[dpdk-dev] [PATCH v2] net/mlx: add meson build support

[Nélio Laranjeiro]

On Wed, Aug 29, 2018 at 11:00:54AM +0100, Luca Boccassi wrote:
> On Tue, 2018-08-28 at 16:45 +0100, Bruce Richardson wrote:
> > Thanks for this, comments inline below.
> > 
> > /Bruce
> > 
> > On Mon, Aug 27, 2018 at 02:42:25PM +0200, Nelio Laranjeiro wrote:
> > > Mellanox drivers remains un-compiled by default due to third party
> > > libraries dependencies.  They can be enabled through:
> > > - enable_driver_mlx{4,5}=true or
> > > - enable_driver_mlx{4,5}_glue=true
> > > depending on the needs.
> > 
> > The big reason why we wanted a new build system was to move away from
> > this
> > sort of static configuration. Instead, detect if the requirements as
> > present and build the driver if you can.
> > 
> > > 
> > > To avoid modifying the whole sources and keep the compatibility
> > > with
> > > current build systems (e.g. make), the mlx{4,5}_autoconf.h is still
> > > generated by invoking DPDK scripts though meson's run_command()
> > > instead
> > > of using has_types, has_members, ... commands.
> > > 
> > > Meson will try to find the required external libraries.  When they
> > > are
> > > not installed system wide, they can be provided though CFLAGS,
> > > LDFLAGS
> > > and LD_LIBRARY_PATH environment variables, example (considering
> > > RDMA-Core is installed in /tmp/rdma-core):
> > > 
> > >  # CLFAGS=-I/tmp/rdma-core/build/include \
> > >    LDFLAGS=-L/tmp/rdma-core/build/lib \
> > >    LD_LIBRARY_PATH=/tmp/rdma-core/build/lib \
> > >    meson -Denable_driver_mlx4=true output
> > > 
> > >  # CLFAGS=-I/tmp/rdma-core/build/include \
> > >    LDFLAGS=-L/tmp/rdma-core/build/lib \
> > >    LD_LIBRARY_PATH=/tmp/rdma-core/build/lib \
> > >    ninja -C output install
> > 
> > Once the CFLAGS/LDFLAGS are passed to meson, they should not be
> > needed for
> > ninja. The LD_LIBRARY_PATH might be - I'm not sure about that one! :-
> > )
> > 
> > > 
> > > Signed-off-by: Nelio Laranjeiro <nelio.laranjeiro at 6wind.com>
> > > 
> > > ---
> > > 
> > > Changes in v2:
> > > 
> > > - dropped patch https://patches.dpdk.org/patch/43897/
> > > - remove extra_{cflags,ldflags} as already honored by meson through
> > > environment variables.
> > > ---
> > >  drivers/net/meson.build      |   2 +
> > >  drivers/net/mlx4/meson.build |  94 ++++++
> > >  drivers/net/mlx5/meson.build | 545
> > > +++++++++++++++++++++++++++++++++++
> > >  meson_options.txt            |   8 +
> > >  4 files changed, 649 insertions(+)
> > >  create mode 100644 drivers/net/mlx4/meson.build
> > >  create mode 100644 drivers/net/mlx5/meson.build
> > > 
> > > diff --git a/drivers/net/meson.build b/drivers/net/meson.build
> > > index 9c28ed4da..c7a2d0e7d 100644
> > > --- a/drivers/net/meson.build
> > > +++ b/drivers/net/meson.build
> > > @@ -18,6 +18,8 @@ drivers = ['af_packet',
> > >  	'ixgbe',
> > >  	'kni',
> > >  	'liquidio',
> > > +	'mlx4',
> > > +	'mlx5',
> > >  	'mvpp2',
> > >  	'netvsc',
> > >  	'nfp',
> > > diff --git a/drivers/net/mlx4/meson.build
> > > b/drivers/net/mlx4/meson.build
> > > new file mode 100644
> > > index 000000000..debaca5b6
> > > --- /dev/null
> > > +++ b/drivers/net/mlx4/meson.build
> > > @@ -0,0 +1,94 @@
> > > +# SPDX-License-Identifier: BSD-3-Clause
> > > +# Copyright 2018 6WIND S.A.
> > > +# Copyright 2018 Mellanox Technologies, Ltd
> > > +
> > > +# As there is no more configuration file to activate/configure the
> > > PMD it will
> > > +# use some variables here to configure it.
> > > +pmd_dlopen = get_option('enable_driver_mlx4_glue')
> > > +build = get_option('enable_driver_mlx4') or pmd_dlopen
> > 
> > As stated above, I believe this should be based upon whether you find
> > the
> > "mnl", "mlx4" and "ibverbs" libraries. If we start adding back in
> > static
> > options for every driver, then we'll be back to having a mass of
> > config
> > options like we had before.
> 
> BTW, slightly related to that: ibverbs doesn't ship pkg-config files at
> the moment which makes the detection slightly more awkward that it
> could be, so I've sent a PR upstream to add that:
> 
> https://github.com/linux-rdma/rdma-core/pull/373
> 
> Hope this can be useful!

Thanks Luca, I was also searching for it, you save me some time, I hope
this can be backported down to RDMA-Core's stable version v15 of
RDMA-Core it would fully help.

-- 
Nélio Laranjeiro
6WIND