> -----Original Message----- > From: Denis Kirjanov <k...@linux-powerpc.org> > Sent: 06 May 2020 18:45 > To: p...@xen.org > Cc: netdev@vger.kernel.org; jgr...@suse.com; wei....@kernel.org; > ilias.apalodi...@linaro.org > Subject: Re: [PATCH net-next v7 2/2] xen networking: add XDP offset > adjustment to xen-netback > > On 5/5/20, Paul Durrant <xadimg...@gmail.com> wrote: > >> -----Original Message----- > >> >> @@ -417,6 +431,11 @@ static void frontend_changed(struct xenbus_device > >> >> *dev, > >> >> set_backend_state(be, XenbusStateConnected); > >> >> break; > >> >> > >> >> + case XenbusStateReconfiguring: > >> >> + read_xenbus_frontend_xdp(be, dev); > >> > > >> > Is the frontend always expected to trigger a re-configure, or could > >> > feature-xdp already be enabled prior to connection? > >> > >> Yes, feature-xdp is set by the frontend when xdp code is loaded. > >> > > > > That's still ambiguous... what I'm getting at is whether you also need to > > read the xdp state when transitioning into Connected as well as > > Reconfiguring? > > I have to read the state only during the Reconfiguring state since > that's where an XDP program is loaded / unloaded and then we transition > from Reconfigred to Connected >
Ok, but what about netback re-connection? It is possible that netback can be disconnected, unloaded, reloaded and re-attached to a running frontend. In this case XDP would be active so I still think read_xenbus_frontend_xdp() needs to form part of ring connection (if only in this case). Paul
