On Fri, 2019-02-08 at 15:17 -0800, Saeed Mahameed wrote: > On Thu, 2019-02-07 at 19:08 +0000, Saeed Mahameed wrote: > > > > So > > 1) on dev_map_update_elem() we will call > > dev->dev->ndo_bpf() to notify the device on the intention to > > start/stop > > redirect, and wait for it to create/destroy the HW resources > > before/after actually updating the map > > > > silly me, dev_map_update_elem must be atomic, we can't hook driver > resource allocation to it, it must come as a separate request > (syscall) > from user space to request to create XDP redirect resources. >
Well, it is possible to render dev_map_update_elem non-atomic and fail BPF programs who try to update it in the verifier check_map_func_compatibility. if you know of any case where devmap needs to be updated from the BPF program please let me know.
