Re: [Qemu-devel] [RFC-PATCH] Introducing virtio-example device.

[Yoni Bettan <ybettan@redhat.com>]

On 4/10/19 10:25 PM, Stefan Hajnoczi wrote:
> On Wed, Apr 10, 2019 at 4:45 PM Yoni Bettan <ybettan@redhat.com> wrote:
>> On 4/9/19 4:17 PM, Stefan Hajnoczi wrote:
>>> On Mon, Apr 01, 2019 at 02:18:43PM +0300, Yoni Bettan wrote:
>>> There are multiple problems with the code, but the larger issue is that
>>> this example device is just helping people shoot themselves in the foot
>>> more easily.
>>
>> If you can point me to those problem I will be glad so I can update the
>> code and understand those problems you are talking about.
> Please see Eduardo's reply.  I didn't review much since he already
> pointed out many things.
>
> One thing he didn't mention:
> +    elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
>
> The return value can be NULL.  Spurious notifications could happen so
> the code shouldn't crash when this returns NULL.
>
> I apologize for the critical replies.  What you're doing is valuable.
> I think explaining the VIRTIO device model and the order in which
> things are done will lead to higher quality devices so I'm making a
> lot of noise about it :).


It is OK, I will write some basic specification for the device and start 
iterating spec-device-driver according to Rustie's paper, Eduardo's 
review, and you advice.


Thanks.

>
> Stefan