Virtualization - Nov 2021 - question about vdpa_mgmt_dev

Hi Experts
	I have read the upstream code about vdpa, and I notice that there is a new
struct vdpa_mgmt_dev have been added.
	Every driver implements dev_add() interface, such as mlx5 use
mlx5_vdpa_dev_add(). This interface completes the creation of the vdpa device,
hardware initialization and system registration. And I found that only netlink
will call the dev_add() interface, in vdpa_nl_cmd_dev_add_set_doit(). While the
probe() function just register vdpa_mgmt_dev without call dev_add()
	So, my questions are:
	Does it create a vdpa device only through the netlink interface? The system
scans the PCI device and does not automatically create the corresponding vdpa
device?
	

Thanks
Feng

On Mon, Nov 15, 2021 at 2:08 PM Liu,Feng(INF) <liufeng32 at baidu.com>
wrote:
>
> Hi Experts
>         I have read the upstream code about vdpa, and I notice that there
is a new struct vdpa_mgmt_dev have been added.
>         Every driver implements dev_add() interface, such as mlx5 use
mlx5_vdpa_dev_add(). This interface completes the creation of the vdpa device,
hardware initialization and system registration. And I found that only netlink
will call the dev_add() interface, in vdpa_nl_cmd_dev_add_set_doit(). While the
probe() function just register vdpa_mgmt_dev without call dev_add()
>         So, my questions are:
>         Does it create a vdpa device only through the netlink interface?
Yes, this is the plan, and we're working on converting all the drivers
to support that.
> The system scans the PCI device and does not automatically create the
corresponding vdpa device?
It's a choice for the vDPA parent driver but we suggest creating vDPA
via netlink(), this gives a persistent method for the management
layer.

Thanks
>
>
> Thanks
> Feng
>