Re: [PATCH V10 6/6] docs: sample driver to demonstrate how to implement virtio-mdev framework

From: Jason Wang
Date: Thu Nov 07 2019 - 08:41:03 EST



On 2019/11/7 äå9:08, Michael S. Tsirkin wrote:
On Thu, Nov 07, 2019 at 08:47:06PM +0800, Jason Wang wrote:
On 2019/11/7 äå8:43, Jason Wang wrote:
On 2019/11/7 äå7:21, Michael S. Tsirkin wrote:
On Thu, Nov 07, 2019 at 06:18:45PM +0800, Jason Wang wrote:
On 2019/11/7 äå5:08, Michael S. Tsirkin wrote:
On Wed, Nov 06, 2019 at 09:35:31PM +0800, Jason Wang wrote:
This sample driver creates mdev device that simulate
virtio net device
over virtio mdev transport. The device is implemented through vringh
and workqueue. A device specific dma ops is to make sure HVA is used
directly as the IOVA. This should be sufficient for kernel virtio
driver to work.

Only 'virtio' type is supported right now. I plan to add 'vhost' type
on top which requires some virtual IOMMU implemented in this sample
driver.

Acked-by: Cornelia Huck<cohuck@xxxxxxxxxx>
Signed-off-by: Jason Wang<jasowang@xxxxxxxxxx>
I'd prefer it that we call this something else, e.g.
mvnet-loopback. Just so people don't expect a fully
functional device somehow. Can be renamed when applying?
Actually, I plan to extend it as another standard network interface for
kernel. It could be either a standalone pseudo device or a stack
device.
Does this sounds good to you?

Thanks
That's a big change in an interface so it's a good reason
to rename the driver at that point right?
Oherwise users of an old kernel would expect a stacked driver
and get a loopback instead.

Or did I miss something?

My understanding is that it was a sample driver in /doc. It should not
be used in production environment. Otherwise we need to move it to
driver/virtio.

But if you insist, I can post a V11.

Thanks

Or maybe it's better to rename the type of current mdev from 'virtio' to
'virtio-loopback'. Then we can add more types in the future.

Thanks

Maybe but is virtio actually a loopback somehow? I thought we
can bind a regular virtio device there, no?


It has a prefix, so user will see "mvnet-virtio-loopback".

Thanks