Re: [PATCH v13 17/17] net: stream: add QAPI events to report connection state

[Stefano Brivio <sbrivio@xxxxxxxxxx>]

[Cc: Laine, full quote]

On Fri, 21 Oct 2022 11:12:20 +0200
Markus Armbruster <armbru@xxxxxxxxxx> wrote:

> Cc: Stefano Brivio
> 
> Laurent Vivier <lvivier@xxxxxxxxxx> writes:
> 
> > On 10/21/22 07:48, Markus Armbruster wrote:  
> >> Laurent Vivier <lvivier@xxxxxxxxxx> writes:
> >>   
> >>> The netdev reports NETDEV_STREAM_CONNECTED event when the backend
> >>> is connected, and NETDEV_STREAM_DISCONNECTED when it is disconnected.  
> >>
> >> Use cases?  
> >
> > This is asked by Stefano Brivio to allow libvirt to detect if connection to 
> > passt is lost and to restart passt.  
> 
> Let's add something like this to the commit message:
> 
>     This lets libvirt notice when the connection is lost somehow, and
>     restart the peer (such as passt).
> 
> Who's working on the libvirt part?

Laine Stump and myself. Nothing to show yet, though.

> > I have also a patch to add a "reconnect=seconds" option, but I didn't want 
> > to add it to this series.  
> 
> It's okay to mention future work in commit messages, but not required.
> 
> >> Could similar event signalling be useful for other kinds of netdev
> >> backends?  
> >
> > I was wondering, but it becomes more complicated to be generic.  
> 
> Making something complicated and generic where a simpler special
> solution would do is the worst.
> 
> Not quite as bad (but still plenty bad) is making a few special
> solutions first, then replace them all with a generic solution.
> 
> I believe we should have a good, hard think on possible applications of
> a generic solution now.
> 
> There is no need to hold back this series for that.
> 
> If we conclude a generic solution is called for, we better replace this
> special solution before it becomes ABI.  Either by replacing it before
> we release it, or by keeping it unstable until we replace it.

-- 
Stefano