Re: [PATCH v11 0/4] crypto: spacc - Add SPAcc Crypto Driver

[Tony He]

Hi Ruud,

Thanks for your quick reply.

I would like to confirm my understanding regarding the use of
SPAcc as a pure crypto engine in IPsec scenarios.

My concern is that the main bottleneck may not be the crypto
throughput itself, but the per-packet overhead, such as
descriptor setup, submission, and DMA cost. Since IPsec traffic
typically operates at MTU-sized packets (~1500 bytes), this
per-packet cost may significantly reduce the overall benefit of
offloading.

In other words, for MTU-sized traffic, the performance gain from
a pure crypto engine might be limited, or in some cases even
offset by the overhead of per-packet scheduling and DMA.

Could you please confirm whether this understanding is correct?

Also, do you happen to have any performance data for network
workloads (e.g., IPsec throughput), comparing:

1)with SPAcc enabled

2)without SPAcc (software crypto)

It would be very helpful to understand the actual benefit in
real-world scenarios.

Thanks.

Tony

On Fri, Apr 3, 2026 at 3:59 PM Ruud Derwig <Ruud.Derwig@xxxxxxxxxxxx> wrote:
>
> Hi Tony,
>
> > Is SPAcc capable of handling full ESP packet processing (i.e.,
> > beyond basic encryption/decryption and authentication)?
>
> No, SPAcc only implements the crypto algorithms.
> (The name/documentation only shows that it was designed to
> support the crypto algorithms of various communication protocols.)
>
> Regards,
>
> Ruud.
>