[dpdk-dev] [PATCH v9 1/1] net/af_xdp: introduce AF XDP PMD driver

[Luca Boccassi]

On Wed, 2019-04-03 at 17:59 +0800, Ye Xiaolong wrote:
> Hi, Luca
> 
> On 04/02, Luca Boccassi wrote:
> > On Tue, 2019-04-02 at 23:46 +0800, Xiaolong Ye wrote:
> > > diff --git a/drivers/net/af_xdp/Makefile
> > > b/drivers/net/af_xdp/Makefile
> > > new file mode 100644
> > > index 000000000..8343e3016
> > > --- /dev/null
> > > +++ b/drivers/net/af_xdp/Makefile
> > > @@ -0,0 +1,32 @@
> > > +# SPDX-License-Identifier: BSD-3-Clause
> > > +# Copyright(c) 2019 Intel Corporation
> > > +
> > > +include $(RTE_SDK)/mk/rte.vars.mk
> > > +
> > > +#
> > > +# library name
> > > +#
> > > +LIB = librte_pmd_af_xdp.a
> > > +
> > > +EXPORT_MAP := rte_pmd_af_xdp_version.map
> > > +
> > > +LIBABIVER := 1
> > > +
> > > +CFLAGS += -O3
> > > +
> > > +# require kernel version >= v5.1-rc1
> > > +CFLAGS += -I$(RTE_KERNELDIR)/tools/include
> > > +CFLAGS += -I$(RTE_KERNELDIR)/tools/lib/bpf
> > 
> > Sorry for not noticing this before, but doesn't this require the
> > full
> > kernel tree rather than just the typical headers package? Requiring
> > the
> > full kernel tree to be available at build time will make this
> > unbuildable on distros that still use makefiles, like RHEL and
> > SUSE. At
> > least on Debian and Ubuntu, the kernel headers packages distributed
> > do
> > not include the full kernel tree, only the headers, so there's no
> > tools/lib or tools/include.
> 
> Currently we do have dependencies on the kernel src tree, as xsk.h
> and
> asm/barrier wouldn't be installed by libbpf, so before libbpf handles
> these
> properly, can we keep the current RTE_KERNELDIR in Makefile for now,
> and mention
> the dependencies in document, also suggest users to config
> RTE_KERNELDIR to correct
> kernel src tree if they want to use af_xdp pmd?
> 
> Something like:
> 
> dependencies:
> - kernel source code (>= v5.1-rc1)
> - build libbfp and install
> 
> Thanks,
> Xiaolong

asm/barrier.h is installed by the kernel headers packages so it would
be fine (although not ideal) and not need the full source tree.
xsk.h is a bit more worrying, as it looks like an internal header from
here.

Is it really necessary for external applications to use an internal-
only header and a kernel header to be able to use libbpf?

-- 
Kind regards,
Luca Boccassi