Re: [dpdk-dev] [PATCH v11 3/4] raw/ifpga: add OPAE API for OpenStack Cyborg

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

On 1/21/2021 6:03 AM, Wei Huang wrote:
> Cyborg is an OpenStack project that aims to provide a general purpose
> management framework for acceleration resources (i.e. various types
> of accelerators such as GPU, FPGA, NP, ODP, DPDK/SPDK and so on).
> It needs some OPAE type APIs to manage PACs (Programmable Acceleration
> Card) with Intel FPGA. Below major functions are added to meets
> Cyborg requirements.
> 1. opae_init() set up OPAE environment.
> 2. opae_cleanup() clean up OPAE environment.
> 3. opae_enumerate() searches PAC with specific FPGA.
> 4. opae_get_property() gets properties of FPGA.
> 5. opae_partial_reconfigure() perform partial configuration on FPGA.
> 6. opae_get_image_info() gets information of image file.
> 7. opae_update_flash() updates FPGA flash with specific image file.
> 8. opae_cancel_flash_update() cancel process of FPGA flash update.
> 9. opae_probe_device() manually probe specific FPGA with ifpga driver.
> 10. opae_remove_device() manually remove specific FPGA from ifpga driver.
> 11. opae_bind_driver() binds specific FPGA with specified kernel driver.
> 12. opae_unbind_driver() unbinds specific FPGA from kernel driver.
> 13. opae_reboot_device() reboots specific FPGA (do reconfiguration).
> 

Hi Wei,

As far as I understand you are adding above public functions which are on top of 
raw/ifpga driver functions, so they are like PMD specific APIs, I think there 
are a few problems with it:

1) Do we really need/want this much PMD specific API? Can't we have them through 
the rawdev abstraction layer?

2) DPDK public APIs are part of API/ABI policy, so there are a few rules they 
have to follow, like:
- They should start with 'rte_' prefix, and the PMD specific APIs should start 
with 'rte_pmd_' prefix
- They should be in the .map file
- They should be experimental at least one release
- They should be fully documented in a doxygen format
   - Header file should be added to index file for API documentation

Please don't update above before 1) is clearified and we are sure new APIs are 
required.

<...>

> @@ -13,8 +13,10 @@ objs = [base_objs]
>   deps += ['ethdev', 'rawdev', 'pci', 'bus_pci', 'kvargs',
>   	'bus_vdev', 'bus_ifpga', 'net', 'net_i40e', 'net_ipn3ke']
>   
> -sources = files('ifpga_rawdev.c')
> +sources = files('ifpga_rawdev.c', 'ifpga_opae_api.c')
>   
>   includes += include_directories('base')
>   includes += include_directories('../../net/ipn3ke')
>   includes += include_directories('../../net/i40e')
> +
> +install_headers('ifpga_opae_api.h')
> 

There is a 'headers' helper that you can use for meson. Also the header file 
name should start with 'rte_pmd_'.

Even before this patch, isn't application has to include the rawdev PMD header? 
Why that header was not installed?