Linux Virtualization - Sep 2019 - [PATCH V2 6/8] mdev: introduce virtio device and its device ops

On Thu, Sep 26, 2019 at 12:04:46PM +0800, Jason Wang
wrote:
> > > > I'm not sure how stable above ops are.
> > > It's the kernel internal API, so there's no strict
requirement for this. We
> > > will export a version value for userspace for compatibility.
> > Given it's tied to virtio we probably want kernel+userspace
> > feature bits?
> 
> 
> Yes, then I think we could probably have a version field inside e.g
> device_ops structure. Then it could be fetched from both kernel and
> userspace driver.
> 
> Thanks
> 

my point was feature bits not a version number.
> >

On 2019/9/26 ??4:21, Michael S. Tsirkin wrote:
> On Thu, Sep 26, 2019 at 12:04:46PM +0800, Jason Wang wrote:
>>>>> I'm not sure how stable above ops are.
>>>> It's the kernel internal API, so there's no strict
requirement for this. We
>>>> will export a version value for userspace for compatibility.
>>> Given it's tied to virtio we probably want kernel+userspace
>>> feature bits?
>>
>> Yes, then I think we could probably have a version field inside e.g
>> device_ops structure. Then it could be fetched from both kernel and
>> userspace driver.
>>
>> Thanks
>>
>
> my point was feature bits not a version number.

Something like backend_feature that current vhost_net did?

Thanks

>

On Thu, Sep 26, 2019 at 06:48:54PM +0800, Jason Wang
wrote:
> 
> On 2019/9/26 ??4:21, Michael S. Tsirkin wrote:
> > On Thu, Sep 26, 2019 at 12:04:46PM +0800, Jason Wang wrote:
> > > > > > I'm not sure how stable above ops are.
> > > > > It's the kernel internal API, so there's no
strict requirement for this. We
> > > > > will export a version value for userspace for
compatibility.
> > > > Given it's tied to virtio we probably want
kernel+userspace
> > > > feature bits?
> > > 
> > > Yes, then I think we could probably have a version field inside
e.g
> > > device_ops structure. Then it could be fetched from both kernel
and
> > > userspace driver.
> > > 
> > > Thanks
> > > 
> > 
> > my point was feature bits not a version number.
> 
> 
> Something like backend_feature that current vhost_net did?
> 
> Thanks
> 
> 
> > 
right