From: Daniel Borkmann <dan...@iogearbox.net> Date: Wed, 09 Aug 2017 22:32:34 +0200
> For the case of cilium, we are not in control of the kernel, by > the way, we run a few probes that are small BPF insns snippets > that test the kernel for presence of certain features (e.g. helper, > verifier, maps) and enable/disable them accordingly later in the > code generation. On the user space side, we're indeed a bit more > flexible and have no such restriction. > > Plan is for LLVM as one of the frontends that generate byte code > (ply, for example, can probe the kernel directly for its code > generation) to have i) a target specific option to offer a > possibility to explicitly enable the extension by the user (as we > have with -m target specific extensions today for various cpu > insns), and ii) have the kernel check for presence of the extensions > and enable it transparently when the user selects more aggressive > options such as -march=native in a bpf target context, so we can > select the underlying features transparently. I should have made > that more clear earlier, sorry about that. I think this explanation needs to be in either your header posting or the commit message of patch #1. Thanks :)
