[dpdk-dev] driver initialization in DPDK 2.0 built into a shared library.

[Zoltan Kiss]

On 14/07/15 19:21, Polevoy, Igor wrote:
> Hi,
> We are developing an application that uses DPDK PMD functionality .
> We are using a linux shared library which contains the network packets processing code and it is statically linked with all the necessary DPDK libs.
> The .so is loaded by the main program.
> For the DPDK compilation we have added the -fPIC to the GCC options.
>
> While it all worked fine with DPDK 1.6 where we had the rte_pmd_init_all method, in the 2.0 version the
> drivers registration methods (PMD_REGISTER_DRIVER) are not called when the shared library is loaded.
>
> Although, I can go along the lines of the rte_pmd_init all and manually call the driver registration, I'm concerned
> that DPDK has other drivers initialization calls, and I don't actually know which are needed or could be needed and when.
>
> Do you have any advice on that? What is the best way to resolve this issue?
>
> Thank you
> Igor.
>

I've seen a similar problem, but in a different setup. My app (OVS) 
links to ODP-DPDK statically, which then links to DPDK code statically. 
I found that the devinitfn_* functions are not called because OVS 
doesn't call directly into the DPDK library, only into ODP-DPDK. The 
workaround for me was to refer to those functions in the ODP-DPDK code:

#define PMD_EXT(drv)  extern void devinitfn_##drv(void);
PMD_EXT(bond_drv)
PMD_EXT(em_pmd_drv)
...

But there might be better solutions than that. This one is fragile, if 
you update DPDK you have to remember adding these references for new PMDs.

Zoli