On Fri, Jul 12, 2019 at 07:57:19PM +0530, Potnuri Bharat Teja wrote: > Hi all, > I observe the following behavior on one of my machines configured for siw. > > Issue: > SIW device gets wrong device ops (HW/real rdma driver device ops) instead of > siw device ops due to improper device matching. > > Root-cause: > In libibverbs, during user cma initialisation, for each entry from the driver > list, sysfs device is checked for matching name or device. > If the siw/rxe driver is at the head of the list, then sysfs device matches > properly with the corresponding siw driver and gets the corresponding siw/rxe > device ops. Now, If the siw/rxe driver is after the real HW driver cxgb4/mlx5 > respectively in the driver list, then siw sysfs device matches pci device and > wrongly gets the device ops of HW driver (cxgb4/mlx5). > > Below debug prints from verbs_register_driver() and driver_list entries, where > siw is after cxgb4. I see verbs alloc context landing in cxgb4_alloc_context > instead of siw_alloc_context, thus breaking user siw. > > <debug> verbs_register_driver_22: 184: driver 0x176e370 > <debug> verbs_register_driver_22: 185: name ipathverbs > <debug> verbs_register_driver_22: 184: driver 0x176f6a0 > <debug> verbs_register_driver_22: 185: name cxgb4 > <debug> verbs_register_driver_22: 184: driver 0x176fd50 > <debug> verbs_register_driver_22: 185: name cxgb3 > <debug> verbs_register_driver_22: 184: driver 0x1777020 > <debug> verbs_register_driver_22: 185: name rxe > <debug> verbs_register_driver_22: 184: driver 0x1770a30 > <debug> verbs_register_driver_22: 185: name siw > <debug> verbs_register_driver_22: 184: driver 0x1771120 > <debug> verbs_register_driver_22: 185: name mlx4 > <debug> verbs_register_driver_22: 184: driver 0x1771990 > <debug> verbs_register_driver_22: 185: name mlx5 > <debug> verbs_register_driver_22: 184: driver 0x1771ff0 > <debug> verbs_register_driver_22: 185: name efa > > <debug> try_drivers: 372: driver 0x176e370, sysfs_dev 0x1776b20, name: ipathverbs > <debug> try_drivers: 372: driver 0x176f6a0, sysfs_dev 0x1776b20, name: cxgb4 > <debug> try_drivers: 372: driver 0x176fd50, sysfs_dev 0x1776b20, name: cxgb3 > <debug> try_drivers: 372: driver 0x1777020, sysfs_dev 0x1776b20, name: rxe > <debug> try_drivers: 372: driver 0x1770a30, sysfs_dev 0x1776b20, name: siw > <debug> try_drivers: 372: driver 0x1771120, sysfs_dev 0x1776b20, name: mlx4 > <debug> try_drivers: 372: driver 0x1771990, sysfs_dev 0x1776b20, name: mlx5 > <debug> try_drivers: 372: driver 0x1771ff0, sysfs_dev 0x1776b20, name: efa > > Proposed fix: > I have the below fix that works. It adds siw/rxe driver to the HEAD of the > driver list and the rest to the tail. I am not sure if this fix is the ideal > one, so I am attaching it to this mail. Update your rdma-core to latest and this will be fixed fully by using netlink to match the siw device.. Jason
