Re: [Qemu-devel] Question about VM inner route entry's lost when vhost-user reconnect

[Lilijun (Jerry, Cloud Networking)]

Hi, Stefan

This problem is related with backend vhost-user socket abnormal cases, we 
shouldn't ask customers to configure it manually for backend's issues or 
depends on guest OS's network configuration.

Thanks

> -----Original Message-----
> From: Stefan Hajnoczi [mailto:address@hidden
> Sent: Wednesday, March 06, 2019 6:07 PM
> To: Lilijun (Jerry, Cloud Networking) <address@hidden>
> Cc: address@hidden; wangxin (U)
> <address@hidden>; wangyunjian
> <address@hidden>
> Subject: Re: [Qemu-devel] Question about VM inner route entry's lost when
> vhost-user reconnect
> 
> On Mon, Mar 04, 2019 at 08:26:23AM +0000, Lilijun (Jerry, Cloud Networking)
> wrote:
> >       I am running my VM using vhost-user NIC with OVS-DPDK.  The steps of
> my question is shown as follows:
> >      1) In the VM, I add one route entry manually on the vNIC eth0 using the
> linux tool route.
> >      2) When restarting openvswitch service for the crash of the 
> > ovs-vswitchd,
> qemu's vhost-user reconnected successfully after 40s.
> >      3) Here VM's vNIC will receive link down and up events, the interval
> between the two events is about 40s.
> >      3) But that route entry disappeared and that will cause user's network
> traffic interruption and the service failed.
> >
> >      Is there some work on this problem?  Can we keep the vNIC's link up
> status when do vhost-user's reconnecting work?
> 
> Can you add the custom route to the network management tool inside the
> guest so that it will be reinstated when the link comes back up?
> 
> The details of how to do this depend on the guest's distro.
> 
> Stefan