Re: [Qemu-devel] [PATCH 3/4] cryptodev-vhost-user: add crypto session handler

[Gonglei (Arei)]

> -----Original Message-----
> From: Paolo Bonzini [mailto:address@hidden
> Sent: Tuesday, November 28, 2017 6:46 PM
> To: Gonglei (Arei); address@hidden
> Cc: address@hidden; Huangweidong (C); address@hidden; Zhoujian
> (jay); address@hidden; longpeng; address@hidden;
> address@hidden
> Subject: Re: [PATCH 3/4] cryptodev-vhost-user: add crypto session handler
> 
> On 28/11/2017 11:43, Gonglei (Arei) wrote:
> >> As far as I understand, VIRTIO_CRYPTO_CIPHER_CREATE_SESSION is called
> as
> >> a result of sending a message on the control virtqueue.
> >
> > VIRTIO_CRYPTO_CIPHER_CREATE_SESSION is a message type of control
> queue,
> > Means creating a session for next crypto requests.
> 
> Ok, so the message does have the same meaning as the control queue
> message.  Thanks for confirming.
> 
> >> Why can't vhost-user also process create/destroy session messages on the
> >> control virtqueue, instead of having device-specific messages in the
> >> protocol?
> >
> > You mean we can share control virtqueue to DPDK as well? Like data queues?
> 
> I don't know :) but why not?
> 
Current there are two main reasons for this design:

1) we should use another cpu to polling the control virtqueue, which is 
expensive.
2) we should copy the logic of parsing control message to DPDK, which break
 current layered architecture .

I'm not sure if there are any other hidden issues for future scalability, such 
as
using Qemu to manage some control messages, avoiding D-Dos attack etc.

Thanks,
-Gonglei