projects / ceph.git / blame
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1 | .. SPDX-License-Identifier: BSD-3-Clause |
| 2 | Copyright(c) 2017 Wind River Systems, Inc. | |
| 11fdf7f2 TL |
3 | All rights reserved. |
| 4 | ||
| 11fdf7f2 TL |
5 | AVP Poll Mode Driver |
| 6 | ================================================================= | |
| 7 | ||
| 8 | The Accelerated Virtual Port (AVP) device is a shared memory based device | |
| 9 | only available on `virtualization platforms <http://www.windriver.com/products/titanium-cloud/>`_ | |
| 10 | from Wind River Systems. The Wind River Systems virtualization platform | |
| 11 | currently uses QEMU/KVM as its hypervisor and as such provides support for all | |
| 12 | of the QEMU supported virtual and/or emulated devices (e.g., virtio, e1000, | |
| 13 | etc.). The platform offers the virtio device type as the default device when | |
| 14 | launching a virtual machine or creating a virtual machine port. The AVP device | |
| 15 | is a specialized device available to customers that require increased | |
| 16 | throughput and decreased latency to meet the demands of their performance | |
| 17 | focused applications. | |
| 18 | ||
| 19 | The AVP driver binds to any AVP PCI devices that have been exported by the Wind | |
| 20 | River Systems QEMU/KVM hypervisor. As a user of the DPDK driver API it | |
| 21 | supports a subset of the full Ethernet device API to enable the application to | |
| 22 | use the standard device configuration functions and packet receive/transmit | |
| 23 | functions. | |
| 24 | ||
| 25 | These devices enable optimized packet throughput by bypassing QEMU and | |
| 26 | delivering packets directly to the virtual switch via a shared memory | |
| 27 | mechanism. This provides DPDK applications running in virtual machines with | |
| 28 | significantly improved throughput and latency over other device types. | |
| 29 | ||
| 30 | The AVP device implementation is integrated with the QEMU/KVM live-migration | |
| 31 | mechanism to allow applications to seamlessly migrate from one hypervisor node | |
| 32 | to another with minimal packet loss. | |
| 33 | ||
| 34 | ||
| 35 | Features and Limitations of the AVP PMD | |
| 36 | --------------------------------------- | |
| 37 | ||
| 38 | The AVP PMD driver provides the following functionality. | |
| 39 | ||
| 40 | * Receive and transmit of both simple and chained mbuf packets, | |
| 41 | ||
| 42 | * Chained mbufs may include up to 5 chained segments, | |
| 43 | ||
| 44 | * Up to 8 receive and transmit queues per device, | |
| 45 | ||
| 46 | * Only a single MAC address is supported, | |
| 47 | ||
| 48 | * The MAC address cannot be modified, | |
| 49 | ||
| 50 | * The maximum receive packet length is 9238 bytes, | |
| 51 | ||
| 52 | * VLAN header stripping and inserting, | |
| 53 | ||
| 54 | * Promiscuous mode | |
| 55 | ||
| 56 | * VM live-migration | |
| 57 | ||
| 58 | * PCI hotplug insertion and removal | |
| 59 | ||
| 60 | ||
| 61 | Prerequisites | |
| 62 | ------------- | |
| 63 | ||
| 64 | The following prerequisites apply: | |
| 65 | ||
| 66 | * A virtual machine running in a Wind River Systems virtualization | |
| 67 | environment and configured with at least one neutron port defined with a | |
| 68 | vif-model set to "avp". | |
| 69 | ||
| 70 | ||
| 71 | Launching a VM with an AVP type network attachment | |
| 72 | -------------------------------------------------- | |
| 73 | ||
| 74 | The following example will launch a VM with three network attachments. The | |
| 75 | first attachment will have a default vif-model of "virtio". The next two | |
| 76 | network attachments will have a vif-model of "avp" and may be used with a DPDK | |
| 77 | application which is built to include the AVP PMD driver. | |
| 78 | ||
| 79 | .. code-block:: console | |
| 80 | ||
| 81 | nova boot --flavor small --image my-image \ | |
| 82 | --nic net-id=${NETWORK1_UUID} \ | |
| 83 | --nic net-id=${NETWORK2_UUID},vif-model=avp \ | |
| 84 | --nic net-id=${NETWORK3_UUID},vif-model=avp \ | |
| 85 | --security-group default my-instance1 |