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

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 4/3/2019 1:16 PM, Luca Boccassi wrote:
> On Wed, 2019-04-03 at 12:35 +0100, Luca Boccassi wrote:
>> On Wed, 2019-04-03 at 12:18 +0100, Ferruh Yigit wrote:
>>> On 4/3/2019 11:42 AM, Luca Boccassi wrote:
>>>> On Wed, 2019-04-03 at 11:36 +0100, Luca Boccassi wrote:
>>>>> 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?
>>>>
>>>> Actually, xsk.h is now installed by the library makefile:
>>>>
>>>> https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=379e2014c95b
>>>>
>>>>
>>>
>>> Good to have this one. But again it is in BPF tree and it won't be
>>> in
>>> 5.1.
>>
>> It looks like a small and required bug fix to me, and 5.1 is still in
>> RC state, so perhaps there's still time.
>>
>> Bjorn and Magnus, any chance the above makefile install fix could be
>> sent for inclusion in 5.1-rc4?
> 
> Actually the bpf tree was already merged in the net tree a couple of
> days ago. As far as I understand from the process, this should mean
> that this fix should be set for inclusion in Linus' tree in time for
> 5.1-rc4:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git/commit?id=379e2014c95b7a454713da822b8ef4ec51ab8a75
> 

My bad, it seems 'bpf' tree can be merged into 'net' tree, but also there is
another 'bpf-next' for further releases.

So I believe it is OK to expect the fixes you pointed in 'bpf' tree to be in 5.1