> -----Original Message----- > From: Dexuan Cui <decui@xxxxxxxxxxxxx> > Sent: Tuesday, January 30, 2024 3:13 PM > To: Shradha Gupta <shradhagupta@xxxxxxxxxxxxxxxxxxx>; KY Srinivasan > > > @@ -2205,8 +2209,11 @@ static int netvsc_vf_join(struct net_device > > *vf_netdev, > > ndev->name, ret); > > goto upper_link_failed; > > } > > - > > - schedule_delayed_work(&ndev_ctx->vf_takeover, > > VF_TAKEOVER_INT); > > + /* If this registration is called from probe context vf_takeover > > + * is taken care of later in probe itself. > I suspect "later in probe itself" is not accurate. > If 'context' is VF_REG_IN_PROBE, I suppose what happens here is: > after netvsc_probe() finishes, the netvsc interface becomes available, > so the user space will ifup it, and netvsc_open() will UP the VF > interface, > and netvsc_netdev_event() is called for the VF with event == > NETDEV_POST_INIT (?) and NETDEV_CHANGE, and the data path is > switched to the VF. In register_netdevice(), NETDEV_POST_INIT is earlier than NETDEV_REGISTER. This case: netvsc_open >> dev_open(vf) >> NETDEV_UP >> netvsc_vf_changed(event_dev, event); > > If my understanding is correct, I think in the case of 'context' == > VF_REG_IN_PROBE, I suspect the "Align MTU of VF with master" > and the "sync address list from ndev to VF" in __netvsc_vf_setup() are > omitted? If so, should this be fixed? e.g. Not sure if the below is an > issue or not: > 1) a VF is bound to a NetVSC interface, and a user sets the MTUs to 1024. > 2) rmmod hv_netvsc > 3) modprobe hv_netvsc > 4) the netvsc interface uses MTU=1500 (the default), and the VF still > uses 1024. __netvsc_vf_setup() is skipped from the netvsc_register_vf >> netvsc_vf_join(), but called from netvsc_probe(), so the VF mtu is sync-ed to 1500. I verified mtu sync in test. Thanks, - Haiyang
