examples/vhost: how to use vhost-switch between VMs? Anybody who can help?

examples/vhost: how to use vhost-switch between VMs? Anybody who can help?

[wang.yong19]

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  There are some descriptions in 
dpdk-16.11\doc\guides\sample_app_ug\vhost.rst,
"The sample application performs simple packet switching between virtual 
machines based on Media Access Control (MAC) address or Virtual Local Area 

Network (VLAN) tag." So, we want to use vhost-switch between two VMs, one 
work as server and another as client.
  We runned the vhost-switch sample in a VM with three virtio ports. 
First, we 
binded one virtio port to igb_uio. Then we runned the command
"./vhost-switch -c f -n 4 --socket-mem 1024 -- --socket-file /tmp/sock0 
¨C-vm2vm 1 ¨C-dequeue-zero-copy"
And then error occured. We found that the 'dev_info.max_vmdq_pools' of the 
virtio
port was 0, and division by zero error occured at the statement 
'queues_per_pool = dev_info.vmdq_queue_num / dev_info.max_vmdq_pools;'
We fixed this by assigning 'queues_per_pool' to 0 if 
'dev_info.max_vmdq_pools'
was 0, but there were still other errors when running vhost-switch. 
  After we fixed all the errors while running vhost-switch as server, we 
didn't
know how to run the vhost-switch as client in another VM, how could the 
client 
get the socket, the netdev and the virtio port that the server 
vhost-switch 
created?
  So, we doubted whether we use the vhost-switch in a wrong way. Could you
please give us some advice that how to use the vhost-switch between two or 
more
 VMs?
  Anybody who can help us with this?

Re: examples/vhost: how to use vhost-switch between VMs? Anybody who can help?

[Yuanhan Liu]

On Tue, Dec 27, 2016 at 01:33:14PM +0800, wang.yong19@zte.com.cn wrote:
>   There are some descriptions in 
> dpdk-16.11\doc\guides\sample_app_ug\vhost.rst,
> "The sample application performs simple packet switching between virtual 
> machines based on Media Access Control (MAC) address or Virtual Local Area 
> 
> Network (VLAN) tag." So, we want to use vhost-switch between two VMs, one 
> work as server and another as client.
>   We runned the vhost-switch sample in a VM with three virtio ports. 
> First, we 
> binded one virtio port to igb_uio. Then we runned the command
> "./vhost-switch -c f -n 4 --socket-mem 1024 -- --socket-file /tmp/sock0 
> ?C-vm2vm 1 ?C-dequeue-zero-copy"
> And then error occured. We found that the 'dev_info.max_vmdq_pools' of the 
> virtio
> port was 0, and division by zero error occured at the statement 
> 'queues_per_pool = dev_info.vmdq_queue_num / dev_info.max_vmdq_pools;'
> We fixed this by assigning 'queues_per_pool' to 0 if 
> 'dev_info.max_vmdq_pools'
> was 0, but there were still other errors when running vhost-switch. 
>   After we fixed all the errors while running vhost-switch as server, we 
> didn't
> know how to run the vhost-switch as client in another VM, how could the 

vhost-switch runs on the host but not guest, and there is no such thing
like "vhost-switch as client". Just think it's (pretty simple) switch,
that could link VMs together.

If you are interested in DPDK virtio PMD, we normally run testpmd inside
the guest. If not, you could just use the virtio-net driver from the
linux kernel, whereas you normally should set the IP address manually.

	--yliu

> client 
> get the socket, the netdev and the virtio port that the server 
> vhost-switch 
> created?
>   So, we doubted whether we use the vhost-switch in a wrong way. Could you
> please give us some advice that how to use the vhost-switch between two or 
> more
>  VMs?
>   Anybody who can help us with this?
>