Re: [virtio-dev] packed ring layout proposal - todo list

[Yuanhan Liu <yuanhan.liu@linux.intel.com>]

Hi Michael,

Again, as usual, sorry for being late :/

On Wed, Feb 22, 2017 at 06:27:11AM +0200, Michael S. Tsirkin wrote:
> Stage 2: prototype guest/host drivers
> 
> At this stage we need real guest and host drivers
> to be able to test real life performance.
> I suggest dpdk drivers + munimal hack in qemu to
> pass features around.
> 

I have already done that in last Nov. I made a very rough (yet hacky)
version (only with Tx path) in one day while companying my wife in
hospital.

If someone are interested in, I could share the code soon. I could
even cleanup the code a bit if necessary.


> Tasks:
> 
> - implement vhost-user support in dpdk
> - implement virtio support in dpdk
> - implement minimal stub in qemu

I didn't hack the QEMU, instead, I hacked the DPDK virtio-user, yet
another virtio-net emulation. It's simpler and quicker for me.

And here is my plan on virtio 1.1:

- Look deeper inside the virtio net performance issues (WIP)

  It's basically a job about digging the DPDK vhost/virtio code
  deeper, something like how exactly the cache acts while Tx/Rx
  pkts, what can be optimized by implementation, and what could
  be improved with the help of spec extension.

  Please note that I often got interrupted on this task: it didn't
  go smooth as I would have expected.


- Try to accelerate vhost/virtio with vector instructions.

  Something I will look into when above item is done. Currently,
  I thought of two items may help the vector implementation:

  * what kind of vring and desc layout could make the vector
    implementation easier.

  * what kind of hint we need from virtio spec for (dynamically)
    enabling the vector path.

  Besides that, I don't have too much clue yet.

	--yliu