Re: [dpdk-dev] [RFC 00/14] mlx5: support SubFunction

Hi Chenbo,

From: Xia, Chenbo <redacted>
Sent: Tuesday, June 15, 2021 7:41 AM

Hi Thomas,

quoted

From: Thomas Monjalon <redacted>
Sent: Friday, June 11, 2021 3:54 PM

[..]

Yes. In our term it's called Assignable Device Interface (ADI) introduced in
Intel Scalable IOV (https://01.org/blogs/2019/assignable-interfaces-intel-
scalable-i/o-virtualization-linux)

And vfio-mdev is chosen to be the software framework for it. I start to realize
there is difference between SF and ADI: SF considers multi-function devices
which may include net/regex/vdpa/... 

Yes. net, rdma, vdpa, regex ++.
And eventually vfio_device to map to VM too.

Non mdev framework is chosen so that all the use cases of kernel only, or user only or mix modes can be supported.

But ADI only focuses on the
virtualization of the devices and splitting devices to logic parts and providing
huge number of interfaces to host APP. I think SF also considers this but is
mainly used for multi-function devices (like DPU in your term?
Correct me if I'm wrong).

SF also supports DPU mode too but it is in addition to above use cases.
SF will expose mdev (or a vfio_device) to map to a VM.

And I also noticed that the mdev-based interface can only be used in
userspace but aux-based interface can also be used by other kernel sub-
system (like for net, wrap it as netdev).

Correct.