[libvirt] [discuss] add reconnect support for vhost-user

[Michal Privoznik]

On 08/22/2017 03:54 AM, lu.zhipeng at zte.com.cn wrote:
> Hello everyone:
> 
>  I want to implement a function, it is unclear whether anyone has submitted such a patch. 
> 
> add reconnect support for vhost-user when unix control socket between vhost-user and vhost-user backend is   disconnected .
> 
> 
> 
> 
> xml 
> 
> 
> 
>  <interface type='vhostuser'>
> 
>       <mac address='fa:16:3e:10:23:01'/>
> 
>       <source type='unix' path='/opt/network/ovdk/bin/vhost.sock' reconnect='10' mode='client'/> ----------reconnect 
> 
>       <model type='virtio'/>

I don't think I've seen any patch for this ever. However, it's
questionable whether we should have this setting in the form you
suggest. I mean, for timeout for OVS we have ovs_timeout setting in the
libvirtd.conf config file. Maybe we can have ovs_reconnect in there too?

Also, how does this work? Is it something that libvirt has to actively
check for and if a disconnect is detected libvirt has to take an action?
Or is this something that we tell qemu and whenever it loses connection
it tries to reconnect after 10 seconds? So how is the interface device
affected while it's disconnected from the socket?

Michal