Re: [Xen-devel] [PATCH] libxl: create backend/ xenstore dir for driver domains

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Tue, Mar 24, 2020 at 03:45:30AM +0100, Marek Marczykowski-Górecki wrote:
> On Mon, Mar 23, 2020 at 04:35:12PM +0100, Roger Pau Monné wrote:
> > On Mon, Jan 06, 2020 at 05:03:40PM +0100, Marek Marczykowski-Górecki wrote:
> > > >  * There needs to be a way to deal with a broken/unresponsive driver
> > > >    domain.  That will involve not waiting for the backend so must
> > > >    involve simply deleting the backend from xenstore.
> > > 
> > > It's already there: if driver domain fails to set .../state = 6 within
> > > a timeout, toolstack will forcibly remove the entry.
> > 
> > Would it work to change this and instead of monitor .../state = 6
> > monitor that the parent directory still exist?
> 
> That could be a good idea, to avoid introducing yet another (set of)
> callback. I'll look into it, it may require different handling of
> dom0/non-dom0 backend.

Yes, the domain handling the backend needs to watch .../state, while
the control domain (where the toolstack actually runs) would need to
watch .../ AFAICT.

As you say, I think you could maybe reuse some of the code and add a
special case for the toolstack domain when the backend runs in a
driver domain.

Thanks, Roger.