Re: virtio crypto device implemenation

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, May 23, 2017 at 04:08:25PM +0000, Zeng, Xin wrote:
> Hi, Michael, 
>    As you know, Lei Gong from Huawei and I are co-working  on virtio crypto device spec, he is focusing on symmetric algorithm part, I am focusing on asymmetric part.  Now I am planning the implementation for asymmetric part, would you please give me your point regarding the questions below?
>    Current virtio crypto device implementation from Lei Gong:
>    The virtio crypto device implementation has been upstreamed to QEMU and it has a qemu backend implementation for symmetric algorithm part, the front end Linux device driver for symmetric part has been upstreamed to Linux kernel as well.
>    My questions:
>    From my side, I planned to add the asymmetric part support in upstreamed front end device driver, and I don't want to add the asymmetric algorithm support to current virtio crypto device's qemu backend, instead, I would like to implement and upstream a DPDK vhost-user based backend for asymmetric algorithm, and accordingly Lei Gong will help to upstream a vhost user agent for virtio crypto device in QEMU,  is this approach acceptable? Is a qemu backend a mandatory requirement for the virtio crypto device?  Is there a general policy for this?
> 
> Thanks

Parity on QEMU side is naturally preferable.  I don't think we should require it
at all times, but if there's no implementation outside vhost-user,
and if the feature includes a non-trivial amount of code, how
will it be tested? I don't think we want to require all testers to use
dpdk. An implementation under tests using libvhost-user might
be a solution.

-- 
MST