X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=doc%2Fguides%2Fsample_app_ug%2Fvhost.rst;h=9112e789706c57591aabcac5e374ff052d1ce303;hb=2808423a9ce42a748aed77a4b487be27d2b6acfa;hp=5735adbb13b1c82290fbe7b815dc4989c9e46941;hpb=7cacb05655397c0c50bcba89eb836d417bc78b69;p=dpdk.git

diff --git a/doc/guides/sample_app_ug/vhost.rst b/doc/guides/sample_app_ug/vhost.rst
index 5735adbb13..9112e78970 100644
--- a/doc/guides/sample_app_ug/vhost.rst
+++ b/doc/guides/sample_app_ug/vhost.rst
@@ -1,34 +1,5 @@
-
-..  BSD LICENSE
-    Copyright(c) 2010-2016 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.
-
+..  SPDX-License-Identifier: BSD-3-Clause
+    Copyright(c) 2010-2016 Intel Corporation.
 
 Vhost Sample Application
 ========================
@@ -176,7 +147,10 @@ retries on an RX burst, it takes effect only when rx retry is enabled. The
 default value is 15.
 
 **--dequeue-zero-copy**
-Dequeue zero copy will be enabled when this option is given.
+Dequeue zero copy will be enabled when this option is given. it is worth to
+note that if NIC is binded to driver with iommu enabled, dequeue zero copy
+cannot work at VM2NIC mode (vm2vm=0) due to currently we don't setup iommu
+dma mapping for guest memory.
 
 **--vlan-strip 0|1**
 VLAN strip option is removed, because different NICs have different behaviors
@@ -204,15 +178,17 @@ Common Issues
   The command above indicates how many hugepages are free to support QEMU's
   allocation request.
 
-* vhost-user will not work with QEMU without the ``-mem-prealloc`` option
+* Failed to build DPDK in VM
 
-  The current implementation works properly only when the guest memory is
-  pre-allocated.
+  Make sure "-cpu host" QEMU option is given.
 
-* vhost-user will not work with a QEMU version without shared memory mapping:
+* Device start fails if NIC's max queues > the default number of 128
 
-  Make sure ``share=on`` QEMU option is given.
+  mbuf pool size is dependent on the MAX_QUEUES configuration, if NIC's
+  max queue number is larger than 128, device start will fail due to
+  insufficient mbuf.
 
-* Failed to build DPDK in VM
+  Change the default number to make it work as below, just set the number
+  according to the NIC's property. ::
 
-  Make sure "-cpu host" QEMU option is given.
+      make EXTRA_CFLAGS="-DMAX_QUEUES=320"