On Mon, Jan 20, 2020 at 05:50:55PM +0000, Jason Gunthorpe wrote:

On Mon, Jan 20, 2020 at 07:17:26AM -0500, Michael S. Tsirkin wrote:

quoted

On Fri, Jan 17, 2020 at 01:54:42PM +0000, Jason Gunthorpe wrote:

quoted

quoted

1) "virtio" vs "vhost", I implemented matching method for this in mdev
series, but it looks unnecessary for vDPA device driver to know about this.
Anyway we can use sysfs driver bind/unbind to switch drivers
2) virtio device id and vendor id. I'm not sure we need this consider the
two drivers so far (virtio/vhost) are all bus drivers.

As we seem to be contemplating some dynamic creation of vdpa devices I
think upon creation time it should be specified what mode they should
run it and then all driver binding and autoloading should happen
automatically. Telling the user to bind/unbind is a very poor
experience.

Maybe but OTOH it's an existing interface. I think we can reasonably
start with bind/unbind and then add ability to specify
the mode later. bind/unbind come from core so they will be
maintained anyway.

Existing where?

Driver core.

For vfio? vfio is the only thing I am aware doing
that, and this is not vfio..

Jason

vfio is not doing anything. anyone can use a combination
of unbind and driver_override to attach a driver to a device.

It's not a great interface but it's there without any code,
and it will stay there without maintainance overhead
if we later add a nicer one.

-- 
MST