Re: [dpdk-dev] [PATCH] kernel/linux: fix kernel dir for meson

[Ye Xiaolong <xiaolong.ye@intel.com>]

Hi, Igor

Thanks for the feedback.

On 12/02, Igor Ryzhov wrote:
>Hi Xiaolong,
>
>Nack from me. It's just an incorrect revert of my fix.
>Kernel modules will be installed in wrong directory, just check install_dir

Is there any convention that we must install kernel modules to which directory?
And what about for cross compilation case? 

Current issue is that if I specify kernel_dir as one local linux src dir in meson_options.txt,
meson build would fail to compile kernel modules while setting RTE_KERNELDIR='/<xxx>/build_dir/target-x86_64_glibc/linux-x86_64/linux-4.19.81/'
before make works fine. Is there any subtlety I have missed?

Thanks,
Xiaolong

>parameter in kni/meson.build and igb_uio/meson.build.
>
>Igor
>
>On Mon, Dec 2, 2019 at 9:18 AM Xiaolong Ye <xiaolong.ye@intel.com> wrote:
>
>> kernel_dir option in meson build is equivalent to RTE_KERNELDIR in make
>> system, for cross-compilation case, users would specify it as local
>> kernel src dir like
>>
>> /<user local dir>/target-arm_glibc/linux-arm/linux-4.19.81/
>>
>> Current meson build would fail to compile kernel module if user specify
>> kernel_dir as above, this patch fixes this issue.
>>
>> Fixes: 317832f97c16 ("kernel/linux: fix modules install path")
>> Cc: stable@dpdk.org
>> Cc: iryzhov@nfware.com
>>
>> Signed-off-by: Xiaolong Ye <xiaolong.ye@intel.com>
>> ---
>>  kernel/linux/igb_uio/meson.build | 2 +-
>>  kernel/linux/kni/meson.build     | 2 +-
>>  kernel/linux/meson.build         | 4 ++--
>>  meson_options.txt                | 2 +-
>>  4 files changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/kernel/linux/igb_uio/meson.build
>> b/kernel/linux/igb_uio/meson.build
>> index fac404f07..e66218dae 100644
>> --- a/kernel/linux/igb_uio/meson.build
>> +++ b/kernel/linux/igb_uio/meson.build
>> @@ -8,7 +8,7 @@ mkfile = custom_target('igb_uio_makefile',
>>  custom_target('igb_uio',
>>         input: ['igb_uio.c', 'Kbuild'],
>>         output: 'igb_uio.ko',
>> -       command: ['make', '-C', kernel_dir + '/build',
>> +       command: ['make', '-C', kernel_dir,
>>                 'M=' + meson.current_build_dir(),
>>                 'src=' + meson.current_source_dir(),
>>                 'EXTRA_CFLAGS=-I' + meson.current_source_dir() +
>> diff --git a/kernel/linux/kni/meson.build b/kernel/linux/kni/meson.build
>> index 955eec949..9fce0c16e 100644
>> --- a/kernel/linux/kni/meson.build
>> +++ b/kernel/linux/kni/meson.build
>> @@ -13,7 +13,7 @@ kni_sources = files(
>>  custom_target('rte_kni',
>>         input: kni_sources,
>>         output: 'rte_kni.ko',
>> -       command: ['make', '-j4', '-C', kernel_dir + '/build',
>> +       command: ['make', '-j4', '-C', kernel_dir,
>>                 'M=' + meson.current_build_dir(),
>>                 'src=' + meson.current_source_dir(),
>>                 'MODULE_CFLAGS=-include ' + meson.source_root() +
>> '/config/rte_config.h' +
>> diff --git a/kernel/linux/meson.build b/kernel/linux/meson.build
>> index 1796cc686..a37c95752 100644
>> --- a/kernel/linux/meson.build
>> +++ b/kernel/linux/meson.build
>> @@ -13,11 +13,11 @@ kernel_dir = get_option('kernel_dir')
>>  if kernel_dir == ''
>>         # use default path for native builds
>>         kernel_version = run_command('uname', '-r').stdout().strip()
>> -       kernel_dir = '/lib/modules/' + kernel_version
>> +       kernel_dir = '/lib/modules/' + kernel_version + '/build'
>>  endif
>>
>>  # test running make in kernel directory, using "make kernelversion"
>> -make_returncode = run_command('make', '-sC', kernel_dir + '/build',
>> +make_returncode = run_command('make', '-sC', kernel_dir,
>>                 'kernelversion').returncode()
>>  if make_returncode != 0
>>         warning('Cannot compile kernel modules as requested - are kernel
>> headers installed?')
>> diff --git a/meson_options.txt b/meson_options.txt
>> index bc369d06c..7eba3b720 100644
>> --- a/meson_options.txt
>> +++ b/meson_options.txt
>> @@ -17,7 +17,7 @@ option('ibverbs_link', type: 'combo', choices :
>> ['shared', 'dlopen'], value: 'sh
>>  option('include_subdir_arch', type: 'string', value: '',
>>         description: 'subdirectory where to install arch-dependent
>> headers')
>>  option('kernel_dir', type: 'string', value: '',
>> -       description: 'Path to the kernel for building kernel modules.
>> Headers must be in $kernel_dir/build. Modules will be installed in
>> $DEST_DIR/$kernel_dir/extra/dpdk.')
>> +       description: 'Path to the kernel for building kernel modules.
>> Modules will be installed in $DEST_DIR/$kernel_dir/extra/dpdk.')
>>  option('lib_musdk_dir', type: 'string', value: '',
>>         description: 'path to the MUSDK library installation directory')
>>  option('machine', type: 'string', value: 'native',
>> --
>> 2.17.1
>>
>>