From mboxrd@z Thu Jan  1 00:00:00 1970
From: Luca Boccassi <bluca@debian.org>
Subject: Re: [PATCH v9 1/1] net/af_xdp: introduce AF XDP PMD
 driver
Date: Wed, 03 Apr 2019 11:36:03 +0100
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References: <20190301080947.91086-1-xiaolong.ye@intel.com>
 <20190402154653.711-1-xiaolong.ye@intel.com>
 <20190402154653.711-2-xiaolong.ye@intel.com>
 <d2bf5816f98d715ff6e0575930f233e8b45732de.camel@debian.org>
 <20190403095939.GA32340@intel.com>
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Cc: dev@dpdk.org, Karlsson Magnus <magnus.karlsson@intel.com>, Topel Bjorn
 <bjorn.topel@intel.com>
To: Ye Xiaolong <xiaolong.ye@intel.com>
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On Wed, 2019-04-03 at 17:59 +0800, Ye Xiaolong wrote:
> Hi, Luca
>=20
> 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 $(RTE_SDK)/mk/rte.vars.mk
> > > +
> > > +#
> > > +# library name
> > > +#
> > > +LIB =3D librte_pmd_af_xdp.a
> > > +
> > > +EXPORT_MAP :=3D rte_pmd_af_xdp_version.map
> > > +
> > > +LIBABIVER :=3D 1
> > > +
> > > +CFLAGS +=3D -O3
> > > +
> > > +# require kernel version >=3D v5.1-rc1
> > > +CFLAGS +=3D -I$(RTE_KERNELDIR)/tools/include
> > > +CFLAGS +=3D -I$(RTE_KERNELDIR)/tools/lib/bpf
> >=20
> > 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.
>=20
> 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?
>=20
> Something like:
>=20
> dependencies:
> - kernel source code (>=3D v5.1-rc1)
> - build libbfp and install
>=20
> 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?

--=20
Kind regards,
Luca Boccassi