From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ye Xiaolong <xiaolong.ye@intel.com>
Subject: Re: [PATCH v8 2/2] examples/vdpa: introduce a new sample
 for	vDPA
Date: Thu, 17 Jan 2019 23:13:27 +0800
Message-ID: <20190117151327.GA54315@intel.com>
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 <20180928214747.48938-3-xiaolong.ye@intel.com>
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Cc: "dev@dpdk.org" <dev@dpdk.org>,
 Maxime Coquelin <maxime.coquelin@redhat.com>,
 Tiwei Bie <tiwei.bie@intel.com>, Zhihong Wang <zhihong.wang@intel.com>,
 "xiao.w.wang@intel.com" <xiao.w.wang@intel.com>,
 Rami Rosen <roszenrami@gmail.com>, Wang Haiyue <haiyue.wang@intel.com>
To: Shahaf Shuler <shahafs@mellanox.com>
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Hi,

On 01/17, Shahaf Shuler wrote:
>Hi, 
>
>Going back to this merged commit, 
>
>Saturday, September 29, 2018 12:48 AM, Xiaolong Ye:
>> Subject: [dpdk-dev] [PATCH v8 2/2] examples/vdpa: introduce a new sample
>> for vDPA
>> 
>> The vdpa sample application creates vhost-user sockets by using the vDPA
>> backend. vDPA stands for vhost Data Path Acceleration which utilizes virtio
>> ring compatible devices to serve virtio driver directly to enable datapath
>> acceleration. As vDPA driver can help to set up vhost datapath, this
>> application doesn't need to launch dedicated worker threads for vhost
>> enqueue/dequeue operations.
>> 
>> Signed-off-by: Xiaolong Ye <xiaolong.ye@intel.com>
>> Acked-by: Xiao Wang <xiao.w.wang@intel.com>
>> Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
>> ---
>
>[...]
>
>> +
>> +Start the VMs
>> +~~~~~~~~~~~~~
>> +
>> +.. code-block:: console
>> +
>> +       qemu-system-x86_64 -cpu host -enable-kvm \
>> +       <snip>
>> +       -mem-prealloc \
>> +       -chardev socket,id=char0,path=<socket_file created in above steps> \
>> +       -netdev type=vhost-user,id=vdpa,chardev=char0 \
>> +       -device
>> + virtio-net-pci,netdev=vdpa,mac=00:aa:bb:cc:dd:ee,page-per-vq=on \
>
>
>It doesn't seems like qemu has the id=vdpa and netdev=vdpa options. 
>Grepping vdpa on qemu returns empty. 
>
>Am using QEMU v3.1.0-513-gfb177a0. Commit head is fb177a036f2e ("MAINTAINERS: Mark RISC-V as Supported").
>
>Did I missed anything?
>

Not quite sure about your question here, the vdpa used in above qemu cmdline
is just a normal string, you can replace it with other string like 

-netdev type=vhost-user,id=mynet,chardev=char0 \
-device virtio-net-pci,netdev=mynet,...

The major support for vdpa is done in dpdk side as the vhost user backend, qemu
will use normal vhost user protocol to communicate with it.

Thanks,
Xiaolong