On Thu, 2021-07-15 at 13:59 +0000, David Ramirez wrote: > Hey all, > > I am having issues with calling some bpf helper functions > when running my XDP program in driver on the mlx5_core driver. > Several of the helpers I've tried to use for ringbuf and maps always > return 0. > While this may seem to imply that for functions that merely return > null instead of > a pointer in case of an error are working as intended, > some functions which return negative on failure and 0 on success are > are also affected, > as while they return 0, they do not result in the desired effect. > > Observed examples: > - bpf_ringbuf_output always returns 0, but no data is pushed to the > ringbuf > - bpf_map_update_elem always returns 0, but the element is not > updated > - bpf_ringbuf_reserve always returns 0 > - bpf_map_lookup_elem always returns 0 > > I'm uncertain if this is a driver specific issue or an ebpf issue. this is purely ebpf issue or user prog issue. 1. the ebpf program/helpers are agnostic to run mode, driver/native v.s. skb/generic modes. 2. the above helpers are pure bpf callbacks, the driver is not involved. > Testing with xdp in driver mode on veth devices works as expected, > which suggests this is more likely a driver issue. > The driver or its implementation are not involved with the above helpers, so further debug is required in the user prog or the helpers logic themselves. > Additional Details: > > Linux Distro: Ubuntu 21.04 > Linux Kernel version: 5.11.0-18-generic > driver: mlx5_core > version: 5.11.0-18-generic > > Thank you, > David Ramirez
