On 12/05/2021 15:15, Patrick Wildt wrote: > Hi, > > when hvn(4) attaches it sends commands and waits for replies to come > back in, hence the interrupt function is being polled. Unfortunately > it seems that the 'receive pipe' has both command completion and data > packets. As it turns out, while hvn(4) is just setting up the pipes, > it can already receive packets, which I have seen happening on Hyper-V. > > This essentially means that if_input() is being called *before* the > card is set up (or UP). This seems wrong. Apparently on drivers like > em(4) we only read packets if IFF_RUNNING is set. I think in the case > of hvn(4), we should drop packets unless IFF_RUNNING is set. > > Opinions? >
Hi Patrick, You're right that hvn needs to have the receiving path setup to exchange commands with the hypervisor. This diff LGTM and should be committed if it wasn't. Cheers, Mike > Patrick > > diff --git a/sys/dev/pv/if_hvn.c b/sys/dev/pv/if_hvn.c > index f12e2f935ca..4306f717baf 100644 > --- a/sys/dev/pv/if_hvn.c > +++ b/sys/dev/pv/if_hvn.c > @@ -1470,7 +1470,10 @@ hvn_rndis_input(struct hvn_softc *sc, uint64_t tid, > void *arg) > } > hvn_nvs_ack(sc, tid); > > - if_input(ifp, &ml); > + if (ifp->if_flags & IFF_RUNNING) > + if_input(ifp, &ml); > + else > + ml_purge(&ml); > } > > static inline struct mbuf * >
