Initial commit of Sphinx docs

Change-Id: I9fca8fb98502dffc2555f9de7f507b6f006e0e77
Signed-off-by: John DeNisco <jdenisco@cisco.com>

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diff --git a/docs/usecases/vhost/vhost05.rst b/docs/usecases/vhost/vhost05.rst
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+.. _vhost05:
+
+Limitations
+-----------
+There are some limitations when using the qemu vhost driver. Some are described in this section.
+
+Performance
+^^^^^^^^^^^
+
+VPP performance with vHost is limited by the Qemu vHost driver. FD.io VPP 18.04 CSIT vHost testing
+shows with 2 threads, 2 cores and a Queue size of 1024 the maximum NDR throughput was about 7.5 Mpps.
+This is about the limit at this time.
+
+For all the details on the CSIT VM vhost connection refer to the 
+`CSIT VM vHost performance tests <https://docs.fd.io/csit/rls1804/report/vpp_performance_tests/packet_throughput_graphs/vm_vhost.html>`_.
+
+
+Features
+^^^^^^^^
+
+These are the features not supported with FD.io VPP vHost.
+
+* 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.
+* VPP vHost implementation does not support checksum or transmit segmentation offload.
+* VPP vHost implementation does not support packet receive filtering feature for controlling receive traffic.