> -----Original Message----- > From: Greg KH [mailto:gregkh@xxxxxxxxxxxxxxxxxxx] > Sent: Saturday, December 10, 2016 7:21 AM > To: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx> > Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>; olaf@xxxxxxxxx; > jasowang@xxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > bjorn.helgaas@xxxxxxxxx; apw@xxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx; > leann.ogasawara@xxxxxxxxxxxxx > Subject: Re: [PATCH 3/3] hv_netvsc: Implement VF matching based on > serial numbers > > On Fri, Dec 09, 2016 at 04:21:48PM -0800, Stephen Hemminger wrote: > > On Fri, 9 Dec 2016 22:35:05 +0000 > > Haiyang Zhang <haiyangz@xxxxxxxxxxxxx> wrote: > > > > > > > > > > > > > > Emulated NIC is already excluded in start of netvc notifier > handler. > > > > > > > > > > > > static int netvsc_netdev_event(struct notifier_block *this, > > > > > > unsigned long event, void *ptr) > > > > > > { > > > > > > struct net_device *event_dev = > netdev_notifier_info_to_dev(ptr); > > > > > > > > > > > > /* Skip our own events */ > > > > > > if (event_dev->netdev_ops == &device_ops) > > > > > > return NOTIFY_DONE; > > > > > > > > > > > > > > > > Emulated device is not based on netvsc. It's the native Linux > > > > (dec100M?) > > > > > Driver. So this line doesn't exclude it. And how about other NIC > type > > > > > may be added in the future? > > > > > > > > Sorry, forgot about that haven't used emulated device in years. > > > > The emulated device should appear to be on a PCI bus, but the > serial > > > > would not match?? > > > > > > It's not a vmbus device, not a hv_pci device either. Hv_PCI is a > subset > > > of vmbus devices. So emulated NIC won't have hv_pci serial number. > > > > > > In my patch, the following code ensure, we only try to get serial > number > > > after confirming it's vmbus and hv_pci device: > > > > > > + if (!dev_is_vmbus(dev)) > > > + continue; > > > + > > > + hdev = device_to_hv_device(dev); > > > + if (hdev->device_id != HV_PCIE) > > > + continue; > > > > Ok, the walk back up the device tree is logically ok, but I don't > > know enough about PCI device tree to be assured that it is safe. > > Also, you could short circuit away most of the unwanted devices > > by making sure the vf_netdev->dev.parent is a PCI device. > > Ugh, this seems really really messy. Can't we just have the > netdev_event interface pass back a pointer to something that we "know" > what it is? This walking the device tree is a mess, and not good. > > I'd even argue that dev_is_pci() needs to be removed from the tree too, > as it shouldn't be needed either. We did a lot of work on the driver > model to prevent the need for having to declare the "type" of 'struct > device' at all, and by doing this type of thing it goes against the > basic design of the model. > > Yes, it makes things a bit "tougher" in places, but you don't do crazy > things like walk device trees to try to find random devices and then > think it's safe to actually use them :( > We register a notifier_block with: register_netdevice_notifier(struct notifier_block *nb) The "struct notifier_block" basically contains a callback function: struct notifier_block { notifier_fn_t notifier_call; struct notifier_block __rcu *next; int priority; }; It doesn't specify which device we want, so all net devices can trigger this event. Seems we can't have this notifier return VF device only. Thanks, - Haiyang _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
