[PATCH v2 2/3] doc: update vhost sample app docs

[Herakliusz Lipiec <herakliusz.lipiec@intel.com>]

Vhost sample app documentation describes parameters that are not in the
code and omits parameters that exist. Also switching the order of
sections on running vhost and VM, since the --client parameter in the
sample line requires a socket to be created by VM. Removing uio
references and updating with vfio-pci.

Signed-off-by: Herakliusz Lipiec <herakliusz.lipiec@intel.com>
---
V2:
 * Rewording portmask description as suggested by Chenbo.
---
 doc/guides/sample_app_ug/vhost.rst | 67 ++++++++++++++++--------------
 1 file changed, 35 insertions(+), 32 deletions(-)

diff --git a/doc/guides/sample_app_ug/vhost.rst b/doc/guides/sample_app_ug/vhost.rst
index 3c3cfdcd2d..8e7646b805 100644
--- a/doc/guides/sample_app_ug/vhost.rst
+++ b/doc/guides/sample_app_ug/vhost.rst
@@ -33,19 +33,7 @@ The application is located in the ``vhost`` sub-directory.
 .. note::
    In this example, you need build DPDK both on the host and inside guest.
 
-Start the vswitch example
-~~~~~~~~~~~~~~~~~~~~~~~~~
-
-.. code-block:: console
-
-        ./dpdk-vhost -l 0-3 -n 4 --socket-mem 1024  \
-             -- --socket-file /tmp/sock0 --client \
-             ...
-
-Check the `Parameters`_ section for the explanations on what do those
-parameters mean.
-
-.. _vhost_app_run_vm:
+. _vhost_app_run_vm:
 
 Start the VM
 ~~~~~~~~~~~~
@@ -66,6 +54,19 @@ Start the VM
     some specific features, a higher version might be need. Such as
     QEMU 2.7 (or above) for the reconnect feature.
 
+
+Start the vswitch example
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. code-block:: console
+
+        ./dpdk-vhost -l 0-3 -n 4 --socket-mem 1024  \
+             -- --socket-file /tmp/sock0 --client \
+             ...
+
+Check the `Parameters`_ section for the explanations on what do those
+parameters mean.
+
 .. _vhost_app_run_dpdk_inside_guest:
 
 Run testpmd inside guest
@@ -77,8 +78,8 @@ could be done by:
 
 .. code-block:: console
 
-   modprobe uio_pci_generic
-   dpdk/usertools/dpdk-devbind.py -b uio_pci_generic 0000:00:04.0
+   modprobe vfio-pci
+   dpdk/usertools/dpdk-devbind.py -b vfio-pci 0000:00:04.0
 
 Then start testpmd for packet forwarding testing.
 
@@ -87,6 +88,9 @@ Then start testpmd for packet forwarding testing.
     ./<build_dir>/app/dpdk-testpmd -l 0-1 -- -i
     > start tx_first
 
+For more information about vIOMMU and NO-IOMMU and VFIO please refer to
+:doc:`/../linux_gsg/linux_drivers` section of the DPDK Getting started guide.
+
 Inject packets
 --------------
 
@@ -146,26 +150,10 @@ The rx-retry-delay option specifies the timeout (in micro seconds) between
 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. it is worth to
-note that if NIC is bound 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
-when disabling VLAN strip. Such feature, which heavily depends on hardware,
-should be removed from this example to reduce confusion. Now, VLAN strip is
-enabled and cannot be disabled.
-
 **--builtin-net-driver**
 A very simple vhost-user net driver which demonstrates how to use the generic
 vhost APIs will be used when this option is given. It is disabled by default.
 
-**--dma-type**
-This parameter is used to specify DMA type for async vhost-user net driver which
-demonstrates how to use the async vhost APIs. It's used in combination with dmas.
-
 **--dmas**
 This parameter is used to specify the assigned DMA device of a vhost device.
 Async vhost-user net driver will be used if --dmas is set. For example
@@ -173,6 +161,20 @@ Async vhost-user net driver will be used if --dmas is set. For example
 device 0 enqueue operation and use DMA channel 00:04.1 for vhost device 1
 enqueue operation.
 
+**--total-num-mbufs 0-N**
+This parameter sets the number of mbufs to be allocated in mbuf pools,
+the default value is 147456. This is can be used if launch of a port fails
+due to shortage of mbufs.
+
+**--tso 0|1**
+Disables/enables TCP segment offload.
+
+**--tx-csum 0|1**
+Disables/enables TX checksum offload.
+
+**-p mask**
+Port mask which specifies the ports to be used
+
 Common Issues
 -------------
 
@@ -201,7 +203,8 @@ Common Issues
 
   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.
+  insufficient mbuf. This can be adjusted using ``--total-num-mbufs``
+  parameter.
 
 * Option "builtin-net-driver" is incompatible with QEMU
 
-- 
2.36.1