[dpdk-dev] [PATCH 3/4] crypto: add sgl support for sw PMDs

[Kulasek, TomaszX]

Hi Michał,

> -----Original Message-----
> From: Michał Mirosław [mailto:mirqus at gmail.com]
> Sent: Saturday, December 3, 2016 09:28
> To: Kulasek, TomaszX <tomaszx.kulasek at intel.com>
> Cc: dev at dpdk.org
> Subject: Re: [dpdk-dev] [PATCH 3/4] crypto: add sgl support for sw PMDs
> 
> 2016-12-02 18:07 GMT+01:00 Tomasz Kulasek <tomaszx.kulasek at intel.com>:
> > This patch introduces RTE_CRYPTODEV_FF_MBUF_SCATTER_GATHER feature
> > flag informing that selected crypto device supports segmented mbufs
> > natively and doesn't need to be coalesced before crypto operation.
> >
> > While using segmented buffers in crypto devices may have unpredictable
> > results, for PMDs which doesn't support it natively, additional check
> > is made for debug compilation.
> >
> [...]
> > +#ifdef RTE_LIBRTE_PMD_AESNI_GCM_DEBUG
> > +               if (!rte_pktmbuf_is_contiguous(ops[i]->sym->m_src) ||
> > +                               (ops[i]->sym->m_dst != NULL &&
> > +                               !rte_pktmbuf_is_contiguous(
> > +                                               ops[i]->sym->m_dst))) {
> > +                       ops[i]->status =
> RTE_CRYPTO_OP_STATUS_INVALID_ARGS;
> > +                       GCM_LOG_ERR("PMD supports only contiguous mbufs,
> "
> > +                               "op (%p) provides noncontiguous mbuf as
> "
> > +                               "source/destination buffer.\n", ops[i]);
> > +                       qp->qp_stats.enqueue_err_count++;
> > +                       break;
> > +               }
> > +#endif
> [...]
> 
> Why are there so many copies of this code?
> 
> Best Regards,
> Michał Mirosław

This is one check per crypto PMD: aesni-gcm, aesni-mb, openssl and so on, enabled per PMD.

Tomasz