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diff --git a/doc/guides/nics/vmxnet3.rst b/doc/guides/nics/vmxnet3.rst new file mode 100644 index 00000000..e919088d --- /dev/null +++ b/doc/guides/nics/vmxnet3.rst @@ -0,0 +1,197 @@ +.. BSD LICENSE + Copyright(c) 2010-2014 Intel Corporation. All rights reserved. + All rights reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions + are met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in + the documentation and/or other materials provided with the + distribution. + * Neither the name of Intel Corporation nor the names of its + contributors may be used to endorse or promote products derived + from this software without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +Poll Mode Driver for Paravirtual VMXNET3 NIC +============================================ + +The VMXNET3 adapter is the next generation of a paravirtualized NIC, introduced by VMware* ESXi. +It is designed for performance and is not related to VMXNET or VMXENET2. +It offers all the features available in VMXNET2, and adds several new features such as, +multi-queue support (also known as Receive Side Scaling, RSS), +IPv6 offloads, and MSI/MSI-X interrupt delivery. +Because operating system vendors do not provide built-in drivers for this card, +VMware Tools must be installed to have a driver for the VMXNET3 network adapter available. +One can use the same device in a DPDK application with VMXNET3 PMD introduced in DPDK API. + +Currently, the driver provides basic support for using the device in a DPDK application running on a guest OS. +Optimization is needed on the backend, that is, the VMware* ESXi vmkernel switch, to achieve optimal performance end-to-end. + +In this chapter, two setups with the use of the VMXNET3 PMD are demonstrated: + +#. Vmxnet3 with a native NIC connected to a vSwitch + +#. Vmxnet3 chaining VMs connected to a vSwitch + +VMXNET3 Implementation in the DPDK +---------------------------------- + +For details on the VMXNET3 device, refer to the VMXNET3 driver's vmxnet3 directory and support manual from VMware*. + +For performance details, refer to the following link from VMware: + +`http://www.vmware.com/pdf/vsp_4_vmxnet3_perf.pdf <http://www.vmware.com/pdf/vsp_4_vmxnet3_perf.pdf>`_ + +As a PMD, the VMXNET3 driver provides the packet reception and transmission callbacks, vmxnet3_recv_pkts and vmxnet3_xmit_pkts. +It does not support scattered packet reception as part of vmxnet3_recv_pkts and vmxnet3_xmit_pkts. +Also, it does not support scattered packet reception as part of the device operations supported. + +The VMXNET3 PMD handles all the packet buffer memory allocation and resides in guest address space +and it is solely responsible to free that memory when not needed. +The packet buffers and features to be supported are made available to hypervisor via VMXNET3 PCI configuration space BARs. +During RX/TX, the packet buffers are exchanged by their GPAs, +and the hypervisor loads the buffers with packets in the RX case and sends packets to vSwitch in the TX case. + +The VMXNET3 PMD is compiled with vmxnet3 device headers. +The interface is similar to that of the other PMDs available in the DPDK API. +The driver pre-allocates the packet buffers and loads the command ring descriptors in advance. +The hypervisor fills those packet buffers on packet arrival and write completion ring descriptors, +which are eventually pulled by the PMD. +After reception, the DPDK application frees the descriptors and loads new packet buffers for the coming packets. +The interrupts are disabled and there is no notification required. +This keeps performance up on the RX side, even though the device provides a notification feature. + +In the transmit routine, the DPDK application fills packet buffer pointers in the descriptors of the command ring +and notifies the hypervisor. +In response the hypervisor takes packets and passes them to the vSwitch. It writes into the completion descriptors ring. +The rings are read by the PMD in the next transmit routine call and the buffers and descriptors are freed from memory. + +Features and Limitations of VMXNET3 PMD +--------------------------------------- + +In release 1.6.0, the VMXNET3 PMD provides the basic functionality of packet reception and transmission. +There are several options available for filtering packets at VMXNET3 device level including: + +#. MAC Address based filtering: + + * Unicast, Broadcast, All Multicast modes - SUPPORTED BY DEFAULT + + * Multicast with Multicast Filter table - NOT SUPPORTED + + * Promiscuous mode - SUPPORTED + + * RSS based load balancing between queues - SUPPORTED + +#. VLAN filtering: + + * VLAN tag based filtering without load balancing - SUPPORTED + +.. note:: + + + * Release 1.6.0 does not support separate headers and body receive cmd_ring and hence, + multiple segment buffers are not supported. + Only cmd_ring_0 is used for packet buffers, one for each descriptor. + + * Receive and transmit of scattered packets is not supported. + + * Multicast with Multicast Filter table is not supported. + +Prerequisites +------------- + +The following prerequisites apply: + +* Before starting a VM, a VMXNET3 interface to a VM through VMware vSphere Client must be assigned. + This is shown in the figure below. + +.. _figure_vmxnet3_int: + +.. figure:: img/vmxnet3_int.* + + Assigning a VMXNET3 interface to a VM using VMware vSphere Client + +.. note:: + + Depending on the Virtual Machine type, the VMware vSphere Client shows Ethernet adaptors while adding an Ethernet device. + Ensure that the VM type used offers a VMXNET3 device. Refer to the VMware documentation for a listed of VMs. + +.. note:: + + Follow the *DPDK Getting Started Guide* to setup the basic DPDK environment. + +.. note:: + + Follow the *DPDK Sample Application's User Guide*, L2 Forwarding/L3 Forwarding and + TestPMD for instructions on how to run a DPDK application using an assigned VMXNET3 device. + +VMXNET3 with a Native NIC Connected to a vSwitch +------------------------------------------------ + +This section describes an example setup for Phy-vSwitch-VM-Phy communication. + +.. _figure_vswitch_vm: + +.. figure:: img/vswitch_vm.* + + VMXNET3 with a Native NIC Connected to a vSwitch + +.. note:: + + Other instructions on preparing to use DPDK such as, hugepage enabling, uio port binding are not listed here. + Please refer to *DPDK Getting Started Guide and DPDK Sample Application's User Guide* for detailed instructions. + +The packet reception and transmission flow path is:: + + Packet generator -> 82576 + -> VMware ESXi vSwitch + -> VMXNET3 device + -> Guest VM VMXNET3 port 0 rx burst + -> Guest VM 82599 VF port 0 tx burst + -> 82599 VF + -> Packet generator + +VMXNET3 Chaining VMs Connected to a vSwitch +------------------------------------------- + +The following figure shows an example VM-to-VM communication over a Phy-VM-vSwitch-VM-Phy communication channel. + +.. _figure_vm_vm_comms: + +.. figure:: img/vm_vm_comms.* + + VMXNET3 Chaining VMs Connected to a vSwitch + +.. note:: + + When using the L2 Forwarding or L3 Forwarding applications, + a destination MAC address needs to be written in packets to hit the other VM's VMXNET3 interface. + +In this example, the packet flow path is:: + + Packet generator -> 82599 VF + -> Guest VM 82599 port 0 rx burst + -> Guest VM VMXNET3 port 1 tx burst + -> VMXNET3 device + -> VMware ESXi vSwitch + -> VMXNET3 device + -> Guest VM VMXNET3 port 0 rx burst + -> Guest VM 82599 VF port 1 tx burst + -> 82599 VF + -> Packet generator |