> On 30 Nov 2022, at 16:54, Andrew Cooper <andrew.coop...@citrix.com> wrote: > > Generally speaking, the event channel local/remote port is fixed for the > lifetime of the associated domain object. The exception to this is a > secondary XS_INTRODUCE (defined to re-bind to a new event channel) which pokes > around at the domain object's internal state. > > We need to refactor the evtchn handling to support live update, so start by > moving the relevant manipulation into Domain. > > No practical change. > > Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com> > --- > CC: Christian Lindig <christian.lin...@citrix.com> > CC: David Scott <d...@recoil.org> > CC: Edwin Torok <edvin.to...@citrix.com> > CC: Rob Hoes <rob.h...@citrix.com>
Acked-by: Christian Lindig <christian.lin...@citrix.com> The code makes changes around if-expressions and it is easy to get mislead by indentation which parts are covered by an if and which are not in the presence of sequential code. I would be more confident about this with automatic formatting (but also believe this is correct). — C > Note: This change deliberately doesn't reuse Domain.bind_interdomain, which is > removed by the end of the refactoring. > > v2: > * New. > --- > tools/ocaml/xenstored/domain.ml | 12 ++++++++++++ > tools/ocaml/xenstored/process.ml | 6 ++---- > 2 files changed, 14 insertions(+), 4 deletions(-) > > diff --git a/tools/ocaml/xenstored/domain.ml b/tools/ocaml/xenstored/domain.ml > index ab08dcf37f62..d59a9401e211 100644 > --- a/tools/ocaml/xenstored/domain.ml > +++ b/tools/ocaml/xenstored/domain.ml > @@ -63,6 +63,18 @@ let string_of_port = function > let dump d chan = > fprintf chan "dom,%d,%nd,%d\n" d.id d.mfn d.remote_port > > +let rebind_evtchn d remote_port = > + begin match d.port with > + | None -> () > + | Some p -> Event.unbind d.eventchn p > + end; > + let local = Event.bind_interdomain d.eventchn d.id remote_port in > + debug "domain %d rebind (l %s, r %d) => (l %d, r %d)" > + d.id (string_of_port d.port) d.remote_port > + (Xeneventchn.to_int local) remote_port; > + d.remote_port <- remote_port; > + d.port <- Some (local) > + > let notify dom = > match dom.port with > | None -> warn "domain %d: attempt to notify on unknown port" dom.id > diff --git a/tools/ocaml/xenstored/process.ml > b/tools/ocaml/xenstored/process.ml > index b2973aca2a82..2ea940d7e2d5 100644 > --- a/tools/ocaml/xenstored/process.ml > +++ b/tools/ocaml/xenstored/process.ml > @@ -567,11 +567,9 @@ let do_introduce con t domains cons data = > let dom = > if Domains.exist domains domid then > let edom = Domains.find domains domid in > - if (Domain.get_mfn edom) = mfn && > (Connections.find_domain cons domid) != con then begin > + if (Domain.get_mfn edom) = mfn && > (Connections.find_domain cons domid) != con then > (* Use XS_INTRODUCE for recreating the xenbus > event-channel. *) > - edom.remote_port <- remote_port; > - Domain.bind_interdomain edom; > - end; > + Domain.rebind_evtchn edom remote_port; > edom > else try > let ndom = Domains.create domains domid mfn remote_port > in > -- > 2.11.0 >
