| John DeNisco | 06dcd45 | 2018-07-26 12:45:10 -0400 | [diff] [blame] | 1 | .. _vhost05: |
| 2 | |
| 3 | Limitations |
| 4 | ----------- |
| 5 | There are some limitations when using the qemu vhost driver. Some are described in this section. |
| 6 | |
| 7 | Performance |
| 8 | ^^^^^^^^^^^ |
| 9 | |
| 10 | VPP performance with vHost is limited by the Qemu vHost driver. FD.io VPP 18.04 CSIT vHost testing |
| 11 | shows with 2 threads, 2 cores and a Queue size of 1024 the maximum NDR throughput was about 7.5 Mpps. |
| 12 | This is about the limit at this time. |
| 13 | |
| 14 | For all the details on the CSIT VM vhost connection refer to the |
| 15 | `CSIT VM vHost performance tests <https://docs.fd.io/csit/rls1804/report/vpp_performance_tests/packet_throughput_graphs/vm_vhost.html>`_. |
| 16 | |
| 17 | |
| 18 | Features |
| 19 | ^^^^^^^^ |
| 20 | |
| 21 | These are the features not supported with FD.io VPP vHost. |
| 22 | |
| 23 | * VPP implements vHost in device mode only. VPP is intended to work with Qemu which implements vHost in driver mode, it does not implement vHost driver mode. |
| 24 | * VPP vHost implementation does not support checksum or transmit segmentation offload. |
| 25 | * VPP vHost implementation does not support packet receive filtering feature for controlling receive traffic. |