether(4), le(4),
     vlan(4), ifconfig(8)

AUTHORS
     The vmx driver was ported from OpenBSD and significantly rewritten by
     Bryan Venteicher <bryanv@freebsd.org>.  The OpenBSD driver was written by
     Tsubai Masanari.

FreeBSD 13.1-RELEASE-p6        December 26, 2020       FreeBSD 13.1-RELEASE-p6