On 08/09/2017 11:26 PM, David Miller wrote:
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.
Ok, sure, I'll do a v2 with that included. Thanks!