On 09/11/2020 7:09, Leon Romanovsky wrote: > On Sun, Nov 08, 2020 at 07:49:35PM -0400, Jason Gunthorpe wrote: >> On Sun, Nov 08, 2020 at 03:03:45PM +0200, Gal Pressman wrote: >>> On 05/11/2020 22:00, Jason Gunthorpe wrote: >>>> On Tue, Nov 03, 2020 at 05:45:26PM +0200, Gal Pressman wrote: >>>>> On 03/11/2020 16:22, Jason Gunthorpe wrote: >>>>>> On Tue, Nov 03, 2020 at 04:11:19PM +0200, Gal Pressman wrote: >>>>>>> On 03/11/2020 15:57, Leon Romanovsky wrote: >>>>>>>> On Tue, Nov 03, 2020 at 09:45:22AM -0400, Jason Gunthorpe wrote: >>>>>>>>> On Tue, Nov 03, 2020 at 03:26:27PM +0200, Gal Pressman wrote: >>>>>>>>>> Add the ability to query the device's bdf through rdma tool netlink >>>>>>>>>> command (in addition to the sysfs infra). >>>>>>>>>> >>>>>>>>>> In case of virtual devices (rxe/siw), the netdev bdf will be shown. >>>>>>>>> >>>>>>>>> Why? What is the use case? >>>>>>>> >>>>>>>> Right, and why isn't netdev (RDMA_NLDEV_ATTR_NDEV_NAME) enough? >>>>>>> >>>>>>> When taking system topology into consideration you need some way to pair the >>>>>>> ibdev and bdf, especially when working with multiple devices. >>>>>>> The netdev name doesn't exist on devices with no netdevs (IB, EFA). >>>>>> >>>>>> You are supposed to use sysfs >>>>>> >>>>>> /sys/class/infiniband/ibp0s9/device >>>>>> >>>>>> Should always be the physical device >>>>>> >>>>>>> Why rdma tool? Because it's more intuitive than sysfs. >>>>>> >>>>>> But we generally don't put this information into netlink BDF is just >>>>>> the start, you need all the other topology information to make sense >>>>>> of it, and all that is in sysfs only already >>>>> >>>>> As the commit message says, it's in addition to the device sysfs. >>>>> >>>>> Many (if not most) of the existing rdma netlink commands are duplicates of some >>>>> sysfs entries, but show it in a more "modern" way. >>>>> I'm not convinced that bdf should be treated differently. >>>> >>>> Why did you call it BDF anyhow? it has nothing to do with PCI BDF >>>> other than it happens to be the PDF for PCI devices. Netdev called >>>> this bus_info >>> >>> Are there non pci devices in the subsystem? >> >> Yes, HNS uses non-pci devices >> >>> I can rename to a more fitting name, will change to bus_info unless >>> someone has a better idea. >> >> The thing is, is is still useless. You have to consult sysfs to >> understand what bus it is scoped on to do anything further with >> it. Can't just assume it is PCI. > > Can anyone please remind me why are we doing it? > What problem do you solve here by adding new nldev attributes? https://lore.kernel.org/linux-rdma/0825e1bf-f913-d2c1-ad3f-35ba3d6b75ef@xxxxxxxxxx/
